RELATED APPLICATIONS

[0001] This application claims priority to U.S. provisional Patent Application

61/538,076, "Device for Changing the Waveguide Orientation of an Outdoor Microwave Transmit/Receive Enclosure", filed on September 22, 2011, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present invention relates to the equipment for microwave radio communication, and in particular, to a device for changing the waveguide orientation of an outdoor microwave transmit/receive enclosure and a method of using the device therein.

BACKGROUND

[0003] Because the use of radio frequency (RF) signals having horizontal and vertical polarizations can reduce the RF interference between different microwave transmit/receive enclosures in the same area, many microwave antennas are configured to transmit/receive signals in either horizontal or vertical polarization. To achieve this goal, a microwave transmit/receive enclosure is connected to a microwave antenna by aligning the waveguide port of the transmit/receive enclosure with the waveguide port of the antenna in either horizontal or vertical polarization. For example, an outdoor microwave transmit/receive enclosure can be rotated 90 degrees relative to the antenna to change its output port orientation to match the polarization of the antenna. This approach is not always practical or possible due to the physical size of the enclosure, cabling, and other factors. Another approach is to install the waveguide components between the enclosure's waveguide port and the antenna's waveguide port to align the orientations without rotating the enclosure. An exemplary embodiment of this approached is described below in connection with FIGS. 6 A and 6B. A downside with this scheme is that it introduces additional material and labor cost. Moreover, these waveguide components and associated hardware may be lost in an outdoor environment. SUMMARY

[0004] One objective of the present invention is to provide a device and a method of using the device so that a technician can easily change the orientation of a microwave enclosure's waveguide port using few tools and little time without requiring any additional components.

[0005] According to some embodiments, a microwave transmit/receive enclosure comprises an enclosure housing including an opening and a waveguide rotator that is mounted on the enclosure housing and near the opening. In particular, the waveguide rotator includes a plurality of rectangular openings that are perpendicular to a predefined axis and there is a predefined incremental rotation angle between two immediately adjacent rectangular openings with respect to an axis that is perpendicular to the predefined axis. The waveguide rotator is configured such that a sum of the incremental rotation angles between the plurality of rectangular openings causes a change of orientation to a radio signal that is transmitted through the waveguide rotator.

[0006] According to some embodiments, a waveguide rotator comprises a first waveguide rotator part including a first rectangular opening, wherein the first waveguide rotator part includes a flange and multiple cut-outs evenly distributed along the flange; and a second waveguide rotator part including a second rectangular opening, wherein the second waveguide rotator part is physically linked to the first waveguide rotator part by multiple shoulder screws, each shoulder screw being confined within a respective cut-out at the flange of the first waveguide rotator part, such that a rotation of the second waveguide rotator part may cause a rotation of the first waveguide rotator part through a movement of the multiple shoulder screws within the multiple cut-outs. If there is no rotation angle between the first rectangular opening and the second rectangular opening, there is no change of orientation to a radio signal that travels through the first rectangular opening and the second rectangular opening, respectively. If a sum of rotation angles by the first rectangular opening and the second rectangular opening is approximately 90 degrees, there is a change of orientation to a radio signal that travels through the first rectangular opening and the second rectangular opening, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Different aspects of the present invention as well as features and advantages thereof will be more clearly understood hereinafter as a result of a detailed description of embodiments of the present invention when taken in conjunction with the accompanying drawings, which are not necessarily drawn to scale. Like reference numerals refer to corresponding parts throughout the several views of the drawings.

[0008] FIG. 1 shows an outdoor microwave enclosure rotated 90 degrees with respect to the antenna according to a conventional approach.

[0009] FIG. 2 A shows an outdoor microwave enclosure with the waveguide port oriented for the vertical antenna polarization according to some embodiments of the present invention.

[0010] FIG. 2B shows an outdoor microwave enclosure with the waveguide port oriented for the horizontal antenna polarization according to some embodiments of the present invention.

[0011] FIG. 3 A is a cross-sectional view of an outdoor microwave enclosure with the waveguide port oriented for the vertical antenna polarization as well as an antenna feeder attached to the enclosure according to some embodiments of the present invention.

[0012] FIG. 3B is a cross-sectional view of an outdoor microwave enclosure with the waveguide port oriented for the horizontal antenna polarization as well as an antenna feeder attached to the enclosure according to some embodiments of the present invention.

[0013] FIG. 4A shows the two components of a waveguide rotator including the portion that is inside a microwave transmit/receive enclosure according to some embodiments of the present invention.

[0014] FIG. 4B shows the dimensions of the two components of the waveguide rotator according to some embodiments of the present invention.

[0015] FIGS. 5A to 51 are cross-sectional views of an outdoor microwave enclosure that depict the progressive steps performed by a technician to change the enclosure's waveguide port orientation from the vertical to the horizontal antenna polarization according to some embodiments of the present invention.

[0016] FIG. 6 A shows an alternative device and associated method to change the orientation of the enclosure.

[0017] FIG. 6B shows an enlarged view of the components used in the alternative method shown in FIG. 6A. DESCRIPTION OF EMBODIMENTS

[0018] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous non- limiting specific details are set forth in order to assist in understanding the subject matter presented herein. It will be apparent, however, to one of ordinary skill in the art that various alternatives may be used without departing from the scope of the present invention and the subject matter may be practiced without these specific details. For example, it will be apparent to one of ordinary skill in the art that the subject matter presented herein can be implemented on many types of outdoor radios systems.

[0019] FIG. 1 shows an outdoor microwave enclosure 20 rotated 90 degrees with respect to the antenna 10 according to a conventional approach. As shown in the figure, this approach requires a rotation of the entire enclosure 20 by 90 degrees. Moreover, the rotation of the entire enclosure 20 may interfere with the surrounding cables, mounting brackets, and other fixtures because the relatively large size of the enclosure 20.

[0020] In light of the issues associated with the approach of rotating the entire enclosure 20, the present invention is directed to a new approach that changes the orientation of an enclosure's waveguide port without requiring that the entire enclosure be rotated.

FIGS. 2A and 2B show the side of the enclosure 20 that faces the antenna (not shown). As shown in FIG. 2A, the enclosure 20 has an enclosure housing 25 for housing the duplexer (not shown) therein. It is assumed that the waveguide rotator 30 in FIG. 2A is configured to mate with a vertical antenna polarization 35 and the waveguide rotator 30 in FIG. 2B is configured to mate with a horizontal antenna polarization 40.

[0021] FIGS. 3A and 3B show cross-sectional views of the enclosure 20 and identify the major components that are relevant to some embodiments of the present invention. Like FIGS. 2A and 2B, the waveguide port in FIGS. 3A and 3B is configured to have a vertical antenna polarization (FIG. 3A) and a horizontal antenna polarization (FIG. 3B), respectively.

[0022] As shown in FIG. 3 A, an antenna feeder 45, which is a component of an antenna, is in the vertical orientation and has zero degree of rotation relative to the input/output 60 of a duplexer inside the enclosure housing. The antenna feeder 45 is in physical contact with a waveguide rotator 30. The waveguide rotator 30 includes two components, a first rotator part 55 and a second rotator part 50, each part having a concentric rectangular opening. The antenna feeder 45 is in direct contact with the second rotator part 50 that has zero degree of rotation relative to the duplexer input/output 60. The second rotator part 50 is in direct contact with the first rotator part 50 that also has zero degree of rotation relative to the duplexer input/output 60. Finally, the first rotator part 50 is direct contact with the duplexer input/output 60. In this example, because the antenna feeder 45 and the duplexer input/output 60 are aligned with each other, the waveguide rotator 30 (including the first rotator part 55 and a second rotator part 50 ) does not cause a change of orientation to radio signals that go through the waveguide rotator 30 . In other words, if a signal coming out of the antenna feeder 45 is in the vertical polarization, the signal remains to be in the same orientation when it reaches the duplexer input/output 60. Similarly, a signal coming out of the duplexer input/output 60 remains in the same orientation when it reaches the antenna feeder 45.

[0023] In contrast, FIG. 3B depicts that the antenna feeder 45 is in the horizontal orientation but has 90 degrees of rotation relative to the duplexer input/output 60. The antenna feeder 45 is in direct contact with the second rotator part 50 that has 60 degrees of rotation relative to the duplexer input/output 60. The second rotator part 50 is in direct contact with the first rotator part 50 that has 30 degrees of rotation relative to the duplexer input/output 60. Finally, the first rotator part 50 is direct contact with the duplexer input/output 60. In other words, there is a total of 90 degrees of rotation from the antenna feeder 45 to the duplexer input/output 60 such that the radio signal at the antenna feeder 55 and the radio signal at the duplexer input/output 60 have different orientations. For example, if a signal coming out of the antenna feeder 45 is in the horizontal polarization, the signal will be rotated 90 degrees when it reaches the duplexer input/output 60 with minimal insertion loss and return loss and vice versa.

[0024] FIG. 4 A shows the components of a waveguide rotator 30 including the portion that is inside the enclosure 20 according to some embodiments of the present invention. The second rotator part 50 includes two tabs, each tab having a captive screw 102 for mounting the second rotator part 50 to the outer surface of the enclosure 20. In addition, the second rotator part 50 includes three shoulder screws 104. The first rotator part 55 has a flange 108 with multiple cut-outs 106 evenly distributed along the fiange 108. Each cut-out 106 is configured for hosting one of the three shoulder screws 104. The three cut-outs 106 are designed to confine the movements of the shoulder screws 104 (and therefore the second rotator part 50) relative to the first rotator part 55 within a predefined range. For example, when the second rotator part 50 rotates beyond a predefined range, the shoulder screws 104 will be in direct contact with the flange 108 and cause the first rotator part 55 to rotate in the same direction as the second rotator part 50. Similarly, if the second rotator part 50 is pulled away from the first rotator part 55, the small edges at the cut-outs 106 will engage the shoulder screws 104 such that the first rotator part 55 is also pulled away in the same direction as the second rotator part 50. Finally, the bottom of the first rotator part 55 includes multiple openings 109 to expose the alignment holes 110. As will be described below, these alignment holes 110 are used to align the first rotator part 55 with the duplexer input/output 60. In some embodiments, the components of the waveguide rotator 30 are made of electrically conductive materials such as metal (e.g., aluminum due to its conductivity, cost, and resistance to corrosion) or plastics coated with a layer conductive material.

[0025] FIG. 4B shows the dimensions of the two components of the waveguide rotator according to some embodiments of the present invention. The size of the openings 109 in the waveguide rotator 30 depends at least partially on the frequency of the RF signal going through waveguide rotator 30. For example, the size of the opening at 6 GHz is 34.85mm x 15.8mm. The size of the opening at 42 GHz is 5.68mm x 2.84mm. Although the waveguide rotator 30 includes two components, it is possible to manufacture a waveguide rotator that has only one part or more than two components. Generally, the more components a waveguide rotator includes, the better RF performance it provides. Of course, more components also mean that it is more complicated to manufacture.

[0026] FIGS. 5A to 51 are cross-sectional views of an outdoor microwave enclosure that depict the progressive steps performed by a technician to change the enclosure's waveguide port orientation from the vertical to the horizontal antenna polarization according to some embodiments of the present invention.

[0027] As shown in FIG. 5A and 5B, the technician first loosens the two captive screws 102 securing the second rotator part 50 to the enclosure housing 25.

[0028] As shown in FIG. 5C, the technician then pulls the second rotator part 50 outward by pulling on the two tabs 114 holding the captive screws 102. As a result, the alignment pins 116 in the second rotator part 50 will exit the corresponding holes in the first rotator part 55.

[0029] As shown in FIG. 5D, the technician continues to pull the second rotator part

50 outward. At some point, as described above in connection with FIG. 4A, the shoulder screws (not shown in FIG. 5D) in the back of the second rotator part 50 will engage the flange 108 of the first rotator part 55 and pull the first rotator part 55 outward as well. As a result, the alignment pins 118 in the duplexer input/output 60 will exit the corresponding holes in the first rotator part 55. Note that the flange 108 of the first rotator part 55 will have contacts 112 with the inner surface of the enclosure housing 25, which prevents a potential loss of any of the rotator parts because the first rotator part 55 cannot completely exit the enclosure housing 20.

[0030] As shown in FIG. 5E, the technician then rotates the second rotator part 50 clockwise. As noted above in connection with FIG. 4A, the shoulder screws 104 of the second rotator part 50 will travel in the cut-outs 106 in the fiange 108 of the first rotator part 55. As shown in FIG. 5F, the technician continues rotating the second rotator part 50. At some point, the shoulder screws 104 of the second rotator part 50 will be in direct contact with the flange 108 of the first rotator part 55 and force the first rotator part 55 to rotate clockwise as well. In some embodiments, the openings 109 at the bottom of the first rotator part 55 allows the first rotator part 55 to rotate 30 degrees before the alignment pins 118 of the duplexer input/output 60 are in direct contact with the sides of the openings 109. When this occurs, the alignment pins 118 prevent any further rotation of both the first rotator part 55 and the second rotator part 50. However, the second rotator part 50 has already rotated for 30 degrees when the shoulder screws 104 of the second rotator part 50 travels in the cut-outs 106 in the fiange 108 of the first rotator part 55. Thus, the total rotation angle of the second rotator part 50 is 30 degrees plus 30 degrees, i.e., 60 degrees.

[0031] As shown in FIG. 5G, the technician pushes the second rotator part 50 inward after rotating the second rotator part 50 clockwise as far as 60 degrees. The alignment pins 116 of the second rotator part 50 will insert into the corresponding holes in the first rotator part 55. Note that one skilled in the art would understand that the alignment pins 116 of the second rotator part 50 shown in FIG. 5C cannot be shown in FIG. 5G (which is the same cross-sectional view as FIG. 5C) because of the rotation of the second rotator part 50. As shown in FIG. 5H, the technician continues pushing the second rotator part 50 inward. As a result, the second rotator part 50 pushes the first rotator part 55 inward through the engagement between the shoulder screws 104 of the second rotator part 50 (not shown in FIG. 5H due to the rotation of the second rotator part 50 ) and the fiange 108 of the first rotator part 55. The alignment pins 118 of the duplexer input/output 60 will insert into the corresponding holes in the first rotator part 55. [0032] Finally, as shown in FIG. 51, the technician tightens the two captive screws

102 (only one screw visible in the figure) at the new locations to complete the orientation change.

[0033] As a comparison, FIG. 6A shows an alternative device and associated method to change the orientation of a microwave transmit/receive enclosure. As shown in FIG. 6B, this device includes two separate parts, a straight part 65 and a rotator part 70. The straight part 65 is installed in the enclosure for vertical antenna polarization and the rotator part 70 is installed for horizontal antenna polarization. Because the two parts are not connected with each other, nor are they connected to the enclosure housing, it is very easy to lose one of them or both.

[0034] In contrast, according to some embodiments of the present invention, the two rotator parts are linked to other and they are also connected to the enclosure, it is almost impossible for missing any of the two parts unless the enclosure is substantially destroyed. As such, if a technician wants to change an enclosure from one polarization alignment to the opposite, he just needs to follow the steps above described in connection with FIGS. 5 A to 51, which does not require any sophisticated tools and is also time-efficient.

[0035] The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.