Patent Publication Number: US-2023155299-A1

Title: Antenna array grouping

Description:
TECHNICAL FIELD 
     This disclosure relates to wireless communications and in particular to a method and system for antenna array grouping. 
     BACKGROUND 
     In wireless communication systems today, groups of antennas are used to increase the effective antenna aperture of a radio used in wireless communications. Such communication systems include New Radio (NR) (also known as 5G) and Long Term Evolution (LTE) (also known as 4G). Increasing the effective aperture increases the antenna directivity. Increasing antenna directivity helps to overcome isotropic free space path loss. The receive (RX) and transmit (TX) functionality is usually orthogonalized using either the time domain (time division duplex, TDD), or the frequency domain (frequency division duplex, FDD). In both cases, the momentary spectrum efficiency is halved compared to using shared time and frequency resources for both reception and transmission. Such a system is usually referred to as an on-frequency, full-duplex system. Such systems present self-interference. This is the case because a transmitter will leak unwanted signal power into a nearby receiver. This leakage can be significantly stronger than the wanted receive signal power level, and thus, the leakage degrades the receiver sensitivity by several orders of magnitude. 
     On-frequency, full-duplex systems make use of several techniques that when combined, achieve substantial suppression of the unwanted, self-induced, transmit interferer in the receiver. In practice, three approaches may be exercised in parallel. These include: 1) antenna port isolation in terms of physically separating antennas and/or using separate polarizations, and/or using isolator/circulator functionality for cases where the antenna is shared for transmission and reception; 2) analog cancelation loops from the transmitter to the receiver in order to suppress the unwanted interferer to a level where receiver nonlinearity does not degrade performance beyond what is acceptable; and 3) cancellation in the digital baseband where remaining transmit leakage can be cancelled, and where modeled transmit nonlinearities can be taken into account. Depending on system requirements, one or possibly two of the aforementioned techniques may be omitted, but for high performing cellular systems, usually demanding upwards of 100 dB of total transmit interferer suppression, all three approaches are typically fully exploited. 
     An antenna array includes multiple antenna elements, each with its own feed. By adjusting the phase between elements (or sub-arrays), an antenna array can be steered electronically, without having to physically move the antenna system. For multiple input multiple output (MIMO) systems using group antennas, one inherent problem is that multiple transmitters will simultaneously induce self-interference in each receiver. Thus, the complexity of self-cancellation grows. For large antenna arrays having multiple transceiver (receiver and transmitter) integrated circuits (ICs), (also referred to as “tiles”) to drive the antenna ports, additional problems occur as analog cancellation paths between transmitters and receivers might call for analog inter-chip signaling, including radio frequency (RF) signaling. This, in turn, may complicate manufacture of the array beyond what is feasible. Such systems might need to rely only on antenna isolation techniques and digital cancellation. As a result, completely separated antenna panels (RX and TX) may be used. This has three potentially negative side effects when driven by individual radio ICs: 1) a large distance between antenna panels makes the total footprint large; 2) using a common transceiver IC for cost reasons means that either TX or RX will not be used so that unused chip area is expected; and 3) using separate transceiver ICs drives research and development, validation, and production cost as two ICs must be developed, and their respective volume is half the total volume. Circulators can only remove leakage from a transmitter to a receiver connected to the same circulator. Leakage from a nearby antenna cannot be distinguished from the wanted signal to be received by the antenna. 
     SUMMARY 
     Some embodiments advantageously provide a method and system for antenna array grouping to address the problems described above. In some embodiments, antenna elements in a group of antenna elements are arranged to reduce self-interference leakage. In some embodiments, TX and RX circuits are interleaved in the group antenna to avoid the above-described interference, while preserving good isolation between TX and RX antenna elements when operated in on-frequency full-duplex mode. In some embodiments, the antenna elements are arranged such that the nearest interfering TX antenna elements are connected to the same radio IC as the victim RX antenna elements in order to enable on-chip analog cancelation techniques. This is accomplished while using the same radio IC, i.e., tile, for all sub-arrays across the panel, but the geometry is alternated in order to effectively create more TX to RX isolation when antenna elements are connected to different radio ICs. 
     In some embodiments, a transmit and receive antenna array panel are interleaved into a joint antenna array structure where the physical interleaving is shaped to enable on-chip analog self-interference cancellation methods for the most significant TX aggressors. In an on-frequency full-duplex use case, this enables additional suppression without sacrificing total antenna area or antenna directivity. The same radio ICs can be used across the interleaved TX/RX antenna panel, thereby achieving a significant cost advantage in terms of research and development, validation, and chip manufacturing volume. 
     Advantages of configurations disclosed herein include greater receiver sensitivity, lower interference at receivers caused by transmissions from nearby transmitters (which are now further away), ease of design and manufacture, as well as scalability. 
     According to one aspect, a communication apparatus to mitigate transmit to receive leakage in on-frequency full-duplex systems having a plurality of antenna elements is provided. The communication apparatus includes a panel having transceiver integrated circuits, ICs, the panel including a plurality of transceiver integrated circuits, ICs, each transceiver IC having a row of transmit circuits and a row of receive circuits, the transceiver ICs being arranged so that a row of receive circuits on one transceiver IC is adjacent to a row of receive circuits on an adjacent transceiver IC. 
     According to this aspect, in some embodiments, the communication apparatus further comprises a plurality of panels, the plurality of panels being arranged side by side so that a row of receive circuits on a transceiver IC on a first panel is aligned with a row of receive circuits on a transceiver IC on a second panel. In some embodiments, a plurality of transceiver ICs on the panel are arranged by rotating every other transceiver IC so that rows of receive circuits on one panel are in a same row as a row of receive circuits on an adjacent panel. In some embodiments, the rotation is approximately 180 degrees. In some embodiments, the plurality of panels are arranged side by side so that a row of receive circuits on a transceiver IC on a first panel is aligned with a row of receive circuits of a transceiver IC on a second panel. In some embodiments, a distance between adjacent panels is less than a wavelength at a frequency of operation of the plurality of antenna elements. 
     According to yet another aspect, a method for arranging transceiver integrated circuits, ICs, to mitigate transmit to receive leakage in on-frequency full-duplex systems having a plurality of antenna elements is provided. The method includes arranging a row of transmit circuits and a row of receive circuits on a transceiver IC; and arranging a plurality of transceiver ICs on a first panel so that a row of receive circuits on one transceiver IC is adjacent to a row of receive circuits on an adjacent transceiver IC. 
     According to this aspect, in some embodiments, the method further includes arranging a plurality of panels side by side so that a row of receive circuits on a transceiver IC on the first panel is aligned with a row of receive circuits on a transceiver IC on a second panel. In some embodiments, the method further includes arranging a plurality of panels and arranging the plurality of transceiver ICs on the first panel by rotating every other transceiver IC so that rows of receive circuits on the first panel are in a same row as a row of receive circuits on an adjacent panel of the plurality of panels. In some embodiments, the rotation is approximately 180 degrees. In some embodiments, the method further includes arranging the plurality of panels side by side so that a row of receive circuits on a transceiver IC on a first panel is aligned with a row of receive circuits of a transceiver IC on a second panel. In some embodiments, a distance between adjacent panels is less than a wavelength at a frequency of operation of the plurality of antenna elements. 
     According to another aspect, an array of transceiver integrated circuits, ICs, is configured to be in communication with an array of antenna elements, each transceiver IC having a row of receive circuits and a row of transmit circuits, transceiver ICs in the array of transceiver ICs being arranged so that a row of receive circuits on one transceiver IC is adjacent to a row of receive circuits on an adjacent transceiver IC. 
     According to this aspect, in some embodiments, two adjacent transceiver ICs are arranged so that a row of receive circuits on one transceiver IC are more distant to a row of transmit circuits on the other adjacent transceiver IC than to a row of receive circuits on the other adjacent transceiver IC. In some embodiments, transceiver ICs are arranged in panels so that a row of receive circuits on one panel is in a same row as a row of receive circuits on an adjacent panel. In some embodiments, a distance between adjacent transceiver ICs is less than a wavelength at a frequency of operation of at least one antenna in communication with one of the adjacent transceiver ICs. In some embodiments, a first transceiver IC is rotated 180 degrees with respect to an orientation of a second transceiver IC adjacent to the first transceiver IC. 
     According to yet another aspect, a panel of transceiver integrated circuits, ICs is configured such that each transceiver IC has a row of transmit circuits and a row of receive circuits, every other transceiver IC in a plurality of rows of transceiver IC on the panel being rotated with respect to an adjacent transceiver IC on the panel. 
     According to this aspect, in some embodiments, any two adjacent transceiver ICs on the panel are arranged so that a row of receive circuits on one IC are more distant to a row of transmit circuits on the other adjacent transceiver IC than to a row of receive circuits on the other adjacent transceiver IC. 
     According to another aspect, a method of manufacturing a panel of transceiver integrated circuits, ICs, for electrical communication with a plurality of antenna elements is provided. The method includes placing a first transceiver IC on a printed circuit board; and placing a second transceiver IC on the printed circuit board so that a first row of receive circuits on the first transceiver IC is adjacent to a second row of receive circuits on the second transceiver IC. 
     According to this aspect, in some embodiments, the second transceiver IC is placed such that the second transceiver IC is rotated with respect to an orientation of the first transceiver IC. In some embodiments, the second transceiver IC is rotated by an angle in the range of 178 to 182 degrees. In some embodiments, the second transceiver IC is rotated by an angle in the range of 170 to 190 degrees. In some embodiments, the second transceiver IC is rotated by 180 degrees. In some embodiments, a distance between the first and second transceiver ICs are positioned to be less than a wavelength apart at a frequency of operation of the plurality of antenna elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of embodiments described herein, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: 
         FIG.  1    is a block diagram of a transmit panel and a receive panel; 
         FIGS.  2 A and  2 B  are block diagrams comparing two different TX/RX arrangements; 
         FIGS.  3 A and  3 B  are block diagrams comparing two different TX/RX arrangements; 
         FIG.  4    is a flowchart of an example process for grouping antenna elements to mitigate transmit to receive leakage in on-frequency full-duplex systems; and 
         FIG.  5    is a flowchart of an example process placing transceiver (TRX) integrated circuits (ICs) on a printed circuit board. 
     
    
    
     DETAILED DESCRIPTION 
     Before describing in detail example embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to antenna array grouping. Accordingly, the system and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. 
     As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. 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,” “comprising,” “includes” and/or “including” when used herein, 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. 
     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 disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication. 
     It is also noted that the terms “IC” and “IC chip” are used interchangeably herein. 
     Referring to the drawing figures, where like reference designators refer to like elements,  FIG.  1    shows two 2×4 antenna panels, one panel being a transmit antenna panel  10  and the other panel being a receive antenna panel  12 . Each panel has two dedicated radio ICs: the TX IC 1   14 - 1  and TX IC 2   14 - 2  on panel  10 ; and the RX IC  1   16 - 1  and RX IC 2   16 - 2  on panel  12 . The TRX ICs serve 4 antenna elements each. In a traditional system, the distances between the panels  10  and  12  can be large, and thus offer superior antenna isolation between transmission and reception when operated in on-frequency full-duplex mode. Some fundamental drawbacks of this configuration are discussed above. Note that each transmitter fed by TXIC 1  can be connected to a sub-array. Combiners or splitters are typically used on the antenna substrate to divide the signal and maintain impedance matching. 
     In order to make use of a single transceiver IC, (also referred to as a tile), in accordance with the disclosure herein, the two antenna panels can be merged into one structure as shown in  FIG.  2 A .  FIG.  2 A  shows a panel  18  that has mounted thereon a transceiver IC  20 . Every second row in the new 2×8 panel is either dedicated for TX or RX, and the connected TRX ICs supporting 2 transmitters and 2 receivers may be identical. The normal separation between antenna elements may be half the carrier wavelength, but may vary depending on side lobe requirements and physical constraints. For example, at higher frequencies (smaller wavelength), it may be infeasible to place a transceiver (TRX) behind each antenna. How to connect transmit and receive circuits of a transceiver to antennas is known by persons having ordinary skill in the art and is thus beyond the scope of this disclosure. In such cases, it may be useful to place dummy antennas in the array. This may result in undesirable higher sidelobes. As indicated by the bold arrows in  FIG.  2 A , there exist two adjacent IC interference paths from TX to RX causing self-interference. This may be difficult to suppress using analog cancelation on-chip and, given the short distance between the TX and nearby RX, the interference level can be severe. Note that, as shown in  FIG.  1   , in some embodiments, each element labeled TX may include a subarray of transmitters, and each element labeled RX may include a subarray of receivers. 
     Some embodiments are as shown in  FIG.  2 B .  FIG.  2 B  shows a panel  22  with transceiver ICs  24 ,  26 . Every other transceiver (TRX) IC  24  (or its connected antennas) is rotated approximately or exactly 180 degrees (or flipped horizontally, or mirrored) with respect to an adjacent TRX IC  26 . In other words, approximately 180 degrees can be exactly 180 degrees or substantially 180 degrees. For example, the TRX IC  24  may be rotated through an angle in the range of 175 to 185 degrees in some embodiments. In some embodiments the TRX IC  24  may be rotated through an angle in the range of 170 to 190 degree. In some embodiments the TRX IC  24  may be rotated through an angle in the range of 178 to 182 degrees. In other words, TRX IC  24  may be rotated with respect to the orientation of TRX IC  26 . This action does not change the overall footprint, and the antenna panel is still 2×8. However, adjacent IC interference is attenuated as compared with traditional solutions.  FIG.  2 B  shows that the number of nearest adjacent aggressors (A 1 , A 2 , A 3 , A 4 ) is double as compared to the original antenna interleaving layout shown in  FIG.  2 A . However, at the same time, the distance to the victim RX has also doubled. Since near field power rolls-off as one over distance raised to the fourth or higher, the TX aggressor power reaching the victim RX will be significantly reduced, even though there are more TX aggressors. 
     Advantages of configurations disclosed herein include greater receiver sensitivity, lower interference at receivers caused by transmissions from nearby transmitters (which are now further away), ease of design and manufacture, as well as scalability, as compared with other arrangements. 
     Aggressor power may increase by roughly 3 dB, whereas the pathloss increases by 6 dB and as it rolls off inversely proportional to the squared distance. Thus, a reduction of 3 dB compared to the original interleaving layout of  FIG.  2 A  is achieved by the layout of  FIG.  2 B . It should be noted that the antenna panels  22  may have a different shape, e.g., 8×2, and still benefit from the rotated layout. 
     When antenna panels are combined to form larger array structures, e.g., to increase the antenna directivity, the interference reduction effects are still present. An example is illustrated in  FIGS.  3 A and  3 B . In the layout of  FIG.  3 A , four nearby adjacent IC aggressors on adjacent panels  38  and  40  can be identified. However, when applying the arrangements shown in  FIG.  3 B , where the TRX ICs  24  of panel  42 ,  44  are flipped, rotated, or mirrored with respect to the TRX ICs  26  of panel  42 ,  44 . The number of nearby adjacent IC aggressors is reduced to one, as shown in  FIG.  3 B . This corresponds to a 75% power reduction, i.e., −6 dB, compared to the layout of  FIG.  3 A . Note that TRX ICs can be designed using any one of a number of semiconductor manufacturing technologies, such as GaAs, InP, GaN, Si, SiGe, or any combination of these. Also, there are many ways to connect ICs with the antenna. In one method, the antenna is integrated on the IC using the topmost metal layer(s). This may give poor antenna performance. Another approach is to design the antenna in the IC package, usually called an “antenna in package” solution. Another approach is to make a large antenna printed circuit board (PCB) and directly mount bare IC dies onto that. One way to do this is to package the ICs, and then mount the ICs on the antenna substrate. Note that the principles disclosed herein with respect to two adjacent panels  42 ,  44  readily extend to any number of adjacent panels. Also, the principles disclosed herein with respect to two adjacent TRX ICs  24 ,  26  readily extend to any number of adjacent transceivers ICs. 
     As is known, printed circuit boards are made of a dielectric material with a copper conductor layer on one or both sides. The dielectric may incorporate glass, ceramic, or other filler for improved electrical and mechanical stability. Antennas can be formed on one or both sides of the laminate or by using multiple layers of laminate materials. When more than one side is used, conductive layers are may be electrically connected by plated through holes (PTHs) in the insulator layer. 
     The antenna layout obtained by rotating every other radio IC (or its antennas) generates a different antenna pattern compared to an evenly spaced antenna element layout. When alternating between RX and TX for every other row, as in  FIG.  2 A , the vertical spacing between TX (or RX) elements becomes uniform. In the proposed layout, as seen in  FIG.  2 B , the spacing is not uniform. However, as the total array size is similar, the directivity is in both cases reduced by −3 dB in relation to the maximum aperture for the panel size, i.e., when connecting all elements to either RX or TX. The beam steering control (i.e., time delay or phase shift between antenna elements) should be different for the two layouts ( FIG.  2 A  versus  FIG.  2 B ), but in principle the same main lobe performance can be achieved. Note also that further isolation can be achieved by changing polarization between transmit and receive antenna elements. By changing the polarization between TX and RX antenna elements (or formed sub-arrays), the signal, distortion and noise coupling between these will change. This has an impact on the needed electrical isolation and the electrical cancelation performance between TX and RX to fulfil the overall required system isolation between TX and RX 
     In operation, it is contemplated that the antenna layout described here can, as a non-limiting example, be used in a cellular wireless communication system such as a wireless communication system compliant with a 3 rd  Generation Partnership Project (3GPP) set of standards. Such standards may include, but are not limited to Long Term Evolution (LTE) and New Radio (NR) (also known as 5G). It is further contemplated that the layout of TRX ICs described herein can be used in connection with a 3GPP network node, e.g., a base station, such as a gNB, eNB, etc. Such base stations have communication equipment that enable wireless communications with a plurality of wireless devices. Such communications are over the air on an RF channel via antennas. Antennas of the communications equipment may be connected to the transceiver ICs described herein. However, implementations are not limited to 3GPP-based networks. Further, additional components in the transmission and receive paths, e.g., power amplifiers, filters, etc., are not shown for ease of understanding. 
       FIG.  4    is a flowchart of an example process for grouping antenna elements to mitigate transmit to receive leakage in on-frequency full-duplex systems. The process includes arranging a row of transmit integrated circuits, ICs, and a row of receive ICs on an IC chip (Block S 10 ). The process further includes arranging a plurality of IC chips on a panel so that a row of receive circuits on one IC chip is adjacent to a row of receive circuits on an adjacent IC chip (Block S 12 ). 
       FIG.  5    is a flowchart of an example process for arranging TRX ICs on a printed circuit board. The process includes placing a first TRX IC on a printed circuit board, (Block S 14 ) and placing a second transceiver IC on the printed circuit board so that a first row of transmit circuits on the first transceiver IC is adjacent to a second row of transmit circuits on the second transceiver IC (Block S 16 ). 
     Thus, in some embodiments, a method to group antenna array elements to mitigate Tx-to-Rx leakage in on-frequency full-duplex systems is provided. In some embodiments, the Rx and Tx antennas with strongest unwanted coupling are all fed by the same transceiver (TRX) IC and analog cancellation methods can easily be applied to compensate the unwanted leakage. Receive (Rx) and transmit (Tx) antenna elements fed by different TRX ICs are moved further apart from each other in some embodiments, and will therefore have increased isolation and no need for analog cancellation loops between transceiver ICs. 
     Note that the configurations disclosed herein for orienting adjacent TRX ICs  24 ,  25 ,  26 ,  27  may produce different beam patterns than the beam patterns of conventionally oriented transceiver ICs. This is because the spacing between rows of transmit circuits  28 ,  34  is non-uniform in the configurations disclosed herein, whereas the spacing between rows of transmit circuits is uniform. However, the total array size in both cases are similar so that the respective directivity is reduced by −3 dB in relation to the maximum aperture given the panel size, i.e., when connecting all elements to either RX or TX. The beam steering control (i.e. time delay, or phase shift, between antenna element) will have to be different for the two layouts, but in principle the same main lobe performance can be achieved. 
     As mentioned, because there is non-uniform spacing of the transmit circuits, a different beam pattern may result as compared to the beam pattern generated with uniform spacing. In particular, exaggerated sidelobes may result, especially for large steering angles. For small steering angles, there can be expected only insignificant differences between beams resulting from non-uniform spacing and from uniform spacing. Also, there may be a variation between an azimuth cut of the beam and an elevation cut of the beam. For example, for the geometry of  FIG.  2 B or  3 B , where the element and subarray placement have a vertical orientation, the beam azimuth is little affected by the non-uniform spacing, whereas the beam elevation may have significant additional sidelobes or sidelobes that are more pronounced. 
     Because of non-uniform spacing, when a beam is steered away from boresight for example, between −10 and −30 degrees, reduction in beam gain may increase by as much as 2-3 dB. This reduction in gain may be offset by the reduction in path loss resulting from shorter distance between the base station and the wireless device(s) to which the beam is steered. For wireless devices on a cell boarder, maximum gain may compensate for the increased path loss between the based station and the wireless devices on the cell boarder. Note that the configurations disclosed herein may eliminate a need for analog cancellation loops between transceiver ICs. 
     According to one aspect, a communication apparatus to mitigate transmit to receive leakage in on-frequency full-duplex systems having a plurality of antenna elements is provided. The communication apparatus includes a panel  42  having transceiver integrated circuits, ICs  24  and  26 . The panel  42  includes a plurality of transceiver integrated circuits, ICs  24  and  26 , each transceiver IC  24 ,  26  having a row of transmit circuits  28 ,  34  and a row of receive circuits  30 ,  32 , the transceiver ICs  24  and  26  being arranged so that a row of receive circuits  30  on one transceiver IC  24  is adjacent to a row of receive circuits  32  on an adjacent transceiver IC  26 . 
     According to this aspect, in some embodiments, the communication apparatus further comprising a plurality of panels  42 ,  44 , the plurality of panels  42 ,  44  being arranged side by side so that a row of receive circuits  30  on a transceiver IC  24  on a first panel  42  is aligned with a row of receive circuits  30  on a transceiver IC  25  on a second panel  44 . In some embodiments, a plurality of transceiver ICs  24 ,  26  on the panel  42  are arranged by rotating every other transceiver IC  24 ,  26  so that rows of receive circuits  30  on one panel  42  are in a same row as a row of receive circuits  30  on an adjacent panel  44 . In some embodiments, the rotation is approximately 180 degrees. In some embodiments, a distance between adjacent transceiver ICs  24 ,  26  is less than a wavelength at a frequency of operation of the plurality of antenna elements. In some embodiments, the plurality of panels  42 ,  44  are arranged side by side so that a row of receive circuits  30  on a transceiver IC  24  on a first panel  42  is aligned with a row of receive circuits  30  of a transceiver IC  25  on a second panel  44 . In some embodiments, a distance between adjacent panels  42  and  44  is less than a wavelength at a frequency of operation of the plurality of antenna elements. 
     According to yet another aspect, a method for arranging transceiver integrated circuits, ICs,  24 ,  26  to mitigate transmit to receive leakage in on-frequency full-duplex systems having a plurality of antenna elements is provided. The method includes arranging a row of transmit circuits  28  and a row of receive circuits  30  on a transceiver IC  24 ; and arranging a plurality of transceiver ICs  24 ,  26  on a first panel  42  so that a row of receive circuits  30  on one transceiver IC  24  is adjacent to a row of receive circuits  32  on an adjacent transceiver IC  26 . 
     According to this aspect, in some embodiments, the method further includes arranging a plurality of panels  42 ,  44  side by side so that a row of receive circuits  30  on a transceiver IC  24  on the first panel  42  is aligned with a row of receive circuits  30  on a transceiver IC  25  on a second panel  44 . In some embodiments, the method further includes arranging a plurality of panels  42 ,  44  and arranging the plurality of transceiver ICs  24 ,  26  on the first panel  42  by rotating every other transceiver IC  24  so that rows of receive circuits  30  on the first panel  42  are in a same row as a row of receive circuits  30  on an adjacent panel  44  of the plurality of panels. In some embodiments, the rotation is approximately 180 degrees. In some embodiments, the method further includes arranging the plurality of panels  42 ,  44  side by side so that a row of receive circuits  30  on a transceiver IC  24  on a first panel  42  is aligned with a row of receive circuits of a transceiver IC  25  on a second panel  44 . In some embodiments, a distance between adjacent panels  42 ,  44  is less than a wavelength at a frequency of operation of the plurality of antenna elements. 
     According to another aspect, an array of transceiver integrated circuits, ICs,  24 ,  26  is configured to be in communication with an array of antenna elements, each transceiver IC  24 ,  26  having a row of receive circuits  30  and a row of transmit circuits  28 , transceiver ICs  24 ,  26  in the array of transceiver ICs  24 ,  26  being arranged so that a row of receive circuits  30  on one transceiver IC  24  is adjacent to a row of receive circuits  30  on an adjacent transceiver IC  26 . 
     According to this aspect, in some embodiments, two adjacent transceiver ICs  24 ,  26  are arranged so that a row of receive circuits  30  on one transceiver IC  24  are more distant to a row of transmit circuits  34  on the other adjacent transceiver IC  26  than to a row of receive circuits on the other adjacent transceiver IC  26 . In some embodiments, transceiver ICs  24 ,  25  are arranged in panels  42 ,  44  so that a row of receive circuits  30  on one panel  42  is in a same row as a row of receive circuits  30  on an adjacent panel  44 . In some embodiments, a distance between adjacent transceiver ICs  24  and  26  is less than a wavelength at a frequency of operation of at least one antenna in communication with one of the adjacent transceiver ICs  24 ,  26 . In some embodiments, a first transceiver IC  24  is rotated with respect to an orientation of a second transceiver IC  26  adjacent to the first transceiver IC  24 . 
     According to yet another aspect, a panel  42  of transceiver integrated circuits, ICs  24  is configured such that each transceiver IC  24  has a row of transmit circuits  28  and a row of receive circuits  30 , every other transceiver IC  24  in a plurality of rows of transceiver ICs on the panel  42  being rotated with respect to an adjacent transceiver IC  26  on the panel. 
     According to this aspect, in some embodiments, any two adjacent transceiver ICs  24 ,  26  on the panel  42  are arranged so that a row of receive circuits  30  on one transceiver IC  24  are more distant to a row of transmit circuits  34  on the other adjacent transceiver IC  26  than to a row of receive circuits  32  on the other adjacent transceiver IC  26 . 
     According to another aspect, a method of manufacturing a panel of transceiver integrated circuits, ICs,  24  for communication with a plurality of antenna elements is provided. The method includes placing a first transceiver IC  24  on a printed circuit board; and placing a second transceiver IC  26  on the printed circuit board so that a first row of receive circuits on the first transceiver IC  24  is adjacent to a second row of receive circuits on the second transceiver IC  26 . 
     According to this aspect, in some embodiments, the second transceiver IC  26  is placed such that the second transceiver IC  26  is rotated with respect to an orientation of the first transceiver IC  24 . In some embodiments, the second transceiver IC  26  is rotated by an angle in the range of 178 to 182 degrees. In some embodiments, the second transceiver IC  26  is rotated by an angle in the range of 170 to 190 degrees. In some embodiments, the second transceiver IC  26  is rotated by 180 degrees. In some embodiments, a distance between the first and second transceiver ICs  24 ,  26  are positioned to be less than a wavelength apart at a frequency of operation of the plurality of antenna elements. 
     According to one aspect, a method for grouping antenna elements to mitigate transmit to receive leakage in on-frequency full-duplex systems is provided. The method includes arranging a row of transmit integrated circuits, ICs,  28  and a row of receive circuits  30  on an IC chip  24 . The method also includes arranging a plurality of IC chips  24  on a panel  42  so that a row of receive circuits  30  on one IC chip  24  is adjacent to a row of receive circuits  32  on an adjacent IC chip  26 . 
     According to this aspect, in some embodiments, the method further includes, arranging a plurality of panels  42 ,  44  side by side. In some embodiments, a distance between adjacent IC chips  24 ,  26  is less than a wavelength at a frequency of operation of the group of antenna elements and a distance between adjacent panels  42 ,  44  is less than the wavelength. In some embodiments, the IC chips  24 ,  26  may be much smaller than the area of the antenna panel  42 ,  44  the IC chips are connected to. In such cases, it is contemplated that the IC chips  24 ,  26  may be separated by more than a wavelength at a frequency of operation. 
     According to another aspect, an array of transmit/receive integrated circuits, ICs, chips  24 ,  25 ,  26 ,  27  are arranged to feed a group of antennas. Each IC chip has a row of receive circuits  30 ,  32  and a row of transmit circuits  28 ,  34 . IC chips in the array are arranged so that a row of receive circuits  30  on one IC chip  24  is adjacent to a row of receive circuits  32  on an adjacent IC chip  26 . 
     According to this aspect, in some embodiments, the IC chips are arranged in panels  42 ,  44  spaced less than a wavelength apart at a frequency of operation of the group of antennas. In some embodiments, the rows of receive circuits  30  in one panel  42  are in a same row as a row of receive circuits  30  in an adjacent panel  44 . 
     Some embodiments include: 
     Embodiment A1. A method for grouping antenna elements to mitigate transmit to receive leakage in on-frequency full-duplex systems, the method comprising: 
     arranging a row of transmit integrated circuits, ICs, and a row of receive ICs on an IC chip; and 
     arranging a plurality of IC chips on a panel so that a row of receive circuits on one IC chip is adjacent to a row of receive circuits on an adjacent IC chip. 
     Embodiment A2. The method of Embodiment A1, further comprising arranging a plurality of panels side by side. 
     Embodiment A3. The method of Embodiment A2, wherein a distance between adjacent IC chips is less than a wavelength at a frequency of operation of the group of antenna elements and a distance between adjacent panels is less than the wavelength. 
     Embodiment B1. An array of transmit/receive integrated circuit, IC, chips arranged to feed a group of antennas, each IC chip having a row of receive circuits and a row of transmit circuits, IC chips in the array being arranged so that a row of receive circuits on one IC chip is adjacent to a row of receive circuits on an adjacent IC chip. 
     Embodiment B2. The array of Embodiment B1, wherein the IC chips are arranged in panels spaced less than a wavelength apart at a frequency of operation of the group of antennas. 
     Embodiment B3. The array of Embodiment B2, wherein the rows of receive circuits in one panel are in a same row as a row of receive circuits in an adjacent panel. 
     Abbreviation Explanation 
     IC Integrated circuit 
     RX Receive/receiver 
     TX Transmit/transmitter 
     TRX Transceiver 
     It will be appreciated by persons skilled in the art that the present embodiments are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.