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Title:
ANTENNA SYSTEMS WITH ADJUSTABLE PHASE DELAY ELEMENTS HAVING CONFIGURABLE DIELECTRIC COMPOSITIONS
Document Type and Number:
WIPO Patent Application WO/2019/190849
Kind Code:
A1
Abstract:
An antenna includes a delay element that is configured to generate a phase delayed output signal responsive to an input signal, the phase delayed output signal having a phase delay based on a frequency of the input signal, the delay element including: a variable capacitor including a conductive line element and a ground plane element separated by a vessel containing a dielectric, the dielectric including a composition of fluid and gas in proportions that are adjustable responsive to forces applied at opposing ends of the vessel, respectively. A radiating element is responsive to the phase delayed output signal.

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Inventors:
VANDERHOOF, Troy I. (3601 Spicewood Drive, Prosper, Texas, 75078, US)
Application Number:
US2019/023112
Publication Date:
October 03, 2019
Filing Date:
March 20, 2019
Export Citation:
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Assignee:
COMMSCOPE TECHNOLOGIES LLC (1100 CommScope Place SE, Hickory, North Carolina, 28602, US)
International Classes:
H01Q3/26
Domestic Patent References:
WO2017176822A12017-10-12
WO2017176372A12017-10-12
Foreign References:
US20040264107A12004-12-30
US20040090369A12004-05-13
US20160013563A12016-01-14
US20090058731A12009-03-05
Attorney, Agent or Firm:
MOORE, Scott D. (MYERS BIGEL, P.A.PO Box 3742, Raleigh North Carolina, 27627, US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. An antenna, comprising:

a delay element that is configured to generate a phase delayed output signal responsive to an input signal, the phase delayed output signal having a phase delay based on a frequency of the input signal, the delay element comprising:

a variable capacitor comprising a conductive line element and a ground plane element separated by a vessel containing a dielectric, the dielectric comprising a composition of fluid and gas in proportions that are adjustable responsive to forces applied at opposing ends of the vessel, respectively;

a radiating element that is responsive to the phase delayed output signal.

2. The antenna of Claim 1, further comprising:

a power divider that is configured to generate a first divided output signal and a second divided output signal responsive to the input signal;

wherein the delay element is configured to generate the phase delayed output signal responsive to the second divided output signal, the phase delayed output signal having the phase delay based on a frequency of the second divided output signal.

3. The antenna of Claim 2, further comprising:

a directional coupler that is configured to generate the output signal responsive to the phase delayed output signal and the first divided output signal.

4. The antenna of Claim 3, wherein the directional coupler is a 90° hybrid branch-line coupler having an operational bandwidth within a range of approximately 690 MHz - 2700 MHz.

5. The antenna of Claim 3, further comprising:

a stub circuit configured to generate first and second coupler input signals responsive to the phase delayed output signal and the first divided output signal;

wherein the directional coupler is configured to generate the output signal responsive to the first and second coupler input signals.

6. The antenna of Claim 4, wherein the stub circuit comprises a pair of quarter- wave shorted lines.

7. The antenna of Claim 4, wherein the stub circuit comprises a pair of half-wave open ended lines.

8. The antenna of any of Claims 4, wherein an input impedance of the stub circuit is capacitive.

9. The antenna of any of Claims 4, wherein an input impedance of the stub circuit is inductive.

10. The antenna of Claim 1, wherein the fluid comprises glycerin and the gas comprises air.

11. The antenna of Claim 1 , wherein the fluid comprises glycerin and the gas comprises an inert gas.

12. The antenna of Claim 1, further comprising:

a processing unit that is configured to determine a volume of the gas in the vessel based on a temperature measurement and a pressure measurement of the gas.

13. The antenna of Claim 1, further comprising:

an optical sensor that is configured to determine the proportions of the fluid and gas, respectively, in the vessel.

14. The antenna of Claim 1 , further comprising:

a float switch that is configured to determine the proportions of the fluid and gas, respectively, in the vessel.

15. The antenna of Claim 1 , further comprising:

first and second force elements; and

first and second pressure regulators that connect the first and second force elements to the opposing ends of the vessel, respectively.

16. The antenna of Claim 15, wherein the first and second force elements comprise first and second pressurized gas canisters, respectively; and

wherein the first and second pressure regulators comprise first and second proportional valves, respectively.

17. The antenna of Claim 1, wherein the ground plane element is a first ground plane element, the variable capacitor further comprising:

a second ground plane element, the conductive line element being spaced apart from the first ground plane element by the dielectric in a first portion of the vessel and being spaced apart from the second ground plane element by the dielectric in a second portion of the vessel.

18. The antenna of Claim 17, further comprising:

a force element;

a force distribution manifold connected to the force element; and

first and second pressure regulators that connect the force distribution manifold to the opposing ends of the vessel, respectively.

19. The antenna of Claim 18, wherein the force element comprises a pressurized gas canister; and

wherein the first and second pressure regulators comprise first and second proportional valves, respectively.

20. The antenna of Claim 17, wherein the vessel is oriented so that gravitational force at least partially resists entry of the fluid into the vessel.

21. The antenna of Claim 20, further comprising:

a fluid pump connected to a first one of the opposing ends of the vessel; and a flow control orifice connected to a second one of the opposing ends of the vessel.

22. The antenna of Claim 21, further comprising:

a ball type pressure relief valve connected to the flow control orifice.

23. The antenna of Claim 21 , further comprising:

a piston type pressure relief valve connected to the flow control orifice.

24. The antenna of Claim 20, further comprising:

a fluid pump connected to a first one of the opposing ends of the vessel;

a pressure regulator connected to a second one of the opposing ends of the vessel; and a force element connected to the second one of the opposing ends of the vessel.

25. The antenna of Claim 24, wherein the pressure regulator comprises a proportional valve and the force element comprises a pressurized gas canister.

26. The antenna of Claim 1 , wherein the ground plane element is a first ground plane element, the vessel is a first vessel, and the dielectric is a first dielectric, the variable capacitor further comprising:

a second ground plane element, the conductive line element being spaced apart from the first ground plane element by the first dielectric in the first vessel and being spaced apart from the second ground plane element by the second dielectric in the second vessel.

27. The antenna of Claim 26, further comprising:

a force element;

a force distribution manifold connected to the force element;

first and second pressure regulators that connect the force distribution manifold to the opposing ends of the first vessel, respectively; and

third and fourth pressure regulators that connect the force distribution manifold to opposing ends of the second vessel, respectively.

28. The antenna of Claim 27, wherein the force element comprises a pressurized gas canister; and

wherein the first, second, third, and fourth pressure regulators comprise first, second, third, and fourth proportional valves, respectively.

29. The antenna of Claim 1, wherein the vessel comprises an elastic material that is configured to expand and contract responsive the forces applied at the opposing ends of the vessel.

30. An electronic device, comprising:

a variable capacitor comprising a conductive line element and a ground plane element separated by a vessel containing a dielectric, the dielectric comprising a composition of fluid and gas in proportions that are adjustable responsive to forces applied at opposing ends of the vessel, respectively.

31. The electronic device of Claim 30, further comprising:

first and second force elements; and

first and second pressure regulators that connect the first and second force elements to the opposing ends of the vessel, respectively.

32. The electronic device of Claim 31, wherein the first and second force elements comprise first and second pressurized gas canisters, respectively; and

wherein the first and second pressure regulators comprise first and second

proportional valves, respectively.

33. The electronic device of Claim 30, wherein the ground plane element is a first ground plane element, the variable capacitor further comprising:

a second ground plane element, the conductive line element being spaced apart from the first ground plane element by the dielectric in a first portion of the vessel and being spaced apart from the second ground plane element by the dielectric in a second portion of the vessel.

34. The electronic device of Claim 33, further comprising:

a force element;

a force distribution manifold connected to the force element; and

first and second pressure regulators that connect the force distribution manifold to the opposing ends of the vessel, respectively.

35. The electronic device of Claim 34, wherein the force element comprises a pressurized gas canister; and

wherein the first and second pressure regulators comprise first and second

proportional valves, respectively.

36. The electronic device of Claim 33, wherein the vessel is oriented so that gravitational force at least partially resists entry of the fluid into the vessel.

37. The electronic device of Claim 36, further comprising:

a fluid pump connected to a first one of the opposing ends of the vessel; and a flow control orifice connected to a second one of the opposing ends of the vessel.

38. The electronic device of Claim 37, further comprising:

a ball type pressure relief valve connected to the flow control orifice.

39. The electronic device of Claim 37, further comprising:

a piston type pressure relief valve connected to the flow control orifice.

40. The electronic device of Claim 36, further comprising:

a fluid pump connected to a first one of the opposing ends of the vessel;

a pressure regulator connected to a second one of the opposing ends of the vessel; and a force element connected to the second one of the opposing ends of the vessel.

41. The electronic device of Claim 40, wherein the pressure regulator comprises a proportional valve and the force element comprises a pressurized gas canister.

42. The electronic device of Claim 30, wherein the ground plane element is a first ground plane element, the vessel is a first vessel, and the dielectric is a first dielectric, the variable capacitor further comprising:

a second ground plane element, the conductive line element being spaced apart from the first ground plane element by the first dielectric in the first vessel and being spaced apart from the second ground plane element by the second dielectric in the second vessel.

43. The electronic device of Claim 42, further comprising:

a force element;

a force distribution manifold connected to the force element;

first and second pressure regulators that connect the force distribution manifold to the opposing ends of the first vessel, respectively; and third and fourth pressure regulators that connect the force distribution manifold to opposing ends of the second vessel, respectively.

44. The electronic device of Claim 43, wherein the force element comprises a pressurized gas canister; and

wherein the first, second, third, and fourth pressure regulators comprise first, second, third, and fourth proportional valves, respectively.

45. The electronic device of Claim 30, wherein the vessel comprises an elastic material that is configured to expand and contract responsive the forces applied at the opposing ends of the vessel.

46. An antenna, comprising:

a radiating element configured to generate a radio frequency signal pattern; and a lens configured to receive the radio frequency signal pattern therethrough, the lens comprising a vessel containing a dielectric comprising a composition of fluid and gas, the vessel having a volume that is adjustable responsive to force applied to at least one end of the vessel.

47. The antenna of Claim 46, wherein the fluid comprises glycerin and the gas comprises air.

48. The antenna of Claim 46, wherein the fluid comprises glycerin and the gas comprises an inert gas.

49. The antenna of Claim 46, wherein the dielectric comprises dielectric particles.

50. The antenna of Claim 49, wherein each of the dielectric particles has a density in a range from about 0.005 to about 0.1 g/cm3.

51. The antenna of Claim 50, wherein each of the particles comprises at least one conductive fiber.

52. The antenna of Claim 51 , wherein each of the particles comprises a plurality of conductive fibers and the plurality of conductive fibers are in contact with one another.

53. The antenna of Claim 51, wherein each of the particles comprises a plurality of conductive fibers and the plurality of conductive fibers are not in contact with one another.

54. The antenna of Claim 51, wherein the vessel comprises an elastic material that is configured to expand and contract responsive to the force applied to the at least one end of the vessel.

55. The antenna of Claim 54, wherein the vessel is a first vessel and the lens further comprises:

a second vessel containing the dielectric and connected to the first vessel.

56. The antenna of Claim 55, wherein the second vessel comprises the elastic material that is configured to expand and contract responsive to the force applied to the at least one end of the vessel.

57. The antenna of Claim 55, wherein the radiating element is a first radiating element and the radio frequency signal pattern is a first radio frequency signal pattern, the antenna further comprising:

a second radiating element configured to generate a second radio frequency signal pattern;

wherein the first vessel is configured to receive the first radio frequency signal pattern therethrough; and

wherein the second vessel is configured to receive the second radio frequency signal pattern therethrough.

58. The antenna of Claim 54, wherein the lens further comprises an exo-skeleton having a plurality of openings formed therein, the vessel being carried within the exo- skeleton and being constrained by the exo-skeleton responsive to the force applied to the at least one end of the vessel.

59. The antenna of Claim 58, wherein the radiating element is a first radiating element and the radio frequency signal pattern is a first radio frequency signal pattern, the antenna further comprising:

a second radiating element configured to generate a second radio frequency signal pattern;

wherein a first portion of the vessel protruding from a first one of the plurality of openings in the exo-skeleton is configured to receive the first radio frequency signal pattern therethrough; and

wherein a second portion of the vessel protruding from a second one of the plurality of openings in the exo-skeleton is configured to receive the second radio frequency signal pattern therethrough.

60. The antenna of Claim 46, further comprising:

a force element;

a pressure regulator that connects the force element to a first one of the at least one end of the vessel;

a pressure relief valve connected to a second one of the at least one end of the vessel; a backpressure module; and

a check valve that connects the backpressure module to the pressure relief valve.

61. The antenna of Claim 60, wherein the pressure regulator comprises a proportional valve and the force element comprises a pressurized gas canister.

62. The antenna of Claim 46, wherein the volume of the vessel is adjustable to shape the radio frequency signal pattern.

63. The antenna of Claim 46, wherein the volume of the vessel is adjustable to tilt the radio frequency signal pattern.

64. The antenna of Claim 46, wherein the volume of the vessel is adjustable to change an operating frequency of the radio frequency signal pattern.

65. An electronic device, comprising: a lens configured to receive a radio frequency signal pattern therethrough, the lens comprising a vessel containing a dielectric comprising a composition of fluid and gas, the vessel having a volume that is adjustable responsive to force applied to at least one end of the vessel.

66. The electronic device of Claim 65, wherein the fluid comprises glycerin and the gas comprises air.

67. The electronic device of Claim 65, wherein the fluid comprises glycerin and the gas comprises an inert gas.

68. The electronic device of Claim 65, wherein the dielectric comprises dielectric particles.

69. The electronic device of Claim 65, wherein the vessel comprises an elastic material that is configured to expand and contract responsive to the force applied to the at least one end of the vessel.

70. The electronic device of Claim 69, wherein the vessel is a first vessel and the lens further comprises:

a second vessel containing the dielectric and connected to the first vessel.

71. The electronic device of Claim 69, wherein the second vessel comprises the elastic material that is configured to expand and contract responsive to the force applied to the at least one end of the vessel.

72. The electronic device of Claim 69, wherein the lens further comprises an exo- skeleton having a plurality of openings formed therein, the vessel being carried within the exo-skeleton and being constrained by the exo-skeleton responsive to the force applied to the at least one end of the vessel.

73. The electronic device of Claim 65, wherein the volume of the vessel is adjustable to shape the radio frequency signal pattern.

74. The electronic device of Claim 65, wherein the volume of the vessel is adjustable to tilt the radio frequency signal pattern.

75. The electronic device of Claim 65, wherein the volume of the vessel is adjustable to change an operating frequency of the radio frequency signal pattern.

76. An antenna, comprising:

a radiating element configured to generate a radio frequency signal pattern, the radiating element comprising a plurality of stacked conductive layers separated by dielectric layers, each of the conductive layers having a conductive pattern formed thereon, such that adjacent ones of the conductive patterns are coupled via a wired connection.

77. The antenna of Claim 76, wherein the radiating element is a first radiating element, the antenna further comprising:

a second radiating element that is not included in the stacked conductive layers and is connected to the first radiating element.

78. The antenna of Claim 76, wherein the wired connection is a radio frequency jumper.

79. The antenna of Claim 76, wherein portions of the conductive pattern on one of the conductive layers are not coupled to each other via the wired connection.

80. The antenna of Claim 76, wherein a first design of the conductive pattern on a first one of the plurality of stacked conductive layers is different from a second design of the conductive pattern on a second one of the plurality of stacked conductive layers.

81. The antenna of Claim 76, wherein a number of the plurality of stacked conductive layers is adjustable to shape the radio frequency signal pattern.

82. The antenna of Claim 76, wherein a number of the plurality of stacked conductive layers is adjustable to tilt the radio frequency signal pattern.

83. The antenna of Claim 76, wherein a number of the plurality of stacked conductive layers is adjustable to change an operating frequency of the radio frequency signal pattern.

84. The antenna of Claim 76, wherein a design of the conductive pattern on at least one of the plurality of stacked conductive layers is configured to shape the radio frequency signal pattern.

85. The antenna of Claim 76, wherein a design of the conductive pattern on at least one of the plurality of stacked conductive layers is configured to tilt the radio frequency signal pattern.

86. The antenna of Claim 76, wherein a design of the conductive pattern on at least one of the plurality of stacked conductive layers is configured to change an operating frequency of the radio frequency signal pattern.

87. The antenna of Claim 76, further comprising:

a frequency dependent divider circuit configured to receive an input signal and generate an output signal, the output signal having a power level based on a frequency of the input signal;

wherein the radiating element is responsive to the output signal.

88. The antenna of Claim 87, wherein the frequency dependent divider circuit comprises:

a power divider that is configured to generate a first divided output signal and a second divided output signal responsive to the input signal;

a delay element that is configured to generate a phase delayed output signal responsive to the second divided output signal, the phase delayed output signal having a phase delay based on a frequency of the second divided output signal; and

a directional coupler that is configured to generate the output signal responsive to the phase delayed output signal and the first divided output signal.

89. The antenna of Claim 88, further comprising: a stub circuit configured to generate first and second coupler input signals responsive to the phase delayed output signal and the first divided output signal;

wherein the directional coupler is configured to generate the output signal responsive to the first and second coupler input signals.

90. The antenna of Claim 89, wherein the stub circuit comprises a pair of quarter- wave shorted lines.

91. The antenna of Claim 89, wherein the stub circuit comprises a pair of half- wave open ended lines.

92. The antenna of Claims 89, wherein an input impedance of the stub circuit is capacitive.

93. The antenna of Claim 89, wherein an input impedance of the stub circuit is inductive.

94. The antenna of Claim 88, wherein the directional coupler is a 90° hybrid branch-line coupler having an operational bandwidth of approximately 690 MHz - 2700 MHz.

95. The antenna of Claim 88, wherein the power divider is a 3dB multi-section Wilkinson. power divider.

96. An antenna, comprising:

a frequency dependent divider circuit configured to receive an input signal and generate an output signal, the output signal having a power level based on a frequency of the input signal; and

a radiating element configured to generate a radio frequency signal pattern responsive to the output signal, the radiating element comprising a plurality of stacked conductive layers separated by dielectric layers, each of the conductive layers having a conductive pattern formed thereon, such that adjacent ones of the conductive patterns being coupled via a wired connection, and a number of the plurality of stacked conductive layers is adjustable to at least one of shape the radio frequency signal pattern, tilt the radio frequency signal pattern, and change an operating frequency of the radio frequency signal pattern.

97. The antenna of Claim 96, wherein the radiating element is a first radiating element, the antenna further comprising:

a second radiating element that is not included in the stacked conductive layers and is connected to the first radiating element.

98. The antenna of Claim 96, wherein the wired connection is a radio frequency jumper.

99. The antenna of Claim 96, wherein portions of the conductive pattern on one of the conductive layers are not coupled to each other via the wired connection.

100. The antenna of Claim 96, wherein a first design of the conductive pattern on a first one of the plurality of stacked conductive layers is different from a second design of the conductive pattern on a second one of the plurality of stacked conductive layers.

101. An antenna, comprising:

a frequency dependent divider circuit configured to receive an input signal and generate an output signal, the output signal having a power level based on a frequency of the input signal; and

a radiating element configured to generate a radio frequency signal pattern responsive to the output signal, the radiating element comprising a plurality of stacked conductive layers separated by dielectric layers, each of the conductive layers having a conductive pattern formed thereon, such that adjacent ones of the conductive patterns being coupled via a wired connection, and a design of the conductive pattern on at least one of the plurality of stacked conductive layers is configured to at least one of shape the radio frequency signal pattern, tilt the radio frequency signal pattern, and change an operating frequency of the radio frequency signal pattern.

102. The antenna of Claim 101, wherein the radiating element is a first radiating element, the antenna further comprising: a second radiating element that is not included in the stacked conductive layers and is connected to the first radiating element.

103. The antenna of Claim 101, wherein the wired connection is a radio frequency jumper.

104. The antenna of Claim 101, wherein portions of the conductive pattern on one of the conductive layers are not coupled to each other via the wired connection.

105. The antenna of Claim 101, wherein a first design of the conductive pattern on a first one of the plurality of stacked conductive layers is different from a second design of the conductive pattern on a second one of the plurality of stacked conductive layers.

Description:
ANTENNA SYSTEMS WITH ADJUSTABLE PHASE DELAY ELEMENTS HAVING CONFIGURABLE DIELECTRIC COMPOSITIONS

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U.S. Provisional Patent Application Serial No. 62/647,957, filed March 26, 2018, U.S. Provisional Patent Application Serial No.

62/647,990, filed March 26, 2018, and U.S. Provisional Patent Application Serial No.

62/648,003, filed March 26, 2018 the entire content of each of these applications is incorporated by reference herein as if set forth in its entirety.

FIELD OF THE INVENTION

[0002] The present disclosure relates generally to radio communications and, more particularly, to multi-beam antennas used in cellular communications systems.

BACKGROUND

[0003] Wireless base stations are well known in the art and typically include, among other things, baseband equipment, radios and antennas. The antennas are often mounted at the top of a tower or other elevated structure, such as a pole, a rooftop, water towers or the like. Typically, multiple antennas are mounted on the tower, and a separate baseband unit and radio are connected to each antenna. Each antenna provides cellular service to a defined coverage area or "sector."

[0004] FIG. 1 is a simplified, schematic diagram that illustrates a conventional cellular base station 10. As shown in FIG. 1, the cellular base station 10 includes an antenna tower 30 and an equipment enclosure 20 that is located at the base of the antenna tower 30. A plurality of baseband units 22 and radios 24 are located within the equipment enclosure 20. Each baseband unit 22 is connected to a respective one of the radios 24 and is also in

communication with a backhaul communications system 44. Three sectorized antennas 32 (labelled antennas 32-1, 32-2, 32-3) are located at the top of the antenna tower 30. Three coaxial cables 34 (which are bundled together in FIG. 1 to appear as a single cable) connect the radios 24 to the respective antennas 32. Each end of each coaxial cable 34 may be connected to a duplexer (not shown) so that both the transmit and receive signals for each radio 24 may be carried on a single coaxial cable 34. In some implementations the radios 24 are located at the top of the tower 30 instead of in the equipment enclosure 20 to reduce signal transmission losses. [0005] Cellular base stations typically use directional antennas 32 such as phased array antennas to provide increased antenna gain throughout a defined coverage area. A typical phased array antenna 32 may be implemented as a planar array of radiating elements mounted on a panel, with perhaps ten radiating elements per panel. Typically, each radiating element is used to (1) transmit radio frequency ("RF") signals that are received from a transmit port of an associated radio 24 and (2) receive RF signals from mobile users and pass such received signals to the receive port of the associated radio 24. Duplexers are typically used to connect the radio 24 to each respective radiating element of the antenna 32. A "duplexer" refers to a well-known type of three-port filter assembly that is used to connect both the transmit and receive ports of a radio 24 to an antenna 32 or to a radiating element of a multi-element antenna 32. Duplexers are used to isolate the RF transmission paths to the transmit and receive ports of the radio 24 from each other while allowing both RF transmission paths access to the radiating elements of the antenna 32, and may accomplish this even though the transmit and receive frequency bands may be closely spaced together.

[0006] To transmit RF signals to, and receive RF signals from, a defined coverage area, each directional antenna 32 is typically mounted to face in a specific direction (referred to as "azimuth") relative to a reference such as true north, to be inclined at a specific angle with respect to the horizontal in the plane of the azimuth (referred to as "elevation" or "tilt"), and to be vertically aligned with respect to the horizontal (referred to as "roll").

[0007] FIG. 2A is a perspective view of a lensed multi-beam base station antenna 200 that can be used to implement the directional antennas 32 of FIG. 1. FIG. 2B is a cross-sectional view of the lensed multi-beam base station antenna 200. The lensed multi-beam base station antenna 200 is described in detail in U.S. Patent Publication No. 2015/0091767, the disclosure of which is hereby incorporated herein by reference.

[0008] Referring to FIGS. 2 A and 2B, the multi-beam base station antenna 200 includes one or more linear arrays of radiating elements 210A, 210B, and 210C (referred to herein collectively using reference numeral 210). These linear arrays of radiating elements 210 are also referred to as "linear arrays" or "arrays" herein. The antenna 200 further includes an RF lens 230. Each linear array 210 may have approximately the same length as the lens 230.

The multi-beam base station antenna 200 may also include one or more of a secondary lens 240 (see FIG. 2B), a reflector 250, a radome 260, end caps 270, a tray 280 (see FIG. 2B) and input/output ports 290. In the description that follows, the azimuth plane is perpendicular to the longitudinal axis of the RF lens 230, and the elevation plane is parallel to the longitudinal axis of the RF lens 230. [0009] The RF lens 230 is used to focus the radiation coverage pattern or "beam" of the linear arrays 210 in the azimuth direction. For example, the RF lens 230 may shrink the 3 dB beam widths of the beams (labeled BEAM1, BEAM2 and BEAM 3 in FIG. 2B) output by each linear array 210 from about 65° to about 23° in the azimuth plane. While the antenna 200 includes three linear arrays 210, different numbers of linear arrays 210 may be used.

[0010] Each linear array 210 includes a plurality of radiating elements 212. Each radiating element 212 may comprise, for example, a dipole, a patch or any other appropriate radiating element. Each radiating element 212 may be implemented as a pair of cross-polarized radiating elements, where one radiating element of the pair radiates RF energy with a +45° polarization and the other radiating element of the pair radiates RF energy with a -45° polarization.

[0011] The RF lens 230 narrows the half power beam width ("HPBW") of each of the linear arrays 210 while increasing the gain of the beam by, for example, about 4-5 dB for the 3- beam multi -beam antenna 200 depicted in FIGS. 2 A and 2B. All three linear arrays 210 share the same RF lens 230, and, thus, each linear array 210 has its HPBW altered in the same manner. The longitudinal axes of the linear arrays 210 of radiating elements 212 can be parallel with the longitudinal axis of the lens 230. In other embodiments, the axis of the linear arrays 210 can be slightly tilted (2-10°) to the axis of the lens 230 (for example, for better return loss or port-to-port isolation tuning).

[0012] The multi-beam base station antenna 200 may be used to increase system capacity. For example, a conventional 65° azimuth HPBW antenna could be replaced with the multi- beam base station antenna 200 as described above. This would increase the traffic handling capacity for the base station 10, as each beam would have 4-5 dB higher gain and hence could support higher data rates at the same quality of service. In another example, the multi- beam base station antenna 200 may be used to reduce antenna count at a tower or other mounting location. The three beams (BEAM 1, BEAM 2, BEAM 3) generated by the antenna 200 are shown schematically in FIG. 2B. The azimuth angle for each beam may be approximately perpendicular to the reflector 250 for each of the linear arrays 210. In the depicted embodiment the -10 dB beam width for each of the three beams is approximately 40° and the center of each beam is pointed at azimuth angles of -40°, 0°, and 40°, respectively. Thus, the three beams together provide 120° coverage.

[0013] The RF lens 230 may be formed of a dielectric lens material 232. The RF lens 230 may include a shell, such as a hollow, lightweight structure that holds the dielectric material 232. The dielectric lens material 232 focuses the RF energy that radiates from, and is received by, the linear arrays 210.

SUMMARY

[0014] In some embodiments of the inventive concept, an antenna comprises a delay element that is configured to generate a phase delayed output signal responsive to an input signal, the phase delayed output signal having a phase delay based on a frequency of the input signal, the delay element comprising: a variable capacitor comprising a conductive line element and a ground plane element separated by a vessel containing a dielectric, the dielectric comprising a composition of fluid and gas in proportions that are adjustable responsive to forces applied at opposing ends of the vessel, respectively. A radiating element is responsive to the phase delayed output signal.

[0015] In other embodiments, the antenna further comprises a power divider that is configured to generate a first divided output signal and a second divided output signal responsive to the input signal. The delay element is configured to generate the phase delayed output signal responsive to the second divided output signal, the phase delayed output signal having the phase delay based on a frequency of the second divided output signal.

[0016] In still other embodiments, the antenna further comprises a directional coupler that is configured to generate the output signal responsive to the phase delayed output signal and the first divided output signal.

[0017] In still other embodiments, the directional coupler is a 90° hybrid branch-line coupler having an operational bandwidth within a range of approximately 690 MHz - 2700 MHz.

[0018] In still other embodiments, the antenna further comprises a stub circuit configured to generate first and second coupler input signals responsive to the phase delayed output signal and the first divided output signal. The directional coupler is configured to generate the output signal responsive to the first and second coupler input signals.

[0019] In still other embodiments, the stub circuit comprises a pair of quarter-wave shorted lines.

[0020] In still other embodiments, the stub circuit comprises a pair of half-wave open ended lines.

[0021] In still other embodiments, an input impedance of the stub circuit is capacitive.

[0022] In still other embodiments, an input impedance of the stub circuit is inductive.

[0023] In still other embodiments, the fluid comprises glycerin and the gas comprises air. [0024] In still other embodiments, the fluid comprises glycerin and the gas comprises an inert gas.

[0025] In still other embodiments, the antenna further comprises a processing unit that is configured to determine a volume of the gas in the vessel based on a temperature

measurement and a pressure measurement of the gas.

[0026] In still other embodiments, the antenna further comprises an optical sensor that is configured to determine the proportions of the fluid and gas, respectively, in the vessel.

[0027] In still other embodiments, the antenna further comprises a float switch that is configured to determine the proportions of the fluid and gas, respectively, in the vessel.

[0028] In still other embodiments, the antenna further comprises first and second force elements and first and second pressure regulators that connect the first and second force elements to the opposing ends of the vessel, respectively.

[0029] In still other embodiments, the first and second force elements comprise first and second pressurized gas canisters, respectively. The first and second pressure regulators comprise first and second proportional valves, respectively.

[0030] In still other embodiments, the ground plane element is a first ground plane element and the variable capacitor further comprises: a second ground plane element, the conductive line element being spaced apart from the first ground plane element by the dielectric in a first portion of the vessel and being spaced apart from the second ground plane element by the dielectric in a second portion of the vessel.

[0031] In still other embodiments, the antenna further comprises a force element, a force distribution manifold connected to the force element, and first and second pressure regulators that connect the force distribution manifold to the opposing ends of the vessel, respectively.

[0032] In still other embodiments, the force element comprises a pressurized gas canister. The first and second pressure regulators comprise first and second proportional valves, respectively.

[0033] In still other embodiments, the vessel is oriented so that gravitational force at least partially resists entry of the fluid into the vessel.

[0034] In still other embodiments, the antenna further comprises a fluid pump connected to a first one of the opposing ends of the vessel and a flow control orifice connected to a second one of the opposing ends of the vessel.

[0035] In still other embodiments, the antenna further comprises a ball type pressure relief valve connected to the flow control orifice. [0036] In still other embodiments, the antenna further comprises a piston type pressure relief valve connected to the flow control orifice.

[0037] In still other embodiments, the antenna further comprises a fluid pump connected to a first one of the opposing ends of the vessel, a pressure regulator connected to a second one of the opposing ends of the vessel, and a force element connected to the second one of the opposing ends of the vessel.

[0038] In still other embodiments, the pressure regulator comprises a proportional valve and the force element comprises a pressurized gas canister.

[0039] In still other embodiments, the ground plane element is a first ground plane element, the vessel is a first vessel, and the dielectric is a first dielectric, the variable capacitor further comprising: a second ground plane element, the conductive line element being spaced apart from the first ground plane element by the first dielectric in the first vessel and being spaced apart from the second ground plane element by the second dielectric in the second vessel.

[0040] In still other embodiments, the antenna further comprises a force element, a force distribution manifold connected to the force element, first and second pressure regulators that connect the force distribution manifold to the opposing ends of the first vessel, respectively, and third and fourth pressure regulators that connect the force distribution manifold to opposing ends of the second vessel, respectively.

[0041] In still other embodiments, the force element comprises a pressurized gas canister. The first, second, third, and fourth pressure regulators comprise first, second, third, and fourth proportional valves, respectively.

[0042] In still other embodiments, the vessel comprises an elastic material that is configured to expand and contract responsive the forces applied at the opposing ends of the vessel.

[0043] In some embodiments of the inventive concept, an antenna comprises a radiating element configured to generate a radio frequency signal pattern and a lens configured to receive the radio frequency signal pattern therethrough. The lens comprises a vessel containing a dielectric comprising a composition of fluid and gas, the vessel having a volume that is adjustable responsive to force applied to at least one end of the vessel.

[0044] In other embodiments, the fluid comprises glycerin and the gas comprises air.

[0045] In still other embodiments, the fluid comprises glycerin and the gas comprises an inert gas.

[0046] In still other embodiments, the dielectric comprises dielectric particles.

[0047] In still other embodiments, each of the dielectric particles has a density in a range from about 0.005 to about 0.1 g/cm . [0048] In still other embodiments, each of the particles comprises at least one conductive fiber.

[0049] In still other embodiments, each of the particles comprises a plurality of conductive fibers and the plurality of conductive fibers are in contact with one another.

[0050] In still other embodiments, each of the particles comprises a plurality of conductive fibers and the plurality of conductive fibers are not in contact with one another.

[0051] In still other embodiments, the vessel comprises an elastic material that is configured to expand and contract responsive to the force applied to the at least one end of the vessel.

[0052] In still other embodiments, the vessel is a first vessel and the lens further comprises a second vessel containing the dielectric and connected to the first vessel.

[0053] In still other embodiments, the second vessel comprises the elastic material that is configured to expand and contract responsive to the force applied to the at least one end of the vessel.

[0054] In still other embodiments, the radiating element is a first radiating element and the radio frequency signal pattern is a first radio frequency signal pattern. The antenna further comprises a second radiating element configured to generate a second radio frequency signal pattern. The first vessel is configured to receive the first radio frequency signal pattern therethrough. The second vessel is configured to receive the second radio frequency signal pattern therethrough.

[0055] In still other embodiments, the lens further comprises an exo-skeleton having a plurality of openings formed therein, the vessel being carried within the exo-skeleton and being constrained by the exo-skeleton responsive to the force applied to the at least one end of the vessel.

[0056] In still other embodiments, the radiating element is a first radiating element and the radio frequency signal pattern is a first radio frequency signal pattern. The antenna further comprises a second radiating element configured to generate a second radio frequency signal pattern. A first portion of the vessel protruding from a first one of the plurality of openings in the exo-skeleton is configured to receive the first radio frequency signal pattern therethrough. A second portion of the vessel protruding from a second one of the plurality of openings in the exo-skeleton is configured to receive the second radio frequency signal pattern therethrough.

[0057] In still other embodiments, the antenna further comprises a force element, a pressure regulator that connects the force element to a first one of the at least one end of the vessel, a pressure relief valve connected to a second one of the at least one end of the vessel, a backpressure module, and a check valve that connects the backpressure module to the pressure relief valve.

[0058] In still other embodiments, the pressure regulator comprises a proportional valve and the force element comprises a pressurized gas canister.

[0059] In still other embodiments, the volume of the vessel is adjustable to shape the radio frequency signal pattern.

[0060] In still other embodiments, the volume of the vessel is adjustable to tilt the radio frequency signal pattern.

[0061] In still other embodiments, the volume of the vessel is adjustable to change an operating frequency of the radio frequency signal pattern.

[0062] In some embodiments of the inventive concept, an antenna comprises a radiating element configured to generate a radio frequency signal pattern, the radiating element comprising a plurality of stacked conductive layers separated by dielectric layers, each of the conductive layers having a conductive pattern formed thereon, such that adjacent ones of the conductive patterns are coupled via a wired connection.

[0063] In other embodiments, the radiating element is a first radiating element and the antenna further comprises a second radiating element that is not included in the stacked conductive layers and is connected to the first radiating element.

[0064] In still other embodiments, wherein the wired connection is a radio frequency jumper.

[0065] In still other embodiments, wherein portions of the conductive pattern on one of the conductive layers are not coupled to each other via the wired connection.

[0066] In still other embodiments, a first design of the conductive pattern on a first one of the plurality of stacked conductive layers is different from a second design of the conductive pattern on a second one of the plurality of stacked conductive layers.

[0067] In still other embodiments, a number of the plurality of stacked conductive layers is adjustable to shape the radio frequency signal pattern.

[0068] In still other embodiments, a number of the plurality of stacked conductive layers is adjustable to tilt the radio frequency signal pattern.

[0069] In still other embodiments, a number of the plurality of stacked conductive layers is adjustable to change an operating frequency of the radio frequency signal pattern.

[0070] In still other embodiments, a design of the conductive pattern on at least one of the plurality of stacked conductive layers is configured to shape the radio frequency signal pattern. [0071] In still other embodiments, a design of the conductive pattern on at least one of the plurality of stacked conductive layers is configured to tilt the radio frequency signal pattern.

[0072] In still other embodiments, a design of the conductive pattern on at least one of the plurality of stacked conductive layers is configured to change an operating frequency of the radio frequency signal pattern.

[0073] In still other embodiments, the antenna further comprises a frequency dependent divider circuit configured to receive an input signal and generate an output signal, the output signal having a power level based on a frequency of the input signal. Thee radiating element is responsive to the first output signal.

[0074] In still other embodiments, the frequency dependent divider circuit comprises: a power divider that is configured to generate a first divided output signal and a second divided output signal responsive to the input signal, a delay element that is configured to generate a phase delayed output signal responsive to the second divided output signal, the phase delayed output signal having a phase delay based on a frequency of the second divided output signal; and a directional coupler that is configured to generate the output signal responsive to the phase delayed output signal and the first divided output signal.

[0075] In still other embodiments, the antenna further comprises a stub circuit configured to generate first and second coupler input signals responsive to the phase delayed output signal and the first divided output signal. The directional coupler is configured to generate the output signal responsive to the first and second coupler input signals.

[0076] ln still other embodiments, the stub circuit comprises a pair of quarter-wave shorted lines.

[0077] In still other embodiments, the stub circuit comprises a pair of half-wave open ended lines.

[0078] In still other embodiments, an input impedance of the stub circuit is capacitive.

[0079] In still other embodiments, an input impedance of the stub circuit is inductive.

[0080] In still other embodiments, the directional coupler is a 90° hybrid branch-line coupler having an operational bandwidth of approximately 690 MHz - 2700 MHz.

[0081] In still other embodiments, the power divider is a 3dB multi-section Wilkinson power divider.

[0082] It is noted that aspects described with respect to one embodiment may be

incorporated in different embodiments although not specifically described relative thereto. That is, all embodiments and/or features of any embodiments can be combined in any way and/or combination. Moreover, other apparatus, methods, systems, and/or articles of manufacture according to embodiments of the inventive subject matter will be or become apparent to one with skill in the art upon review of the following drawings and detailed description. It is intended that all such additional apparatus, systems, methods, and/or articles of manufacture be included within this description, be within the scope of the present inventive subject matter, and be protected by the accompanying claims. It is further intended that all embodiments disclosed herein can be implemented separately or combined in any way and/or combination.

BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Other features of embodiments will be more readily understood from the following detailed description of specific embodiments thereof when read in conjunction with the accompanying drawings, in which:

[0084] FIG. 1 is a simplified, schematic diagram that illustrates a conventional cellular base station;

[0085] FIG. 2A is a perspective view of a lensed multi-beam base station antenna that can be used to implement the directional antenna of FIG. 1 ;

[0086] FIG. 2B is a cross-sectional view of the lensed multi-beam base station antenna of FIG. 2A;

[0087] FIG. 3 is a block diagram of a frequency dependent power divider circuit according to some embodiments of the inventive concept;

[0088] FIG. 4 is a table that illustrates operations of the frequency dependent power divider circuit of FIG. 3 according to some embodiments of the inventive concept;

[0089] FIG. 5 is a schematic of an antenna system including a frequency dependent power divider circuit according to some embodiments of the inventive concept;

[0090] FIG. 6 is a block diagram of a frequency dependent power divider circuit including a stub circuit according to some embodiments of the inventive concept;

[0091] FIGS. 7 A - 7H are diagrams of adjustable phase delay elements having configurable dielectric compositions according to some embodiments of the inventive concept;

[0092] FIG. 8 is a diagram of an elastic vessel for holding a dielectric according to some embodiments of the inventive concept;

[0093] FIGS. 9 A and 9B are diagrams illustrating the elastic vessel of FIG. 8 used in a Radio Frequency (RF) lens according to some embodiments of the inventive concept;

[0094] FIGS. 9C and 9D are plan views of exo-skeletons for use in shaping the elastic vessel of FIG. 8 according to some embodiments of the inventive concept; [0095] FIG. 10 is a multi-layer radiating element for use in an antenna structure according to some embodiments of the inventive concept; and

[0096] FIGS. 11 A - 11D are plan views of conductive patterns for use in the multi-layer radiating element of FIG. 10 according to some embodiments of the inventive concept.

DETAILED DESCRIPTION

[0097] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments of the present disclosure. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In some instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present disclosure. It is intended that all embodiments disclosed herein can be implemented separately or combined in any way and/or combination. Aspects described with respect to one embodiment may be incorporated in different embodiments although not specifically described relative thereto. That is, all embodiments and/or features of any embodiments can be combined in any way and/or combination.

[0098] Some embodiments of the inventive concept stem from a realization that a frequency dependent power divider circuit may be used between, for example, a beam forming network and a radiating element. Such frequency dependent power divider circuits may use a delay element to direct signal power to specific radiating elements based on signal frequency. In some embodiments of the inventive concept, adjustable delay elements are provided that are based on one or more variable capacitors where the permittivity of the dielectric layer may be changed to vary the capacitance.

[0099] Other embodiments of the inventive concept stem from a realization that wireless communication networks are evolving to support increasing numbers of sectors via a single base station. Increasing the number of sectors increases system capacity because each antenna beam can service a smaller area. Dividing a coverage area into smaller sectors, however, typically involves the use of more radiating elements that are spaced wider than antennas covering wider sectors. This may increase the cost and space requirements for supporting cells that are divided into greater numbers of sectors. Antennas have been developed using multi-beam forming networks driving arrays of radiating elements. These radiating element arrays may be coupled with a lens system to direct the output beams for improved sector coverage. Embodiments of the inventive concept provide an elastic lens with an adjustable volume for holding a dielectric, which can be used to provide improved beam shaping, tilting, and/or frequency variation/shifting for RF beams output from one or more radiating elements of an antenna.

[00100] Further embodiments of the inventive concept stem from a realization that wireless communication networks are evolving to support increasing numbers of sectors via a single base station. Increasing the number of sectors increases system capacity because each antenna can service a smaller area. Dividing a coverage area into smaller sectors, however, typically involves the use of more radiating elements that are spaced wider than antennas covering wider sectors. This may increase the cost and space requirements for supporting cells that are divided into greater numbers of sectors. Antennas have been developed using multi-beam forming networks driving arrays of radiating elements. Embodiments of the inventive concept may provide radiating elements including multiple layers that may be configured with conductive pattern designs to improve beam shaping, tilting, and/or frequency variation/shifting for RF beams output from one or more radiating elements of an antenna.

[00101] FIG. 3 is a block diagram of a frequency dependent power divider circuit 300 according to some embodiments of the inventive concept. The frequency dependent power divider circuit 300 comprises a power divider 305 having a first output that is coupled to a first input of a directional coupler 315. A second output of the power divider 305 is coupled to a second input of the directional coupler 315 via a delay element 310. The power divider 305 splits the signal from the beam forming network into two signals. The power divider 305 may divide the power approximately equally between its two output terminals. The delay element 310 imposes a phase delay to the signal received from the power divider 305 and provides this phase delayed signal as an input signal to the directional coupler 315. The delay element 310 may have a fixed length and an electrical reactance associated therewith, which results in the phase delay applied to the signal output from the power divider 305 to vary with frequency. In some embodiments, the delay element may be configured so as for a given time delay, higher frequency signals experience more phase delay than low frequency signals. The directional coupler 315 receives equal amplitude signals as input signals where the signal received from the delay element 310 may experience increasing phase delay with increasing frequency based on the configuration of the delay element 310. The directional coupler 315 outputs equal phase, variable amplitude signals where the amount of amplitude difference depends on the phase delay between the inputs, where, in some embodiments, the phase delay increases with increasing frequency. In accordance with some embodiments of the inventive concept, the directional coupler 315 may be 90° hybrid branch-line coupler with an operable bandwidth of approximately 690 MHz - 2700 MHz. The power divider 305 may be, for example, a 3dB multi-section Wilkinson power divider.

[00102] FIG. 4 is a table that illustrates operations of the frequency dependent power divider circuit 300 of FIG. 3 according to some embodiments of the inventive concept. When the delay element 310 provides a phase delay f of 0°, then the signal power at output terminals A and B of the directional coupler 315 is split approximately evenly with each terminal receiving 1/2 the output power. When the delay element 310 provides a phase delay f of 90°, then the signal power is directed approximately in its entirety to terminal A with terminal B receiving approximately zero signal power. When the delay element 310 provides a phase delay f of -90°, then the signal power is directed approximately in its entirety to terminal B with terminal A receiving approximately zero signal power.

[00103] Some governmental jurisdictions place limits on antenna gain at one or more frequencies. The frequency dependent power divider circuit 300 of FIG. 3 may be configured to divert power towards one of the output terminals A or B at a frequency at which transmitted signal power is to be reduced and may be configured to divert power towards another one of the output terminals A or B at a frequency at which transmitted signal power is to be maintained. Embodiments of the inventive concept may be illustrated by way of example. A communication system may operate by transmitting in frequency bands 1710 MHz - 1880 MHz, 1910 MHz - 2170 MHz, and 2496 MHz - 2690 MHz. A governmental regulation may limit the antenna gain at 2560 MHz to a threshold of no more than 17.0 dB. Thus, it may be desirable to reduce the gain at 2560 MHz without adversely impacting the gain in the other frequency bands of 1710 MHz - 1880 MHz and 1910 MHz - 2170 MHz. Using a frequency of 1940 MHz, which is at the center of the bands 1710 MHz - 1880 MHz and 1910 MHz - 2170 MHz, the frequency dependent power divider circuit 300 can be tuned so that the delay element 310 generates a phase delay f of approximately -90° at 1940 MHz, this results in approximately all of the signal power being diverted to terminal B. When delay element 310 is configured to generate a phase delay f of approximately -90° at 1940 MHz, then the following phase delays may be generated at frequencies 1750 MHz, 2170 MHz, and 2560 MHz:

[00104] f = -116° at 1750 MHz

[00105] f = -57° at 2170 MHz

[00106] f = -4° at 2560 MHz

[00107] Thus, at 2560 MHz, the frequency dependent power divider circuit 300 divides the signal power approximately equally between terminals A and B. The frequency dependent power divider circuit 300 can be used in an antenna system to adjust the signal power directed to a radiating element to ensure the antenna gain does not exceed a defined threshold as will be described below with reference to FIG. 5.

[00108] FIG. 5 is a schematic of an antenna system 500 including a frequency dependent power divider circuit 510 according to some embodiments of the inventive concept. The antenna system 500 comprises a beam forming network (BFN) that receives a beam and distributes the signal to six different radiating elements 515A, 515B, 515C, 515D, 515E, and 515F. Each of these radiating elements 515A, 515B, 515C, 515D, 515E, and 515F may represent an entire antenna, a linear array of radiating elements that comprises part of an antenna, and/or a single radiating element that is part of a larger array of radiating elements in accordance with various embodiments of the inventive concept. As shown in FIG. 5, frequency dependent power divider circuits 510A, 510B, and 510C are used as an interface to the radiating elements 515 A, 515B, 515C, 515D, 515E, and 515F. Specifically, the frequency dependent power divider circuit 510A receives an output signal from the BFN 505 and diverts a portion of the signal power through terminal A to the radiating element 515A and another portion of the signal power through terminal B to the radiating element 515B. Similarly, frequency dependent power divider circuit 510B receives an output signal from the BFN 505 and diverts a portion of the signal power through terminal A to the radiating element 515C and another portion of the signal power through terminal B to the radiating element 515D. Frequency dependent power divider circuit 510C receives an output signal from the BFN 505 and diverts a portion of the signal power through terminal A to the radiating element 515E and another portion of the signal power through terminal B to the radiating element 515F. The frequency dependent power divider circuit 510 may be implemented using the frequency dependent power divider circuit 300 of FIG. 3. The RF lens 520 may be used to focus the radiation coverage pattern or "beams" of the radiating elements 515 A, 515B, 515C, 515D, 515E, and 515F in the azimuth direction. In some embodiments, the RF lens 520 may be configured as one or more elastic vessels containing a dielectric material. The RF lens 520 may be dynamically configured to generate a desired radiation coverage pattern based on the shape(s) of the one or more elastic vessels, the dielectric material contained in the elastic vessel(s), and/or the presence of conductive particles within the dielectric in accordance with various embodiments of the inventive concept.

[00109] Applying the example described above to the example antenna system 500 of FIG.

5, the frequency dependent power divider circuits 510A, 510B, and 510C may divert signal power away from certain ones of the radiating elements 515A, 515B, 515C, 515D, 515E, and 515F and to other ones of the radiating elements 515A, 515B, 515C, 515D, 515E, and 515F. In other embodiments, a frequency dependent power divider may be configured to divert power between a radiating element and a diversion path, such as to ground through a resistor or other impedance element. This may reduce the gain of the antenna system 500 by reducing the energy directed to one or more radiating elements 515A, 515B, 515C, 515D, 515E, and 515F. The reduced energy results in an increase in the taper of the aperture of the signal driving particular ones of the radiating elements 515A, 515B, 515C, 515D, 515E, and 515F. The energy diverted to ground, for example, may represent an increase in the insertion loss of the antenna.

[00110] In the present example, it is generally desired to avoid decreasing the gain in the 1710 MHz - 1880 MHz and 1910 MHz - 2170 MHz frequency bands. The phase delay f at 1750 MHz is approximately -116° and the phase delay f at 2170 MHz is approximately -57°. As shown in FIG. 4, when the phase delay f is -90°, then virtually all of the signal power is directed to output terminal B of the frequency dependent power divider circuit 510. Because the phase delay f in the desired frequency ranges is not precisely -90°, the frequency dependent power divider circuits 510A. 510B, and 510C divert some of the signal power to through terminal A. To reduce the impact of power attenuation in the desired frequency bands, the frequency dependent power divider circuits 300 and 510A. 510B, and 510C may incorporate a stub circuit as described below with respect to FIG. 6.

[00111] FIG. 6 is a block diagram of a frequency dependent power divider circuit 600 including a stub circuit 620 according to some embodiments of the inventive concept. The frequency dependent power divider circuit 600 comprises a power divider 605, a delay element 610, and a directional coupler 615 that are configured as shown and may be implemented as described above with respect to corresponding elements in FIG. 3. The frequency dependent power divider circuit 600 differs from the frequency dependent power divider circuit 300 with the addition of a stub circuit 620 between the delay element 610 and the directional coupler 615 and the power divider 605 and the directional coupler 615. The stub circuit 620 may include one or more stubs or resonant stubs connected to the

transmission lines input to the directional coupler 615. A stub or resonant stub is a length of transmission line or waveguide that is connected at one end only. The free end of the stub is either left as an open-circuit or is short circuited to a reference terminal or plane. The input impedance of the stub is reactive— either capacitive or inductive— depending on the electrical length of the stub and whether it is configured as an open or short circuit. A stub may function as a capacitor, inductor, and/or a resonant circuit at radio frequencies. The stub circuit may provide, for example, phase compensation stubs to drive the phase delay f closer to -90° to allow more of the energy to be diverted to terminal B of the directional coupler 615. In some embodiments, two quarter- wave shorted lines may be used as the compensation stubs to compensate 90° and/or two half-wave open ended lines may be used as the compensation stubs to compensate 180°. Thus, in some embodiments, one or more of the frequency dependent power divider circuits 510A, 510B, and 510C of FIG. 5 may be implemented using the frequency dependent power divider circuit 600 of FIG. 6 to increase the power diverted to one or more of the radiating elements 515B, 515D, and 515F of FIG. 5 through terminal B of the directional coupler 615 to reduce the amount of gain reduction for the antenna system 500 in particular frequency bands, such as the 1710 MHz - 1880 MHz and 1910 MHz - 2170 MHz frequency bands.

[00112] The delay element 310 of FIG. 3 and the delay element 610 of FIG. 6 may be implemented in different ways according to various embodiments of the inventive concept. FIGS. 7A - 7H are diagrams of adjustable phase delay elements having configurable dielectric compositions that may be used to implement the delay element 310 and/or the delay element 610 according to some embodiments of the inventive concept. FIG. 7A illustrates an adjustable delay element 700A that includes a vessel 710 that is configured to hold a dielectric 715 comprising a fluid and gas mixture. The dielectric 715 separates a conductive trace line 720 from a ground plane 725 to form a capacitor. Capacitors are a well known passive electronic circuit element that may be used to store an electric charge. A capacitor may comprise a pair of electrical conductors that are referred to as electrodes that are separated by a dielectric material (e.g., an insulator that can be polarized). Most typically, each electrode may be implemented as a flat plate-shaped structure, although other-shaped electrodes may be used (e.g., annular cylinder electrodes). The example of FIG. 7A, the trace line 720 and ground plane 725 may serve as electrodes.

[00113] When a potential difference (V) is applied across the electrodes of a capacitor, an electric field develops across the dielectric material, causing positive charge to develop on one electrode and negative charge to develop on the other electrode. A capacitor is characterized by its capacitance (C), which is defined as the ratio of the electric charge on each electrode to the potential difference V between them. Capacitance is typically measured in farads.

[00114] The capacitance (C) of a capacitor may be expressed as follows:

[00115] C = * A/d (1) [00116] where:

[00117] e = the absolute permittivity of the dielectric layer (e.g., dielectric 715);

[00118] A = the area that the electrodes overlap in square meters (e.g., overlap between the conductive trace line 720 and the ground plane 725); and

[00119] d = the distance between the electrodes in meters (e.g., distance between the conductive trace line 720 and the ground plane 725).

[00120] The capacitance C of a capacitor may be changed by (1) changing the permittivity of the dielectric layer (e.g., dielectric layer 715), (2) changing the area of overlap of the electrodes (e.g., the area of overlap between the conductive trace line 720 and the ground plane 725) and/or (3) changing the distance between the electrodes (e.g., changing the distance between the conductive trace line 720 and the ground plane 725). Pursuant to some embodiments of the present inventive concept, adjustable delay elements may be provided that are based on one or more variable capacitors where the permittivity of the dielectric layer may be changed to vary the capacitance.

[00121] As shown in FIG. 7A, the permittivity of the dielectric layer 715 may be

dynamically configured based on the composition of the dielectric 715. Force elements 730A and 730B may generate force through access ports on opposing ends of the vessel 710 through pressure regulators 735 A and 735B, respectively. The differential in force applied to the fluid and gas components of the dielectric 715 applied at the opposing ends of the vessel 710 determines the relative composition of fluid and gas comprising the dielectric 715 between the conductive trace line 720 and the ground plane 725. The vessel 710 and lines connecting the vessel 710 to the force elements 730A and 730B, respectively, may be made of a generally inelastic material to avoid changing the volume of the vessel 710 in response to a force or pressure differential applied to the end ports of the vessel 710 and to instead change the composition of the dielectric 715 with respect to the ratio of fluid and gas comprising the dielectric 715. In accordance with various embodiments of the inventive concept, the fluid may comprise glycerin or other suitable fluid and the gas may comprise air and/or an inert gas, such as nitrogen. The force elements 730A and 730B may be embodied as pressurized gas canisters and the pressure regulators 735 A and 735B may be embodied as proportional valves.

[00122] The pressure regulators 735A and 735B may operate responsive to a dielectric feedback mechanism that provides information regarding the composition of the dielectric 715 with respect to the ratio of fluid and gas comprising the dielectric 715. In some embodiments, the feedback mechanism may comprise one or more of an optical sensor, a float switch, and processing unit that determines, for example, the volume of gas in the vessel 715 based on the principle of PV = nRT, where P is pressure of the gas, V is volume of the gas, n is the number of moles of the gas, R is the gas constant, and T is temperature. Where P, n, R, and T are known, the volume of the gas V can be determined. As the gas may expand and contract based on temperature, the pressure regulators 735 A and 735B may be configured to adjust the pressures applied to the opposing ends of the vessel 710 to maintain a desired dielectric 715 composition in response to changes in temperature.

[00123] FIG. 7B illustrates an adjustable delay element 700B that includes similar elements and has similar operations as those of the adjustable delay element 700A described above with respect to FIG. 7A. In contrast to the adjustable delay element 700A, the adjustable delay element 700B comprises two dielectrics 715 A and 715B contained in vessels 710A and 710B, respectively, that are used to form two separate capacitors in which the conductive trace line 720 forms a common electrode for both capacitors with the capacitors having separate ground planes 725 A and 725B, respectively. A single force element 730 is used to provide force or pressure at the opposing ends of both vessels 710A and 710B through the pressure regulators 735A, 735B, 735C, and 735D and a force distribution manifold 740.

Thus, as shown in FIG. 7B a dual capacitor configuration may be provided in which the force or pressure at each end of the vessels 710A and 710B may be individually controlled through use of only one force element 730 and a force distribution manifold 740. Although two vessels 710A and 710B are shown, it will be understood that in general a plurality of vessels may be arranged together and fed from the force distribution manifold 740.

[00124] FIG. 7C illustrates an adjustable delay element 700C that includes similar elements and has similar operations as those of the adjustable delay element 700B described above with respect to FIG. 7B. In contrast to the adjustable delay element 700B, the adjustable delay element 700C comprises a single dielectric 715 contained in a vessel 712 that is configured to form two separate capacitors in which the conductive trace line 720 forms a common electrode for both capacitors with the capacitors having separate ground planes 725A and 725B, respectively. A single force element 730 is used to provide force or pressure at the opposing ends of the vessel 712 through the pressure regulators 735A and 735B and a force distribution manifold 740. Thus, as shown in FIG. 7C a dual capacitor configuration may be provided in which a single vessel 712 is used having single ports at either end to control the fluid and gas composition of the dielectric 715 for both capacitors in common. [00125] FIG. 7D illustrates an adjustable delay element 700D that includes similar elements and has similar operations as those of the adjustable delay element 700C described above with respect to FIG. 7C. The adjustable delay element 700D differs from the adjustable delay element 700C in that the vessel 712 is oriented so that the force of gravity at least partially resists the entry of fluid into the vessel 712. Thus, as shown in FIG. 7D a dual capacitor configuration may be provided in which a single vessel 712 is used and the force of gravity is used to reduce the amount of force or pressure needed from the force element 730 to reduce the amount of fluid in the vessel 712 relative to the gas, which may extend the usable life of the force element 730 when the force element 730 is embodied, for example, as a pressurized gas canister.

[00126] FIG. 7E illustrates an adjustable delay element 700E that includes similar elements and has similar operations as those of the adjustable delay element 700D described above with respect to FIG. 7D. The adjustable delay element 700E differs from the adjustable delay element 700D in that the distribution manifold 740, pressure regulators 735 A and 735B, and force element 730 are eliminated and replaced with a fluid pump 732 that is used to pump fluid into the vessel 712 where the force of gravity at least partially resists the entry of fluid into the vessel 712. A flow control orifice 745 is disposed at the opposite end of the vessel 712 from the fluid pump 732 and provides a suitable amount of back pressure to prevent the gas from escaping the vessel 712.

[00127] FIGS. 7F - 7H illustrate adjustable delay elements 700F, 700G, and 700H that include similar elements and have similar operations as those of the adjustable delay element 700E described above with respect to FIG. 7E. The adjustable delay elements 700F and 700G differ from the adjustable delay element 700E in that pressure relief valves 750 A and 750B, respectively, are mounted to the flow control orifice 745 to provide additional backpressure and over pressure relief control. The relief valve 750A may be configured as a ball type or sphere type pressure relief valve in which the ball or sphere moves within a cylinder in response to pressure released through the flow control orifice 745. The relief valve 750B may be configured as a piston type pressure relief valve in which the piston moves within the cylinder in response to pressure released through the flow control orifice 745. The adjustable delay element 700H differs from the adjustable delay elements 700E, 700F, and 700G in that the flow control orifice 745 and pressure relief valves 750A and 750B are replaced with a pressure regulator 735, such as a proportional valve, and a force element 730, such as a pressurized gas canister to provide sufficient backpressure and over pressure relief control. [00128] As described above, the vessels 710 and 712 may be made of a generally inelastic material to avoid changing the volume of the vessels 710 and 712 in response to a force or pressure differential applied to the end ports of the vessels 710 and 712 and to instead change the composition of the dielectric 715 with respect to the ratio of fluid and gas comprising the dielectric 715. In other embodiments, the vessels 710 and 712 may be made from an elastic material designed to expand in response to pressure resulting from either one or more force elements 730 or, for example, increasing temperature. FIG. 8 is a diagram of an elastic vessel 810 for holding a dielectric according to some embodiments of the inventive concept. As shown in FIG. 8, the elastic vessel 810 may increase or decrease in volume in response to pressure. The capacitance of a capacitor provided through a vessel 810 separating a conductive trace line from a ground plane and filled with a dielectric is dependent on both the volume of dielectric and the separation between the conductive trace line and ground plane. Thus, the elastic vessel 810 may be used, in some embodiments, to further tailor a delay element to provide a desired delay by adjusting the capacitance of a capacitor formed using the elastic vessel 810 through expansion and contraction of the vessel 810.

[00129] The selection of a particular embodiment to implement the delay element 310 of FIG. 3 and/or the delay element 610 of FIG. 6 may be based on a desired relationship between signal amplitude and frequency and a desired beam position, width, and/or sidelobes.

[00130] FIGS. 9 A and 9B are diagrams illustrating the elastic vessel of FIG. 8 used in a RF lens according to some embodiments of the inventive concept. As shown in FIG. 9A, a lens 900 A may include an elastic vessel 910 that is filled with a dielectric 915 that, in some embodiments, comprises a fluid and gas mixture. A fluid and gas supply unit 930 may be configured to fill the elastic vessel 910 with a mixture of fluid and gas through a pressure regulator 935, such as a proportional valve. A pressure relief valve 960, check valve 970, and backpressure module 980 may be connected in series on the opposite port of the vessel 910 from the fluid and gas supply unit 930. In accordance with some embodiments of the inventive concept, the fluid and gas mixture used for the dielectric 915 may comprise a combination of glycerin with a gas including, but not limited to, air and/or an inert gas, such as nitrogen. In some embodiments, the dielectric 915 may include particles or blocks of dielectric material. The dielectric material particles may focus the RF energy that radiates from, and is received by, for example, the radiating elements 515A, 515B, 515C, 515D,

515E, and 515F. The dielectric material particles may be embodied as described in U. S. Patent No. 9,819,094, the disclosure of which is hereby incorporated herein by reference. The dielectric material may be an artificial dielectric of the type described in U.S. Pat. No.

8,518,537 the disclosure of which is hereby incorporated herein by reference. In one example, the dielectric material particles comprise a plurality of randomly distributed particles. The plurality of randomly distributed particles may be made of a lightweight dielectric material. The range of densities of the lightweight dielectric material can be, for example, 0.005 to 0.1 g/cm 3 . At least one needle-like conductive fiber may be embedded within each particle. By varying the number/orientation of conductive fibers inside the particles, the dielectric constant can vary from 1 to 3. Where there are at least two conductive fibers embedded within each particle, the at least two conductive fibers may be in an array like arrangement, i.e., having one or more rows that include the conductive fibers. In some embodiments, the conductive fibers embedded within each particle are not in contact with one another. Further examples of dielectric particles and materials that ma be included within the dielectric are described in U. S. Patent Application No. 15/464,442 entitled "ANTENNAS HAVING LENSES FORMED OF LIGHTWEIGHT DIELECTRIC

MATERIALS AND RELATED DIELECTRIC MATERIALS," the disclosure of which is hereby incorporated herein by reference.

[00131] In other embodiments shown in FIG. 9B, multiple vessels 910A, 910B, and 910C may be connected in series to form a single lens assembly that can be used in an application with multiple radiating elements, such as the antenna system 500 of FIG. 5 including radiating elements 515A, 515B, 515C, 515D, 515E, and 515F. In the example ofFIG. 9B, the lens portion 910A may be oriented in front of radiating elements 515 A and 515B, the lens portion 910B may be oriented in front of radiating elements 515C and 515D, and the lens portion 910C may be oriented in front of radiating elements 515E and 515F. The different shapes of the lens portions 910A, 910B, and 910C may be used to provide multiple beam focus and control.

[00132] In some embodiments of the inventive concept, the elastic vessel 910 may be configured into a variety of geometric shapes and configurations. FIGS. 9C and 9D are plan views of exo-skeletons 990 and 995, respectively, for use in shaping the elastic vessel of FIG. 8 according to some embodiments of the inventive concept. As shown in FIGS. 9C and 9D, the elastic vessel 910 may be received inside the exo-skeletons 990 and 995 and when filled with the dielectric 915 fluid and gas mixture, the elastic vessel 910 may be constrained by the exo-skeleton to form a desired lens shape for focusing RF beam(s) emanating from one or more radiating element, such as the 515A, 515B, 515C, 515D, 515E, and 515F of FIG. 5. [00133] The RF lens embodiments of FIGS. 9 A - 9D may be configured to implement the lens 520 of FIG. 5 by providing geometric shapes and dielectric composition to tailor the radiating pattern of a beam emanating from a radiating element of an antenna system. The lens embodiments of FIGS. 9A - 9D may be configured to provide beam shaping, tilting (e.g., three dimensional tilting) and frequency variation/shifting, i.e., change the operating frequency of a radiating element from one frequency to another.

[00134] FIG. 10 is a multi-layer radiating element 1000 for use in an antenna structure according to some embodiments of the inventive concept. For example, the multi-layer radiating element 1000 may be used to implement any one of the radiating elements 515 A, 515B, 515C, 515D, 515E, and 515F of FIG. 5 and/or be electrically or electromagnetically coupled to any of the radiating elements 515A, 515B, 515C, 515D, 515E, and 515F of FIG. 5 for transmitting a beam having a particular shape or tilt. As shown in FIG. 10, the multi-layer radiating element 1000 may include a plurality of conductive pattern layers 1005 A, 1005B, and 1005C separated by dielectric layers 1010A and 1010B. The patterns formed on the respective conductive pattern layers 1005A, 1005B, and 1005C may be electrically, capacitively, and/or inductively, coupled via intra and inter layer connections. The number of conductive pattern layers and the design of the patterns on each layer may be configured to provide a desired beam shaping and/or tilting effect. In some embodiments, the conductive patterns on adjacent layers may be coupled using a wired connect, such as an RF jumper or other type of wired connection. In other embodiments, a pattern formed on a layer may include a plurality of patterns, such that one or more of the patterns on a layer are coupled to one or more patterns on an adjacent layer while at least one pattern on a layer is

electromagnetically, e.g., capacitively or inductively, coupled to one or more patterns on an adjacent layer without a wired connection therebetween. FIGS. 11 A - 11D illustrate nonlimiting examples of conductive patterns that can be used on conductive pattern layers according to various embodiments of the inventive concept. These various patterns may be selected in combination to form a "book" of layers in the multi-layer radiating element 1000. The various layers comprising the radiating element 1000 may be selected so that one or more of the layers use the same conductive pattern and/or different conductive patterns.

Moreover, the multi-layer radiating element 1000 may be coupled to a single layer radiating element to change the beam shaping and/or tilting of the single layer radiating element.

[00135] Further Definitions and Embodiments:

[00136] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or

"comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Like reference numbers signify like elements throughout the description of the figures.

[00137] It will be understood that, although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element could be termed a second element without departing from the teachings of the inventive concept.

[00138] Terms such as "top," "bottom," "upper," "lower," "above, " "below," and the like are used herein to describe the relative positions of elements or features. For example, when an upper part of a drawing is referred to as a "top" and a lower part of a drawing is referred to as a "bottom" for the sake of convenience, in practice, the "top" may also be called a "bottom" and the "bottom" may also be a "top" without departing from the teachings of the inventive concept.

[00139] Furthermore, throughout this disclosure, directional terms such as "upper,"

"intermediate," "lower," and the like may be used herein to describe the relationship of one element or feature with another, and the inventive concept should not be limited by these terms. Accordingly, these terms such as "upper," "intermediate, " "lower," and the like may be replaced by other terms such as "first," "second," "third," and the like to describe the elements and features.

[00140] It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

[00141] The terminology used herein to describe embodiments of the invention is not intended to limit the scope of the inventive concept.

[00142] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and this specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[00143] The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The aspects of the disclosure herein were chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure with various modifications as are suited to the particular use contemplated.