TECHNICAL FIELD

[0001] The present disclosure generally relates to the field of antennas, more specifically, to an antenna structure for wireless systems.

BACKGROUND

[0002] Any background information described herein is intended to introduce the reader to various aspects of art, which may be related to the present embodiments that are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light.

[0003] Wireless communication networks are present in many communication systems today. Many of the communication devices used in the systems include one or more antennas for interfacing to the network. These communication devices often include, but are not limited to, set-top boxes, gateways, cellular or wireless telephones, televisions, home computers, media content players, and the like. Further, many of these communication devices may include multiple interfaces for different types of networks. As a result, one or more antennas may be present on or in a communication device.

[0004] As communication devices continue to get smaller in size, the space allocated in a communication device for communication circuitry, including the antenna(s), may also be reduced. The size or space required for an antenna may vary depending on a number of factors, including the communication network and the choice of antenna type used. One particular operational scenario involves using an Inverted-F Antenna (IFA) in a home wireless network, with a design incorporated onto a printed circuit board located inside a communication device.

[0005] FIG. 1 illustrates a simplified block diagram 100 for an IFA. The elements or sections of FIG. 1 are exemplary and not necessarily in appropriate scale. The IFA includes a conductive element or section 105 of length L. Element 105 operates with similar characteristics to a monopole antenna over a ground plane. One end of element 115 connects to element 105 at a point that is a predetermined distance from one end of element 105. The other end of element 115 connects to element 120. Element 120 is the interface point to an electrical circuit, such as the connection point to a communication circuit. The length L of element 105 may be selected to be approximately one quarter wavelength of the operating frequency of the antenna. The end of element 105 is connected to one end of another conductive element 110. The other end of element 110 is further connected to a conductive copper ground plane 125, which is connected to ground. The ground plane is generally at least as wide as the IFA length (L), and at least one quarter wavelength in height. A smaller height of the ground plane decreases the IFA bandwidth and efficiency. The addition of element 110, also called shorting pin, is important to the structure of an IFA. The distance D between element 115 and element 110 controls the impedance of the IFA. D is chosen such that the radiation resistance is as close as possible to the operating impedance or resistance for the communication circuit connected to element 120. The height H of element 110 may be a small fraction of a wavelength. The radiation properties and impedance are not a strong function of H. Although elements 105, 110 and 115 are described as separate functional elements, they may be implemented as one only conductive element.

[0006] Since the antenna length is usually selected to be less than a full wavelength of the operating frequency for the antenna, the electrical interface for the antenna may electrically operate equivalently to a resistive element. For a general IFA, D is smaller than L-D. The circuit connected to element 120, feed element or feed 120 sees a shorted transmission line a small fraction of a wavelength away from the feed. A shorted transmission line that is a small fraction of a wavelength creates an inductive reactive component. Hence, element 110 electrically operates in a similar manner to adding an inductor in parallel with the remaining equivalent elements in the antenna. Similarly, the open circuit on the IFA creates a capacitance to the right of the feed 120. The feed location is chosen to "balance out" the capacitance (to the right of the feed) and the inductance (to the left of the feed). The inductance and capacitance cancel out, leaving just the radiation resistance. As a result, element 110 reduces the effect of the equivalent series capacitance for the antenna. Although the addition of additional capacitance loading to the right of the feed 120 may be used to reduce the size of the antenna, the position and amount of the additional capacitance may also lead to undesirable effects, including a degradation in antenna impedance or resistance and a degradation in antenna radiation pattern and bandwidth.

[0007] A printed circuit board antenna for an IFA as in FIG. 1 (also called PIFA) additionally relies on characteristics associated with elements and materials around the antenna, in order to determine the relationship between antenna physical parameters and antenna electrical operation parameters. Physical parameters, including the size, thickness, and length of the elements, along with conductivities and dielectric constants for materials used with the antenna, determine the electrical operating frequency for the antenna. The antenna in FIG. 1 relies on the dielectric constant value associated with air (e.g., a dielectric constant value equal to one), or a dielectric material like, e.g., ceramic, or mixture of ceramic and plastic, as one of the physical parameters to determine the electrical parameters and, as a result, determine the physical parameters for, or size of, the constructed antenna. However, an antenna with small physical parameters is desirable given the ever increasing constraints on space in a device, as described earlier. In addition, a large bandwidth of operation is also desirable. Therefore, there is a need to develop antennas, including printed circuit board antennas, that are smaller in physical size than conventional antennas while achieving a large bandwidth of operation and maintaining the same or similar additional electrical operating parameters. The present disclosure is directed towards such a technique.

SUMMARY

[0008] According to an aspect of the present disclosure, an antenna structure is provided including a first conductive element coupled, on a first side, to a communication circuit and to ground and a second conductive element parallel to and connected to the first conductive element over a section of a second side opposite the first side of the first conductive element, the second conductive element having a smaller length than the first conductive element on a direction parallel to the first side of the first conductive element.

[0009] According to an aspect of the present disclosure, a communication apparatus is provided including an antenna structure capable of at least one of radiating a signal and receiving a radiated signal, the antenna structure according to any of the embodiments described in the present disclosure and a communication circuit coupled to the antenna structure and capable of at least one of transmitting a signal to the antenna structure and receiving a signal from the antenna structure.

[0010] According to an aspect of the present disclosure, a method is provided including performing at least one of radiating a signal and receiving a radiated signal using any of the embodiments of the antenna structure according to the present disclosure. [0011] The above presents a simplified summary of the subject matter in order to provide a basic understanding of some aspects of subject matter embodiments. This summary is not an extensive overview of the subject matter. It is not intended to identify key/critical elements of the embodiments or to delineate the scope of the subject matter. Its sole purpose is to present some concepts of the subject matter in a simplified form as a prelude to the more detailed description that is presented later.

[0012] Additional features and advantages of the present disclosure will be made apparent from the following detailed description of illustrative embodiments which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present disclosure may be better understood in accordance with the following exemplary figures briefly described below:

FIG. 1 Illustrates a block diagram of a prior art Inverted-F Antenna;

FIG. 2 illustrates a block diagram of an exemplary communication device in accordance with an aspect of the present disclosure;

FIG. 3 illustrates a block diagram of an exemplary Inverted-F antenna in accordance with an aspect of the present disclosure;

FIG. 4A illustrates a block diagram of a top layer of an exemplary printed circuit board for an exemplary Inverted-F antenna in accordance with an embodiment of the present disclosure;

FIG. 4B illustrates a block diagram of a bottom layer of an exemplary printed circuit board for an exemplary Inverted-F antenna in accordance with an embodiment of the present disclosure;

FIG. 4C illustrates a three-dimensional drawing of exemplary conductive vias connecting the top and bottom layers of the ground plane of a printed circuit board for an exemplary Inverted-F antenna in accordance with an embodiment of the present disclosure;

FIG. 5 is a graph illustrating a characteristic of an exemplary antenna in accordance with an embodiment of the present disclosure;

FIG. 6 illustrates a three-dimensional drawing of an exemplary antenna in accordance with an embodiment of the present disclosure;

FIG. 7 illustrates a three-dimensional drawing of an exemplary communication device in accordance with an embodiment of the present disclosure; and FIG. 8 illustrates a flowchart of an exemplary method of communicating in accordance with an aspect of the present disclosure.

DETAILED DISCUSSION OF THE EMBODIMENTS

[0014] It should be understood that the elements shown in the figures may be implemented in various forms of hardware, software or combinations thereof. Preferably, these elements are implemented in a combination of hardware and software on one or more appropriately programmed general-purpose devices, which may include a processor, memory and input/output interfaces. Herein, the phrase "coupled" is defined to mean directly connected to or indirectly connected with through one or more intermediate components. Such intermediate components may include both hardware and software based components.

[0015] The present description illustrates the principles of the present disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its spirit and scope.

[0016] All examples and conditional language recited herein are intended for educational purposes to aid the reader in understanding the principles of the disclosure and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions.

[0017] Moreover, all statements herein reciting principles, aspects, and embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.

[0018] Thus, for example, it will be appreciated by those skilled in the art that the block diagrams presented herein represent conceptual views of illustrative circuitry embodying the principles of the disclosure. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudocode, and the like represent various processes which may be substantially represented in computer readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown. [0019] The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term "processor" or "controller" should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, read only memory (ROM) for storing software, random access memory (RAM), and nonvolatile storage.

[0020] Other hardware, conventional and/or custom, may also be included. Similarly, any switches shown in the figures are conceptual only. Their function may be carried out through the operation of program logic, through dedicated logic, through the interaction of program control and dedicated logic, or even manually, the particular technique being selectable by the implementer as more specifically understood from the context.

[0021] In the claims hereof, any element expressed as a means for performing a specified function is intended to encompass any way of performing that function including, for example, a) a combination of circuit elements that performs that function or b) software in any form, including, therefore, firmware, microcode or the like, combined with appropriate circuitry for executing that software to perform the function. The disclosure as defined by such claims resides in the fact that the functionalities provided by the various recited means are combined and brought together in the manner which the claims call for. It is thus regarded that any means that can provide those functionalities are equivalent to those shown herein.

[0022] The present disclosure is directed to the problems related to increasing the bandwidth of operation and reducing the size of an antenna used as part of a communication circuit. As devices that use antennas continue to shrink in size, efficient packaging and construction for components, including antennas, becomes more important. Antenna designs may be limited by constraints and inherent tradeoffs between electrical operating parameters and physical characteristics. The present disclosure attempts to address at least some of these issues.

[0023] Some embodiments of the present disclosure are related to an antenna structure, including an antenna that is printed onto or into a printed circuit board. Other embodiments are related to communication devices including the antenna structure. Yet other embodiments are related to methods of communication utilizing the antenna structure. [0024] Turning now to FIG. 2, a block diagram of an exemplary communication device 200 in accordance with an aspect of the present disclosure is shown. Communication device 200 may be used as part of a communication receiver, transmitter, and/or transceiver device including, but not limited to, a handheld radio, a set-top box, a gateway, a modem, a cellular or wireless telephone, a television, a home computer, a tablet, and a media content player. Communication device 200 may include one or more interfaces to wireless networks including, but not limited to Wi-Fi, Institute of Electrical and Electronics Engineers (IEEE) standard 802.11, a Bluetooth network, a Wi-Max network, any number of cellular phone network protocols or other similar wireless communication protocols. Communication device 200 may transmit in a signal format or network different from the received signal format or network. Communication device 200 may receive over-the-air broadcast television (TV) signals, e.g., Advanced Television Systems Committee (ATSC) signals, Digital Video Broadcasting (DVB, e.g., DVB-T2) signals, etc. Further, more than two networks may be used either alternatively or simultaneously together.

[0025] It is important to note that several components and interconnections necessary for complete operation of communication device 200, either as a standalone device, or incorporated as part of another device, are not shown in the interest of conciseness, as the components not shown are well known to those skilled in the art.

[0026] Communication device 200 includes a communication circuit 210 that interfaces with other processing circuits, such as a content source and/or a content playback device, not shown. Communication circuit 210 connects to antenna 220 and includes receiver and/or transmitter circuits well-known in the art. Antenna 220 provides the interface to the airwaves for transmission and reception of signals to and from communication device 200. Antenna 220 may be used for ATSC signals, DVB (e.g., DVB-T2) signals, Wi-Fi signals, Bluetooth signals, Wi- Max signals, etc.

[0027] Communication circuit 210 includes circuitry for improving transmission and/or reception of a signal interfaced through antenna 220 to another device over a wireless network. A received signal from antenna 220 may be amplified by a low noise amplifier and tuned by a set of filters, mixers, and oscillators. The tuned signal may be digitized and further demodulated and decoded (including source and channel decoding). The decoded signal may be provided to other processing circuits 230. The other processing circuits may include, e.g., video processing, audio processing, electronic program guide (EPG) processing, etc. Additionally, communication circuit 210 may generate, convert, and/or format an input signal (e.g., an audio, video, or data signal) from the other processing circuits 230 for transmission through antenna 220. Communication circuit 210 may include a power amplifier for increasing the transmitted signal level of the signal sent from communication device 200 over the wireless network. Adjustment of the amplification applied to a signal received from antenna 220 as well as amplification for a signal transmitted by antenna 220 (e.g., automatic gain control, AGC) may be controlled by a circuit in communication circuit 210 or may be controlled by other processing circuits.

[0028] Communication circuit 210 may also include interfaces to send and receive data (e.g., audio and/or video signals) to other processing circuits 230 (not shown). Communication circuit 200 may further amplify and process the data in order to either provide the data to antenna 220 for transmission or to provide the data to the other processing circuits 230. Communication circuit 210 may receive or send audio, video, and/or data signals, either in an analog or digital signal format. In one embodiment, communication circuit 210 may include an Ethernet interface for communicating data to other processing circuits and an ATSC interface for communicating with antenna 220. Communication circuit 210 may include processing circuits for converting signals between Ethernet format and ATSC format. In one embodiment, communication circuit 210 may include an Ethernet interface for communicating data to other processing circuits and an orthogonal frequency division multiplexing (OFDM) interface for communicating with antenna 220. Communication circuit 210 may include processing circuits for converting signals between Ethernet format and OFDM format.

[0029] Antenna 220 interfaces signals between communication circuit 210 and the wireless network. In one embodiment, antenna 220 may include an IFA. In one embodiment, antenna 220 may be further incorporated into a printed circuit board, such as the printed circuit board used for communication circuit 210. The antenna may include pairs of conductive elements located on more than one layer of the printed circuit board (e.g., two ground planes). The pairs of elements may be connected together using conductive vias in the printed circuit board allowing each pairs of elements to operate as one element. Further details regarding an antenna, such as antenna 220, will be described below.

[0030] It is important to note that more than one antenna 220 may be used in communication device 200. The use of more than one antenna provides additional performance capability and control options. For example, in one embodiment, a first antenna may be oriented in a first orientation or axis with a second antenna oriented in a second orientation or axis. In another embodiment, more than one antenna may be spaced physically at opposite ends of communication device 200 or a larger device that includes communication device 200. In one embodiment, more than one antenna may be used for different communication networks (e.g., ATSC, Wi-Fi, etc.) The use of multiple antennas in embodiments as described herein permit such performance improvements as orientation control, diversity transmission or reception, antenna steering, and multiple input multiple output signal transmission and reception.

[0031] Turning now to FIG. 3, a block diagram of an exemplary Inverted-F antenna 300 in accordance with an aspect of the present disclosure is shown. Antenna 300 may be used as part of a communication device, such as communication device 200 described in FIG. 2. Further, antenna 300 may be included in a larger multifunction device, such as, but not limited to a handheld radio, a set-top box, a gateway, a modem, a cellular or wireless telephone, a television, a home computer, a tablet, and a media content player.

[0032] Antenna 300 includes conductive or radiation elements or sections 305 and 306. Element 305 may couple to element 320 through conductive element 315 at a point nearer to a first end of element 305 and on a first side of element 305. The second end of element 305, the end that is furthest from element 315, may be coupled to a ground plane 325 through conductive element 310. Element 305 may be connected to a first end of conductive elements 310 on a first side/face of element 305. The other (second) end of elements 310 may be connected to the ground plane 325. Ground plane 325 is connected to the circuit's ground.

[0033] Except as described here, the operation of antenna 300, and, in particular, elements 305, 310, 315, 320, and 325, is similar to the operation for similarly numbered elements described for the antenna 100 in FIG. 1. Although elements 305, 310 and 315 are described as separate functional elements, they may be implemented as one only conductive element.

[0034] Element 305 may be rectangular shaped, with a length LI along a first direction (direction of the x axis 301, or x direction) and a width Wl along a second direction (direction of the y axis 302, or y direction) perpendicular to the first direction. In one embodiment, length LI may be greater than width Wl . Element 306 may also be rectangular in shape, with a length L2 along the first direction and a width W2 along the second direction. In one embodiment, length L2 may be smaller than length LI. In one embodiment, length L2 may be greater than width W2. In one embodiment, width W2 may be approximately, substantially the same as or substantially equal to width Wl. In one embodiment of the present disclosure, being approximately, substantially the same as, or substantially equal to means having size differences within a +5- 10% deviation or margin.

[0035] Element 310 may also be rectangular shaped, with a length L3 along the first direction 301 and a width W3 along the second direction 302. Width W3 is equivalent to height H in FIG. 1. In one embodiment, the length L3 may be smaller than LI, L2, Wl and W2. In one embodiment, the width W3 may be smaller than LI, L2, Wl and W2. Element 315 may be triangular shaped, with a length L4 along the first direction 301 and a width W4 along the second direction 302. In one embodiment, width W4 may be approximately or substantially equal to W3. In one embodiment, the length L4 may be smaller than LI and L2. The ground plane 325 may also be rectangular in shape, with a length L5 in the first direction 301 and a width W5 in the second direction 302. In one embodiment, the length L5 may be approximately or substantially equal to L4.

[0036] Antenna or IFA 300 may differ from antenna or IFA 100 in several ways. A first difference is that element 315 may be further away from element 310 than from the first end of element 305. The first difference means that Dl in FIG. 3 may be larger than D in FIG. 1 for a similar antenna dimension (L approximately equal to LI). An increased distance Dl between the feed point 320 and the shorting pin 310 increases the inductive loop length between the feed 320 and ground plane 325, through element 315. As a result, IFA 300 may be seen as a variant IFA combined with a loop antenna.

[0037] The larger distance Dl also increases the bandwidth of antenna 300. In general, IFAs have a bandwidth around 10% of the resonant frequency, which is the center frequency of operation. For example, an IFA with a resonant frequency around 2.5GHz may generally have a bandwidth of operation around 250MHz. However, for operation in the US Digital Television (DTV) high band including Ultra High Frequency (UHF) broadcast channels 14 to 51, and a frequency range from 470 MHz to 700 MHz, the antenna needs a 230MHz bandwidth for a center frequency of around 585MHz. This bandwidth is equivalent to almost 40% of the center frequency. The larger distance Dl increases the bandwidth of antenna 300 to the percentage required for the US DTV High Band.

[0038] A second difference between antenna 300 and antenna 100 is that antenna 300 may include a second radiating element 306 in addition to a first radiating element 305, with element 306 being smaller in length than element 305. Element 306 may be parallel, adjacent and in contact with element 305 over a section of a second side/face of element 305 opposite the first side of element 305, and starting from or closest to the first end of element 305. The section of the second side on which there is contact between the first element 305 and the second element 306 may be substantially equal to a length L2 of the second conductive element 306. A short current path is generated in the first element 305, which is operable to radiate or receive radiated signals in a first frequency range. A longer current path is generated in the second element 306 such that the antenna operates or is operable to radiate or receive radiated signals in a second frequency range different from the first frequency range, including lower frequencies. The first element 305 and second element 306 combine to form a stepped element with the same effect described above, wherein stepped element means that the first element 305 and the second element 306 have different lengths LI and L2, respectively, e.g., as depicted in FIG. 3. For the exemplary US DTV antenna, the introduction of the second radiating element 306 permits the lower frequency range to extend from approximately 550 MHz down to 470MHz. As a result, antenna 300 may be utilized for a US DTV High Band. In one embodiment, the length L2 may be greater than approximately LI - Dl - L3, so that the higher frequencies in the second frequency range are not affected. In other words, the second element 306 should extend from or close to the first end of the first element 305 to a point beyond the feed element 320 along the x direction 301.

[0039] In accordance with the present disclosure, an antenna or element operating in a frequency range, or being operable to radiate or receive radiated signals in a frequency range, corresponds to providing or receiving radiation is the frequency range according to an efficiency metric. The efficiency metric may be based, e.g., on the return loss of the antenna or element. In one embodiment, the operable frequency range of an antenna or element may include frequencies for which the return loss is below a threshold return loss. In one embodiment, the threshold return loss may be -5dB. In one embodiment, the threshold return loss may be -lOdB. Other threshold return loss values may be utilized without departing from the scope of the present disclosure.

[0040] A third difference between antennas 300 and 100 is that, unlike element 115, element 315 may be a tapered strip line, having an inverted triangular shape with a first side of the triangle being parallel, adjacent and fully in contact with element 305 on the first side/face of element 305, and starting from or closer to the first end of element 305 (and farther from the second end of element 305). The triangle vertex opposite the first side of the triangle connects to element 320. The tapered line 315 improves impedance matching with the electrical circuit compared to element 115 of IFA 100, by creating additional current paths between the feed 320 and ground 325. Hence, the tapered line 315 helps to overcome the mismatch resulting from a smaller capacitance due to the increase of the distance Dl between the feed point 320 and the shorting pin 310.

[0041] FIGs 4A, 4B and 4C illustrate an exemplary Inverted-F antenna similar to antenna 300 and formed on a printed circuit board (PCB) to be used in a communication device similar to device 200, in accordance with an embodiment of the present disclosure. FIG. 4A illustrates a block diagram of the top layer 400A of the PCB for the exemplary Printed Inverted-F antenna (PIFA) 400. Except as described here, the operation of antenna 400, and in particular, elements 405, 406, 410, 415, 420, and 425, is similar to the operation for similarly numbered elements described for the antenna 300 in FIG. 3. Sections 435, 440, 445, 450 and 455 are not conductive. Element 480 is an optional hole in PCB 400 for possible signal coax cable crossing to the bottom of the PCB, if necessary. Additional matching components (e.g., capacitors, resistors, etc., not shown) may be optionally connected to the feed 420 in the particular implementation. Conductive vias (or metal pins) may cover the perimeter of ground plane 425 for connection to the ground plane on the bottom layer 400B of PCB 400, illustrated in FIG. 4B.

[0042] FIG. 4B illustrates a block diagram of the bottom layer 400B of PCB 400 for the exemplary PIFA. In the bottom layer, a bottom version of the ground plane 426 has the same shape as the top layer of the ground plane 425. In addition, conductive vias may cover the perimeter of the ground planes connecting the top layer 425 to the bottom layer 426 (e.g, vias 427 to 431) and perpendicular to both layers 425 and 426 (alongside the z direction 403). The z direction or axis 403 is perpendicular to the plane formed by the x axis 401 and the y axis 402. Sections 451, 456 and 460 are not conductive.

[0043] FIG. 4C illustrates a drawing 400C of the longitudinal view of some conductive vias (or metal pins) connecting the top layer 425 and bottom layer 426 of the ground plane of the exemplary PIFA 400, including conductive vias 427 to 431.

[0044] In one embodiment, for use in the US DTV High Band UHF frequency range covering the whole band between 470MHz and 700MHz, the PCB size may have dimensions of 200mm in length by 210mm in width. [0045] FIG. 5 illustrates a graph 500 of an electrical characteristic of an antenna similar to IFA 300 and PIFA 400 in accordance with aspects of the present disclosure. Graph 500 represents the scalar value for return loss of the antenna (e.g., 300, 400) versus frequency as measured at the antenna electrical terminal (e.g., element 420). Graph 500 includes an x axis 510 displaying frequency in Megahertz (MHz). Graph 500 also includes a y axis 520 displaying return loss, displayed as (S 1,1), in decibels (dB). Line 530 displays the value of return loss versus frequency for antenna. Points 550, 560 and 570 correspond to approximately 470 MHz, 570MHz and 700 MHz, respectively. Therefore, graph 500 depicts the return loss of an antenna for use in the US DTV High Band UHF frequency range covering the whole band between 470MHz and 700MHz.

[0046] FIG. 6 illustrates a three-dimensional drawing of an exemplary antenna 600 in accordance with an embodiment of the present disclosure. Antenna 600 may include a PIFA 610 combined with a loop antenna 620 within the inner walls of a plastic or metal case 630. The plastic or metal case 630 may be optional and similar to cases used for electronic devices, e.g., gateways, set-tops, etc. In one embodiment, the PIFA 610 may be placed 10 mm apart from the case 630 in the direction of the z axis, i.e., the z direction 603. The PIFA 610 is similar to PIFA 400 and may cover the US DTV High Band UHF range of 470-700MHz. The loop antenna 620 may surround the PIFA 610 alongside the inner perimeter of the case according to the x direction 601 and y direction 602 in FIG. 6. The loop antenna 620 may be placed on a plane near the side of the case opposite PIFA 510 according to the z direction 603 in FIG. 6. The loop antenna 620 may be coupled to a feed point on one end 622 and to ground on a second end 624. The feed point of loop antenna 620 connects or couples loop antenna 620 to a communication circuit (not shown), similarly to feed or element 420, 320 and 120. The ground of loop antenna 620 is similar to ground plane 125, 325, 425-426. In one embodiment, the z direction 603 and x direction 601 may form a horizontal plane and the y direction 602 may be a vertical direction. In one embodiment, the x direction 601 and y direction 602 may form a horizontal plane and the z direction 603 may be a vertical direction.

[0047] The loop antenna 620 may operate in the US DTV Mid Band, including Very High Frequency (VHF) broadcast channels 7 to 13, with a frequency range from 174MHz to 217MHz. Due to the limitation on the size of the case 630, loop antenna 620 may include a meander section 625, in order to increase the length of the loop. [0048] The distance between the PIFA 610 and loop antenna 620 may seek to minimize the interference between the antennas, particularly the effect of the loop antenna 620 on the PIFA 610, potentially affecting the bandwidth of the PIFA 610. The meander section 625 may be placed on the x and z plane, on the side of the case farthest away from PIFA 610, according to the y direction 602, in order to maximize the distance between the antennas 610 and 620. On each side of the PIFA 610 in the x direction 601, a wire of a small diameter may be applied to the loop antenna 620 in order to decrease the effect on the PIFA 610. In one embodiment, the wire may have a 2mm diameter. In one embodiment, the meander 625 may itself be formed on a small PCB and connected to the wire of the loop antenna 620 on each side of the small PCB.

[0049] According to an aspect of the present disclosure, an antenna structure 300, 400, 600 is described including a first conductive element 305, 405 coupled, on a first side, to a communication circuit and to ground 325, 425, and a second conductive element 306, 406 parallel to and connected to the first conductive element 305, 405 over a section of a second side opposite the first side of the first conductive element 305, 405, the second conductive element 306, 406 having a smaller length than the first conductive element 305, 405 on a direction parallel to the first side of the first conductive element 305, 405 (the x direction 301, 401).

[0050] According to an embodiment of the antenna structure 300, 400, 600, a length of the section of the second side may be substantially equal to a length of the second conductive element 306, 406.

[0051] According to an embodiment of the antenna structure 300, 400, 600, the second conductive element 306, 406 may have substantially the same width as the first conductive element 305, 405. In other words, a width of the second conductive element 306, 406 may be substantially equal to a width of the first conductive element 305, 405.

[0052] According to an embodiment of the antenna structure 300, 400, 600, the second conductive element 306, 406 may connect to the first conductive element 305, 405 near or on a first end of the first conductive element 305, 405 perpendicular to the first side of the first conductive element 305, 405.

[0053] According to an embodiment of the antenna structure 300, 400, 600, the first conductive element 305, 405 may generate a short current path to ground 325, 425 and the second conductive element may generate a long current path to ground 325, 425. [0054] According to an embodiment, the antenna structure 300, 400, 600 may further include a third conductive element 310, 410 perpendicular to and connected to the first conductive element 305, 405 on a first end of the third conductive element 310, 410 and near the first end of the first conductive element 305, 405 and on the first side of the first conductive element 305, 405, the third conductive element 310, 410 being connected to ground 325, 425 on a second end of the third conductive element 310, 410 opposite the first end of the third conductive element 310, 410.

[0055] According to an embodiment, the antenna structure 300, 400, 600 may further include a fourth conductive element 315, 415 being triangular shaped, a first side being parallel to and fully connected to the first side of the first conductive element 305, 405 near a first end of the first conductive element 305, 405 and a vertex opposite the first side connecting to a signal feed 320, 420 coupled to the communication circuit.

[0056] According to an embodiment, the antenna structure 300, 400, 600 may further include a fifth conductive element including at least one ground plane 325, 425, 426 connected to the second end of the third conductive element 310, 410.

[0057] According to an embodiment of the antenna structure 300, 400, 600, two ground planes 425, 426 may be connected using conductive vias ,e.g., vias 427 to 431 along the perimeter of the two ground planes 425, 426.

[0058] According to an embodiment of the antenna structure 300, 400, 600, the antenna structure may be an Inverted-F antenna 300, 400, 610.

[0059] According to an embodiment of the antenna structure 300, 400, 600, the antenna structure may be formed on a printed circuit board 400, 600.

[0060] According to an embodiment of the antenna structure 300, 400, 600, the antenna structure may operate in a second frequency range including lower frequencies than a first frequency range of radiation of the first conductive element 305,405.

[0061] According to an embodiment of the antenna structure 300, 400, 600, the second frequency range may include frequencies in the Ultra High Frequency range of digital television systems. For example, the second frequency range may include frequencies in the US DTV high band including UHF broadcast channels 14 to 51, and a frequency range from 470 MHz to 700 MHz. [0062] According to an embodiment of the antenna structure 300, 400, 600, the first frequency range may include frequencies in the Ultra High Frequency range of digital television systems. For example, the first frequency range may include frequencies in the US DTV high band including a frequency range from approximately 570 MHz to 700 MHz.

[0063] According to an embodiment, the antenna structure 300, 400, 600 may further include a sixth conductive element 620 coupled to the communication circuit and to ground 325, 425, 426 and operating in a third frequency range, the sixth conductive element 620 being a loop antenna element surrounding the perimeter of the inverted-F antenna 610 on a separate plane than a plane of the inverted-F antenna 610.

[0064] According to an embodiment of the antenna structure 300, 400, 600, the loop antenna element 620 may include a meander 625 section on a plane perpendicular to the plane of the inverted-F antenna 610 and parallel to the first side of the first conductive element 305. The meander 625 may itself be formed on a small PCB and connected to the wire of the loop antenna element 620 on each side of the small PCB.

[0065] According to an embodiment of the antenna structure 300, 400, 600, the third frequency range may include frequencies in a high frequency section of the Very High Frequency range of digital television systems. For example, the third frequency range may include frequencies in the US DTV Mid Band, including VHF broadcast channels 7 to 13, with a frequency range from 174MHz to 217MHz.

[0066] FIG. 7 illustrates a three-dimensional drawing 700 A of an exemplary communication device 700 in accordance with an embodiment of the present disclosure. Communication device 700 is similar to communication device 200, including similar functionalities. Communication device 700 includes a combined PIFA-loop antenna 710, 720 similar to antenna 610, 620, and also to antenna 220. Elements 722, 724 and 725 of loop antenna 720 are also similar to elements 622, 624 and 625 of loop antenna 620, respectively. Communication device 700 may also include a plastic or metal case 730 similar to plastic or metal case 630. In addition, communication device 700 may include a PCB 740 including a communication circuit and/or other processing circuits similar to 210 and 230, respectively. PCB 740 in FIG. 7 does not show any of the circuit components, e.g., tuner(s), integrated circuit(s), capacitor(s), resistor(s). connector(s), etc. for simplicity of design. In one embodiment, the PIFA 710 may be placed on a plane 10 mm apart from the case 730 in the z direction 703. In one embodiment PCB 740 may be placed on a plane 4 mm apart from the PIFA 710 in the z direction 703, i.e., on the side opposite the case 730.

[0067] Moreover, communication device 700 may optionally include elements not shown in FIG. 7, including a Hard Disk Drive (HDD) mounted to the internal structure of the case or chassis, Light Emitting Diodes (LED's) to display various statuses, reset button, power connector, heat spreader, Ethernet connector, Wi-Fi protection setup (WPS) buttons to allow devices to join Wi-Fi protected network without giving network name and password, etc. In one embodiment, the heat spreader may be placed on a plane 10 mm apart from the PCB 740 in the z direction 703. In one embodiment, the HDD may be placed on a plane 5 mm apart from the heat spreader in the z direction 703.

[0068] Furthermore, in one embodiment, communication device 700 may optionally include an antenna socket (not shown in FIG. 7) for an external antenna, e.g., rabbit ears antenna, operating in the US DTV Low Band, including VHF broadcast channels 2 to 6, with a frequency range from 54MHz to 88MHz. As a result, communication device 700 may operate in the entire US DTV frequency spectrum with its combined three in one antenna (PIFA 710, loop 720 and rabbit ears (not shown)). By including some of the antenna elements in the device, the user does not need to buy expensive antennas for DTV reception. A rabbit ears antenna is quite inexpensive.

[0069] Communication device 700 may operate as a US DTV gateway which receives ATSC video/audio/data content and streams the content via Ethernet and/or by wireless means (e.g., dual-band 802.1 lac 2x2 Wi-Fi in 2.4GHz and 5GHz). The US DTV gateway may be useful as a complement to Over-the-top (OTT) devices, including set-top boxes, PC, TV, etc. Communication device 700 may also be included in the OTT device itself, potentially eliminating the need for a wireless transmitter. Communication device 700 may also be coupled to the OTT device through a cable based network similar to the US DTV cable distribution. The cable distribution may be inside the user's premises.

[0070] It is to be understood that communication device 700 may be useful to other digital television standards (e.g., DVB-T2) with a similar or approximate frequency range of operation.

[0071] According to an aspect of the present disclosure, a communication apparatus 200, 700 is described for performing communication, the apparatus including an antenna structure (220, 710, 720) capable of at least one of radiating a signal and receiving a radiated signal, the antenna structure (220, 710, 720) according to any of the embodiments of the present disclosure, and a communication circuit (210, 740) coupled to the antenna structure (220, 710, 720) and capable of at least one of transmitting a signal (220, 710, 720) to the antenna structure and receiving a signal from the antenna structure (220, 710, 720). The antenna structure may include a first conductive element 305, 405 coupled, on a first side, to a communication circuit and to ground 325, 425 and a second conductive element 306, 406 parallel to and connected to the first conductive element 305, 405 over a section of the second side opposite the first side of the first conductive element 305, 405, the second conductive element 306, 406 having a smaller length than the first conductive element 305, 405 on a direction parallel to the first side of the first conductive element 305, 405. The antenna structure may further include any of the additional embodiments previously described and/or illustrated, including 300, 400 and 600.

[0072] According to an embodiment, the communication apparatus 200, 700 may further include an external antenna element coupled to the circuit 210, the external antenna element operating in a fourth frequency range different from the first frequency range, the second frequency and the third frequency range. The external antenna element may be, e.g., a rabbit ears antenna.

[0073] According to an embodiment of the communication apparatus 200, 700, the fourth frequency range includes lower frequencies than the third frequency range. For example, the fourth frequency range may include the US DTV Low Band, including VHF broadcast channels 2 to 6, with a frequency range from 54MHz to 88MHz. And the third frequency range may include frequencies in the US DTV Mid Band, including VHF broadcast channels 7 to 13, with a frequency range from 174MHz to 217MHz.

[0074] According to an embodiment of the communication apparatus 200, 700, the fourth frequency range includes frequencies in a low section of the Very High Frequency range of digital television systems. For example, the fourth frequency range may include the US DTV Low Band, including VHF broadcast channels 2 to 6, with a frequency range from 54MHz to 88MHz.

[0075] FIG. 8 illustrates a flowchart 800 of an exemplary method of communicating according to an aspect of the present disclosure. The method includes, at step 810, performing at least one of radiating a signal and receiving a radiated signal using an antenna structure according to any of the embodiments of the present disclosure. The antenna structure may include a first conductive element (e.g., 305, 405) coupled, on a first side, to a communication circuit and to ground (e.g., 325, 425) and operating in a first frequency range, and a second conductive element (e.g., 306, 406) parallel to and connected to the first conductive element (e.g., 305, 405) on a second side opposite the first side of the first conductive element (e.g., 305, 405), the second conductive element (e.g., 306, 406) operating in a second frequency range different from the first frequency range. The antenna structure may further include any of the additional embodiments previously described and/or illustrated, including 300, 400 and 600.

[0076] Finally, at step 820, the method may further include performing at least one of transmitting a signal to the antenna structure and receiving a signal from the antenna structure using a communication circuit. The communication circuit may be any of the embodiments of a communication circuit previously described, including 200 and 700. The communication circuit 200, 700 may demodulate and process the received signal. The communication circuit 200. 700 may process and modulate the signal to be transmitted. The step 820 is optional and may be removed or bypassed.

[0077] Any of the steps of the method 800, may be implemented as a computer program product comprising computer executable instructions which may be executed by a processor. The computer program product having the computer-executable instructions may be stored in the respective non-transitory computer-readable storage media of the respective above mentioned devices. A computer-readable storage medium as used herein is considered a non-transitory storage medium given the inherent capability to store the information therein as well as the inherent capability to provide retrieval of the information therefrom. A computer-readable storage medium may be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0078] It is to be appreciated that the various features shown and described for the antenna structure, communication apparatus or method are interchangeable. Unless otherwise indicated, a feature shown in one embodiment may be incorporated into another embodiment. Further, the features described in the various embodiments may be combined or separated unless otherwise indicated as inseparable or not combinable.

[0079] As noted before, the functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. Also, when provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared.

[0080] It is to be further understood that, because some of the constituent system components and methods depicted in the accompanying drawings are preferably implemented in software, the actual connections between the system components or the process function blocks may differ depending upon the manner in which the present disclosure is programmed. Given the teachings herein, one of ordinary skill in the pertinent art will be able to contemplate these and similar implementations or configurations of the present disclosure.

[0081] Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present disclosure is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope of the present disclosure. In addition, individual embodiments can be combined, without departing from the scope of the present disclosure. All such changes and modifications are intended to be included within the scope of the present disclosure as set forth in the appended claims.