Patent Publication Number: US-2022224013-A1

Title: Multi-layer patch antenna

Description:
The present application for patent is a continuation of patent application Ser. No. 16/147,232 entitled “MULTI-LAYER PATCH ANTENNA” filed Sep. 28, 2018, pending, and assigned to the assignee hereof and hereby expressly incorporated by reference herein. 
    
    
     BACKGROUND 
     Wireless communication devices are increasingly popular and increasingly complex. For example, mobile telecommunication devices have progressed from simple phones, to smart phones with multiple communication capabilities (e.g., multiple cellular communication protocols, Wi-Fi, BLUETOOTH® and other short-range communication protocols), supercomputing processors, cameras, etc. Wireless communication devices have antennas to support wireless communication over a range of frequencies. 
     As wireless communication technology evolves from, mobile communication devices may be configured to communicate using multiple millimeter-wave, e.g., above 25 GHz, beams. For example, 5G devices may be configured to operate in the 28 GHz band (26.5-29.5 GHz) and the 39 GHz band (37-40 GHz). Millimeter-wave receive (Rx) beams may align with a transmit (Tx) beam of a 5G base station, that may be referred to as a gNodeB, or gNB, or a WLAN access point, or other source of communication signals. The receive beams may be from a Pseudo-Omni (PO) codebook (i.e., the range and granularity of steering angles), with a relatively large beamwidth, or may be from a narrow codebook, with a relatively small beamwidth. To form beams of varying beamwidths (e.g., narrower beamwidth for data transmission), different antenna array element types and arrangements may be used. By changing radiator array element weights (signal amplitudes and/or input feed signal phases), beams can be steered to various different scan angles and/or switched between a PO beam and a narrower beam. 
     SUMMARY 
     An example of an antenna system includes: a patch radiator being electrically conductive and configured to radiate energy in a first frequency band and a second frequency band, different from the first frequency band; a parasitic patch radiator overlapping with the patch radiator, the parasitic patch radiator being electrically conductive and being configured to radiate energy in the first frequency band; and at least one parasitic element including a conductor sized and disposed relative to the parasitic patch radiator such that a combination of the parasitic patch radiator and the at least one parasitic element will radiate energy in the second frequency band. 
     Implementations of such a system may include one or more of the following features. A lowest frequency in the first frequency band is at least 10% higher than a highest frequency in the second frequency band. The at least one parasitic element includes at least one conductor disposed adjacent to each edge of the parasitic patch radiator. The parasitic patch radiator is square, configured to radiate energy in the first frequency band in at least one of two orthogonal polarizations, and centered relative to the patch radiator, and the at least one parasitic element is symmetrically disposed and configured relative to the parasitic patch radiator such that the combination of the parasitic patch radiator and the at least one parasitic element will radiate energy in the second frequency band in at least one of the two orthogonal polarizations. The at least one parasitic element further includes a further conductor disposed is a region diagonally adjacent each corner of the parasitic patch radiator. The at least one parasitic element includes a conductive loop disposed around the parasitic patch radiator. 
     Also or alternatively, implementations of such a system may include one or more of the following features. The patch radiator is disposed in a first layer of the system, and the parasitic patch radiator and the at least one parasitic element are disposed in a second layer of the system, different from the first layer of the system. The parasitic patch radiator is a first parasitic patch radiator, the system further includes a second parasitic patch radiator disposed in a third layer of the system, the third layer being different from the first layer and the second layer, and the second parasitic patch radiator being configured to radiate energy in the second frequency band. The first parasitic patch radiator is disposed on a first side of the patch radiator and the second parasitic patch radiator is disposed on a second side, and overlapping with, the patch radiator. The system includes a plurality of parasitic elements, where the parasitic patch radiator and the plurality of parasitic elements are disposed symmetrically about a center point. The patch radiator is one of a plurality of patch radiators disposed in an array, the parasitic patch radiator and the at least one parasitic element are components of the array configured and disposed to parasitically couple to the plurality of patch radiators, and there are more parasitic patches than patch radiators in the array. 
     An example of a multi-layer antenna system includes: a multi-layered circuit board; a feed line configured to convey electricity; a patch radiator coupled to the feed line, the patch radiator being electrically conductive, having a rectangular shape, being disposed in a first layer of the multi-layered circuit board, and being configured to radiate energy in a first frequency band and a second frequency band different from the first frequency band; a parasitic patch radiator disposed in a second layer of the multi-layered circuit board, the patch radiator and the parasitic patch radiator overlapping, the parasitic patch radiator being electrically conductive, having a rectangular shape, having a first edge, a second edge, a third edge, and a fourth edge, each of the third edge and the fourth edge extending between the first edge and the second edge and having a first electrical length between 0.4 and 0.6 wavelengths, in a substrate of the multi-layered circuit board, in the first frequency band; and at least one parasitic element including a first conductor disposed adjacent to the first edge of the parasitic patch radiator and a second conductor disposed adjacent to the second edge of the parasitic patch radiator. 
     Implementations of such a system may include one or more of the following features. The parasitic patch radiator and the at least one parasitic element are disposed and configured to, in combination, provide an electrical length between 0.4 and 0.6 wavelengths in the substrate in the second frequency band to radiate energy in the second frequency band, a lowest frequency in the first frequency band being at least 10% higher than a highest frequency in the second frequency band. The parasitic patch radiator is square, the at least one parasitic element further includes a third conductor disposed adjacent to the third edge of the patch radiator and a fourth conductor disposed adjacent to the fourth edge of the patch radiator, the parasitic patch radiator, the first conductor, and the second conductor are configured to, in combination, radiate energy in the second frequency band in a first polarization, and the parasitic patch radiator, the third conductor, and the fourth conductor are configured to, in combination, radiate energy in the second frequency band in a second polarization orthogonal to the first polarization. 
     Also or alternatively, implementations of such a system may include one or more of the following features. The at least one parasitic element includes at least four conductive strips each disposed adjacent to a respective one of the first, second, third, and fourth edges of the parasitic patch radiator. The at least one parasitic element further includes square conductors each aligned with two of the four conductive strips. 
     Also or alternatively, implementations of such a system may include one or more of the following features. The at least one parasitic element includes a conductive ring disposed around the parasitic patch radiator. The parasitic patch radiator is a first parasitic patch radiator, and the system further includes a second parasitic patch radiator disposed in a third layer of the multi-layered circuit board and configured to radiate energy in the second frequency band. The at least one parasitic element is disposed in the second layer of the multi-layered circuit board. 
     Another example of an antenna system includes: a multi-layered circuit board; a feed line configured to convey electricity; a patch radiator coupled to the feed line, the patch radiator being electrically conductive, being disposed in a first layer of the multi-layered circuit board, and being configured to radiate energy at a first frequency and at a second frequency, the first frequency and the second frequency being separated by more than 5 GHz; and a plurality of parasitic patches disposed in a second layer of the multi-layered circuit board, the plurality of parasitic patches configured to receive first energy at the first frequency from the patch radiator and to re-radiate at least a portion of the first received energy at the first frequency, and configured to receive second energy at the second frequency from the patch radiator and to re-radiate at least a portion of the second received energy at the second frequency. 
     Implementations of such a system may include one or more of the following features. The plurality of parasitic patches are symmetric about a center point. The plurality of parasitic patches include four square patches each partially overlapping the patch radiator. The center point is a center point of the patch radiator. The first frequency is separated from the second frequency by approximately 11 GHz. 
     Another example of an antenna system includes: feed means for providing a first signal in a first frequency band and a second signal in a second frequency band; first radiating means, electrically coupled to the feed means, for radiating, in the first frequency band, the first signal received from the feed means, and for radiating, in the second frequency band, the second signal received from the feed means; second radiating means for parasitically receiving the first signal from the first radiating means and radiating, in the first frequency band, the first signal in the first frequency band; and third radiating means for parasitically receiving, in combination with the second radiating means, the second signal in the second frequency band and for radiating, in combination with the second radiating means, the second signal in the second frequency band. 
     Implementations of such a system may include one or more of the following features. The third radiating means are for parasitically receiving, in combination with the second radiating means, the second signal in the second frequency band from the first radiating means. A lowest frequency in the first frequency band is at least 10% higher than a highest frequency in the second frequency band. The second radiating means and the third radiating means are disposed in a first layer of a multi-layer circuit board. The system may include fourth radiating means for parasitically receiving the second signal in the second frequency band from the first radiating means and for radiating the second signal in the second frequency band, where the fourth radiating means are disposed in a second layer, different from the first layer, of the multi-layer circuit board. The second radiating means are for radiating the first signal in two orthogonal polarizations, and the third radiating means are symmetrically disposed about the second radiating means and are for, in combination with the second radiating means, radiating the second signal in the two orthogonal polarizations. 
     An example of a dual-band, dual-polarization antenna system includes: a multi-layered circuit board; a plurality of feed lines configured to convey electricity; a patch radiator coupled to the plurality of feed lines, the patch radiator being electrically conductive, having a square shape, being disposed in a first layer of the multi-layered circuit board, and shaped to radiate energy in a first frequency band of different polarizations in response to receiving energy in the first frequency band from the plurality of feed lines and shaped to radiate energy in a second frequency band of different polarizations in response to receiving energy in the second frequency band from the plurality of feed lines, the second frequency band being different from the first frequency band; a parasitic patch radiator disposed in a second layer of the multi-layered circuit board, the patch radiator and the parasitic patch radiator overlapping, the parasitic patch radiator being electrically conductive, and having a square shape with each edge having a length between 0.4 wavelengths and 0.6 wavelengths of energy in the first frequency band in the multi-layered circuit board; and at least one parasitic element disposed in the second layer of the multi-layered circuit board, the at least one parasitic element comprising conductive material disposed adjacent to at least two orthogonal edges of the patch radiator; where a cumulative length of the patch radiator and the at least one parasitic element, measured parallel to any edge of the parasitic patch radiator, is between 0.4 wavelengths and 0.6 wavelengths of energy in the second frequency band in the multi-layered circuit board. 
     Implementations of such a system may include one or more of the following features. A lowest frequency in the first frequency band is at least 10% higher than a highest frequency in the second frequency band. The at least one parasitic element includes at least four conductive strips each disposed adjacent to a respective edge of the parasitic patch radiator. The at least one parasitic element further includes square conductors each aligned with two of the four conductive strips. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a communication system. 
         FIG. 2  is an exploded perspective view of simplified components of a mobile device shown in  FIG. 1 . 
         FIG. 3  is a top view of a printed circuit board, shown in  FIG. 2 , including antennas. 
         FIG. 4  is a top view of an example patch radiator system shown in  FIG. 3 . 
         FIG. 5  is a side view of the patch radiator system shown in  FIG. 4 . 
         FIG. 6  is a top view of an alternative patch radiator system with a loop parasitic element. 
         FIGS. 7-8  are top views of further alternative patch radiator systems with further parasitic elements. 
         FIG. 9  is a side view of another example patch radiator system. 
         FIG. 10  is a top view of the patch radiator system shown in  FIG. 9 . 
         FIG. 11  is a block flow diagram of a method of parasitically receiving and re-radiating signals of different frequency bands. 
     
    
    
     DETAILED DESCRIPTION 
     Techniques are discussed herein for arranging non-radiating metal in a multi-layer antenna. For example, a patch antenna may be driven different frequency signals, and may be driven to radiate in multiple polarizations, e.g., two polarizations for each different frequency signal. For example, a patch antenna may be driven with a horizontal polarization signal (on H-pol feed) and a vertical polarization signal (on V-pol feed), both in a lower frequency (e.g., a 28 GHz band) and in a higher frequency (e.g., a 39 GHz band). The driven patch radiates energy in the lower frequency and the higher frequency in both polarizations, and at least the energy in the higher frequency couples to a parasitic patch radiator that is disposed in a different layer than the patch antenna and that overlaps the patch antenna. The parasitic patch radiator receives the energy of the higher frequency from the patch antenna and re-radiates the energy at the higher frequency. At least one parasitic element is configured (e.g., sized, shaped, etc.) and disposed to work in conjunction with the parasitic patch radiator to receive energy of the lower frequency from the patch antenna and re-radiate energy of the lower frequency. For example, the parasitic patch radiator may be resonant at the higher frequency and the parasitic patch radiator in combination with the at least one parasitic element is resonant at the lower frequency. Other configurations, however, may be used. 
     Items and/or techniques described herein may provide one or more of the following capabilities, as well as other capabilities not mentioned. Multiple bands of signals may be radiated using a compact antenna configuration, e.g., using a radiating patch antenna in conjunction with a parasitic patch radiator and at least one parasitic element. Signals in multiple millimeter-wave frequency bands may be radiated from a thin, multi-layered antenna structure. A parasitic patch radiator may be resonant in one frequency band and may form a portion of a radiator that is resonant in a different frequency band. Bandwidth may be broadened in one or more bands, e.g., in one or more millimeter-wave bands (e.g., 28 GHz band and 39 GHz band) compared to other antenna configurations. Other capabilities may be provided and not every implementation according to the disclosure must provide any, let alone all, of the capabilities discussed. Further, it may be possible for an effect noted above to be achieved by means other than that noted, and a noted item/technique may not necessarily yield the noted effect. 
     Referring to  FIG. 1 , a communication system  10  includes mobile devices  12 , a network  14 , a server  16 , and access points (APs)  18 ,  20 . The system  10  is a wireless communication system in that components of the system  10  can communicate with one another (at least some times using wireless connections) directly or indirectly, e.g., via the network  14  and/or one or more of the access points  18 ,  20  (and/or one or more other devices not shown, such as one or more base transceiver stations). For indirect communications, the communications may be altered during transmission from one entity to another, e.g., to alter header information of data packets, to change format, etc. The mobile devices  12  shown are mobile wireless communication devices (although they may communicate wirelessly and via wired connections) including mobile phones (including smartphones), a laptop computer, and a tablet computer. Still other mobile devices may be used, whether currently existing or developed in the future. Further, other wireless devices (whether mobile or not) may be implemented within the system  10  and may communicate with each other and/or with the mobile devices  12 , network  14 , server  16 , and/or APs  18 ,  20 . For example, such other devices may include internet of thing (IoT) devices, medical devices, home entertainment and/or automation devices, etc. The mobile devices  12  or other devices may be configured to communicate in different networks and/or for different purposes (e.g., 5G, Wi-Fi communication, multiple frequencies of Wi-Fi communication, satellite positioning, one or more types of cellular communications (e.g., GSM (Global System for Mobiles), CDMA (Code Division Multiple Access), LTE (Long-Term Evolution), etc.). The mobile device  12  is commonly referred to as a user equipment (UE) in UMTS (Universal Mobile Telecommunications System) applications, but may also be referred to as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. 
     Referring to  FIG. 2 , an example of one of the mobile devices  12  shown in  FIG. 1  includes a top cover  52 , a display layer  54 , a printed circuit board (PCB) layer  56 , and a bottom cover  58 . The mobile device  12  as shown may be a smartphone or a tablet computer but the discussion is not limited to such devices. The top cover  52  includes a screen  53 . The PCB layer  56  includes one or more antennas configured to facilitate bi-directional communication between mobile device  12  and one or more other devices, including other wireless communication devices. The bottom cover  58  has a bottom surface  59  and sides  51 ,  57  of the top cover  52  and the bottom cover  58  provide an edge surface. The top cover  52  and the bottom cover  58  may comprise a housing that retains the display layer  54 , the PCB layer  56 , and other components of the mobile device  12  that may or may not be on the PCB layer  56 . For example, the housing may retain (e.g., hold, contain) antenna systems, front-end circuits, an intermediate-frequency circuit, and a processor discussed below. Further, the size and/or shape of the PCB layer  56  may not be commensurate with the size and/or shape of either of the top or bottom covers or otherwise with a perimeter of the device. For example, the PCB layer  56  may have a cutout to accept a battery. Those of skill in the art will therefore understand that embodiments of the PCB layer  56  other than those illustrated may be implemented. 
     Referring also to  FIG. 3 , an example of the PCB layer  56  includes a main portion  60  and two antenna systems  62 ,  64 . In the example shown, the antenna systems  62 ,  64  are disposed at opposite ends  63 ,  65  of the PCB layer  56 , and thus, in this example, of the mobile device  12  (e.g., of the housing of the mobile device  12 ). The main portion  60  may comprise a PCB  66  that includes front-end circuits  70 ,  72  (also called a radio frequency (RF) circuit), an intermediate-frequency (IF) circuit  74 , and a processor  76 . The front-end circuits  70 ,  72  are configured to provide signals to be radiated to the antenna systems  62 ,  64  and to receive and process signals that are received by, and provided to the front-end circuits  70 ,  72  from, the antenna systems  62 ,  64 . The front-end circuits  70 ,  72  are configured to convert received IF signals from the IF circuit  74  to RF signals (amplifying with a power amplifier as appropriate), and provide the RF signals to the antenna systems  62 ,  64  for radiation. The front-end circuits  70 ,  72  are configured to convert RF signals received by the antenna systems  62 ,  64  to IF signals (e.g., using a low-noise amplifier and a mixer) and to send the IF signals to the IF circuit  74 . The IF circuit  74  is configured to convert IF signals received from the front-end circuits  70 ,  72  to baseband signals and to provide the baseband signals to the processor  76 . The IF circuit  74  is also configured to convert baseband signals provided by the processor  76  to IF signals, and to provide the IF signals to the front-end circuits  70 ,  72 . The processor  76  is communicatively coupled to the IF circuit  74 , which is communicatively coupled to the front-end circuits  70 ,  72 , which are communicatively coupled to the antenna systems  62 ,  64 , respectively. 
     The antenna systems  62 ,  64  may be formed as part of the PCB layer  56  in a variety of manners. In  FIG. 3 , dashed lines  71 ,  73  separating the antenna systems  62 ,  64  from the PCB  66  indicate functional separation of the antenna systems  62 ,  64  (and the components thereof) from other portions of the PCB layer  56 . The antenna systems  62 ,  64  may be integral with the PCB  66 , being formed as integral components of the PCB  66  or may be separate from, but attached to, the PCB  66 . Alternatively, one or more components of the antenna system  62  and/or the antenna system  64  may be formed integrally with the PCB  66 , and one or more other components may be formed separate from the PCB  66  and mounted to the PCB  66 , or otherwise made part of the PCB layer  56 . Alternatively, each of the antenna systems  62 ,  64  may be formed separately from the PCB  66  and mounted to the PCB  66  and coupled to the front-end circuits  70 ,  72 , respectively. In some embodiments, one or both of the front-end circuits  70 ,  72  are implemented with the antenna system  62  or  64  in a module and coupled to the PCB  66 . For example, the module may be mounted to the PCB  66  or may be spaced from the PCB  66  and coupled thereto, for example using flexible cable or a flexible circuit. The antenna systems  62 ,  64  may be configured similarly to each other or differently from each other. For example, one or more components of either of the antenna systems  62 ,  64 , may be omitted. As an example, the antenna system  62  may include 4G and 5G radiators while the antenna system  64  may not include (may omit) a 5G radiator. In other examples, an entire one of the antenna systems  62 ,  64  may be omitted or may be configured for use with a non-cellular technology such as a WLAN technology. 
     A display  61  (see  FIG. 2 ) of the display layer  54  may roughly cover the same area as the PCB  66  and serve as a system ground plane for the antenna systems  62 ,  64  (and possibly other components of the device  12 ). The display  61  is disposed below the antenna system  62  and above the antenna system  64  (with “above” and “below” being relative to the mobile device  12 , i.e., with a top of the mobile device  12  being above other components regardless of an orientation of the device  12  relative to the Earth). 
     The antenna systems  62 ,  64  may be configured to transmit and receive millimeter-wave energy. The antenna systems  62 ,  64  may be configured to steer to different scan angels and/or to change size of beamwidth, e.g., between a PO beam and a narrower beam. 
     Here, the antenna systems  62 ,  64  are configured similarly, with multiple radiators to facilitate communication with other devices at various directions relative to the mobile device  12 . In the example of  FIG. 3 , the antenna system  62  includes an array  80  of patch radiator systems and an array  82  of dipole radiators. In other examples, one or more antenna systems may include one or more dipole radiators only, one or more patch radiators only, or a combination of one or more diploe radiators and one or more patch radiators. In other examples, one or more other types of radiators may be used alone or in combination with one or more dipole radiators and/or one or more patch radiators. The patch radiators are configured to radiate signals primarily to, and receive signals primarily from, above and below a plane of the PCB layer  56 , i.e., into and out of the page showing  FIG. 3 . The dipole radiators are configured to radiate signals primarily to, and receive signals primarily from, sides of the PCB layer  56 , with the dipole radiators in the antenna system  62  configured to radiate primarily to the top and left of the PCB layer  56  as shown in  FIG. 3  and the dipole radiators in the antenna system  64  configured to radiate primarily to the right and bottom of the PCB layer  56  as shown in  FIG. 3 . Positioning the antenna systems  62 ,  64  in or near corners of the PCB layer  56  may help provide spatial diversity (directions relative to the mobile device  12  to which signals may be transmitted and from which signals may be received), e.g., to help increase MIMO (Multiple Input, Multiple Output) capability. Further, the array  82  of patch radiators may be configured to provide dual polarization radiation and reception. 
     Referring also to  FIGS. 4-5 , an example of a patch radiator system  110 , of the array  80  of patch radiator systems of the antenna system  62  shown in  FIG. 3 , is shown, with  FIG. 4  being a top view of the system  110  and  FIG. 5  being a side view of the system  110 . The patch radiator system  110  includes a multi-layered circuit board  111  that includes a high-band patch  112 , parasitic elements  114 ,  115 ,  116 ,  117 , a radiating patch  118 , a low-band patch  120 , a horizontal polarization feed  122 , a vertical polarization feed  124 , a ground plane  128 , and a substrate  130 . The parasitic elements  114 - 117  may be considered as parasitic patches. The patch radiator system  110  is configured as a dual-band, dual-polarization radiator system. Being configured for dual-polarization radiation is not required, and one or more features in the system  110  may instead be configured to single-polarization radiation (e.g., a single feed may be used and/or one or more patches or other items sized and shaped for single polarization radiation at the frequency of signals to be transmitted and/or received). In the example shown, however, items are configured and provided for dual-polarization radiation. In particular, the system  110  may radiate in either or both of two orthogonal polarizations for two different 5G communication bands, e.g., due to orthogonal edges of radiators (e.g., patch radiators, parasitic radiators). For example, the system  110  may be configured to radiate in different, here orthogonal, polarizations in both the 28 GHz band and the 39 GHz band. In  FIG. 5 , the parasitic element  117  is not shown for clarity. The radiating patch  118 , the low-band patch  120 , and the ground plane  128  are disposed in different layers in the system within the substrate  130 . The high-band patch  112  and the parasitic elements  114 - 117  are disposed in the same layer of the system  110 , here, on top of the substrate  130 . As shown in  FIG. 5 , with the system  110  oriented as shown, the high-band patch  112  is disposed above the radiating patch  118  (i.e., on a side of the patch  118  opposite the ground plane  128 ) and the low-band patch  120  is disposed below the radiating patch  118  (i.e., on the same side of the radiating patch  118  as the ground plane  128 , such that the low-band patch  120  is disposed between the radiating patch  118  and the ground plane  128 ). 
     The feeds  122 ,  124  (also referred to as feed lines) are configured to convey electricity to provide signals to the radiating patch  118 . Each of the feeds  122 ,  124  is configured to provide signals of different frequencies, here in the 28 GHz and 39 GHz band to the radiating patch  118 . The feeds  122 ,  124  are electrically coupled to the radiating patch  118  in appropriate locations to excite the radiating patch  118  to radiate respective polarizations of signals in response to receiving signals from the feeds  122 ,  124 . Here, the horizontal polarization feed  122  is coupled to the radiating patch  118  to excite the radiating patch  118  to radiate horizontally-polarized signals of frequencies corresponding to the frequencies of the energy of the signals provided by the feed  122 . Also, the vertical polarization feed  124  is coupled to the radiating patch  118  to excite the radiating patch  118  to radiate vertically-polarized signals of frequencies corresponding to the frequencies of the energy of the signals provided by the feed  124 . The feeds  122 ,  124  receive signals to be provided to the radiating patch  118  from transmission lines, e.g., striplines with the ground plane  128  being a top portion of the striplines (with remaining portions not shown). The feeds pass through, and do not make electrical contact with, the low-band patch  120 . 
     The radiating patch  118  is electrically conductive (e.g., a conductor made of electrically conductive material), electrically coupled to the feeds  122 ,  124 , and configured to radiate signals received from the feeds  122 ,  124 . There may be some loss of some of the energy in a signal received from either of the feeds  122 ,  124  during transmission, but the radiating patch  118  will radiate sufficient energy to convey a signal corresponding to the information received, i.e., characteristics of the radiated signal will correspond to characteristics of the received signal. As shown, the radiating patch  118  is rectangular, here square, such that the radiating patch  118  may radiate signals in either or both of two orthogonal polarizations from respective edges of the radiating patch  118 . The radiating patch  118  is sized to radiate energy in a high frequency band, e.g., and the 39 GHz band (37-40 GHz). For example, each edge of the radiating patch  118  may have an electrical length between 0.4 and 0.6 wavelengths, in the substrate  130 , in the 39 GHz band. Here the edges of the radiating patch  118  are straight, but other configurations may be used (e.g., with slots extending inwardly from an otherwise straight edge). The radiating patch  118  is also configured to couple energy in a low frequency band, e.g., the 28 GHz band (26.5-29.5 GHz) to the low-band patch  120 . A lowest frequency in the high frequency band may be at least 10% higher than a highest frequency in the low frequency band. 
     The high-band patch  112  is electrically conductive and configured and disposed to parasitically receive a high-band signal in a high frequency band and to re-radiate the high-band signal in the high frequency band (e.g., the 39 GHz band). The high-band patch  112  may be called a parasitic patch. The high-band patch  112  parasitically receives the high-band signal from the radiating patch  118  in that the high-band patch  112  wirelessly couples to and receives the high-band signal from energy radiated by the radiating patch  118 . The high-band patch  112  re-radiates one or more signals in response to receiving the one or more signals from the radiating patch  118 . The re-radiated high-band signal may have less energy than the received high-band signal but remains the same signal in content. The high-band patch  112  is disposed overlapping the radiating patch  118  to facilitate reception by the high-band patch  112  of the high-band signal radiated by the radiating patch  118 . As shown, the high-band patch  112  is centered over the radiating patch  118 , with edges  113  of the high-band patch  112  parallel with edges  119  of the radiating patch  118 , and the entire high-band patch  112  overlaps the radiating patch  118 , although other arrangements may be used (e.g., only partially overlapping the radiating patch  118 , the edges  113  of the high-band patch  112  not parallel to the edges  119  of the patch  118 , etc.). The high-band patch  112  is rectangular, here square, with edge lengths sized for radiating signals in the high band, e.g., in the 39 GHz band. The high-band patch  112  has edge lengths  131  that are slightly smaller than edge lengths  133  of the radiating patch  118 , which may thus better (e.g., more efficiently) radiate signals in the high band than the radiating patch  118 . The electrical length, here the edge length  131 , of each edge of the high-band patch  112  may be between 0.4 and 0.6 wavelengths, in the substrate  130 , of the frequencies in the high frequency band. Here, the edges of the high-band patch  112  are straight and thus the physical length corresponds to the electrical length. Other configurations, however, may be used, e.g., with one or more non-straight edges (e.g., with slots extending inwardly from an edge). Other examples of high-band patches may not be square, e.g., being rectangular but with two different edge lengths. This may facilitate radiation in different frequency bands. 
     The parasitic elements  114 - 117  are configured and disposed to parasitically receive a low-band signal in combination with the high-band patch  112 . That is, the parasitic elements  114 - 117  are configured and disposed such that the combination of the high-band patch  112  and the parasitic elements  114 - 117  will parasitically receive the low-band signal (in a low frequency band) from the radiating patch  118 . While four parasitic elements are shown, this is an example and other quantities (e.g., one, two, three, or more than four) of parasitic elements may be used. The combination of the high-band patch  112  and the parasitic elements  114 - 117  is configured to re-radiate the low-band signal in the low frequency band (e.g., the 28 GHz band). The combination of the high-band patch  112  and the parasitic elements  114 - 117  re-radiates one or more signals in response to receiving the one or more signals from the radiating patch  118 . The combination of the high-band patch  112  and the parasitic elements  114 - 117  parasitically receives the low-band signal from the radiating patch  118  in that the high-band patch  112  and the parasitic elements  114 - 117  are not physically coupled to the radiating patch  118  (or either of the feeds  122 ,  124 ), but wirelessly couples to and receives the low-band signal from energy radiated by the radiating patch  118 . The re-radiated low-band signal may have less energy than the received low-band signal but remains the same signal in content. 
     Each of the parasitic elements  114 - 117  is disposed adjacent to, i.e., near but a non-zero distance from, a corresponding edge of the high-band patch  112 . An amount of separation between the high-band patch  112  and each of the parasitic elements  114 - 117  may be selected to provide desired performance of the system  110 . The separation selected may be a tradeoff between low-band performance and high-band performance (e.g., return loss), with smaller separations increasing low-band performance and decreasing high-band performance and larger separations increasing high-band performance and decreasing low-band performance. In the example shown in  FIGS. 4-5 , the separation between the high-band patch  112  and the parasitic elements  114 - 117  is enough that the parasitic elements  114 - 117  do not overlap with the radiating patch  118 , but is small enough that the parasitic elements  114 - 117  do overlap partially with the low-band patch  120 . This separation is an example only and other separations may be used. The parasitic elements  114 - 117  are symmetrically disposed about the radiating patch  118  in the example shown in  FIGS. 4-5 . Also, in the example shown in  FIGS. 4-5 , the parasitic elements  114 - 117  have lengths that are slightly longer than the lengths of the corresponding edges of the high-band patch  112 . Alternatively, the parasitic elements  114 - 117  could have the same lengths as the corresponding edges of the high-band patch  112 , with ends of the parasitic elements  114 - 117  being collinear with respective edges of the high-band patch  112 . In this example shown in  FIGS. 4-5 , the parasitic elements  114 - 117  are all separated from the high-band patch  112  by the same amount and have equal widths, although other configurations (e.g., unequal separations and/or unequal widths) could be used. 
     The parasitic elements  114 - 117  are sized and shaped to help parasitically receive and re-radiate signals in the low frequency band. Each of the parasitic elements  114 - 117  has an electrical width (in this example, a width  132 ) such that a combined distance of the electrical width (here, of the width  132 ) of two of the parasitic elements  114 - 117  and the electrical length (here, the length  131 ) of a corresponding edge of the high-band patch  112  between the two parasitic elements  114 - 117  is about half of a wavelength of the low-band signal. For example, this distance (here, a cumulative length of the length  131  plus twice the width  132 ) may be between 0.4 and 0.6 wavelengths, in the substrate  130 , of the frequencies in the low frequency band. 
     The low-band patch  120  is configured and disposed to parasitically receive the low-band signal in the low frequency band and re-radiate the low-band signal in the low frequency band. The low-band patch  120  is thus a parasitic patch. The low-band patch  120  parasitically receives the low-band signal from the radiating patch  118  in that the low-band patch  120  is not conductively coupled to radiating patch  118  (or either of the feeds  122 ,  124 ), but wirelessly couples to and receives the low-band signal from energy radiated by the radiating patch  118 . The re-radiated low-band signal from the low-band patch  120  may have less energy than the received low-band signal but remains the same signal in content. The re-radiated low-band signal from the low-band patch  120  may be received and re-radiated by the combination of the high-band patch  112  and the parasitic elements  114 - 117 . The low-band patch  120  is disposed overlapping the radiating patch  118  to facilitate reception by the low-band patch  120  of the low-band signal radiated by the radiating patch  118 . As shown, the low-band patch  120  is centered over the radiating patch  118 , with edges  121  of the low-band patch  120  parallel with the edges  119  of the radiating patch  118 , and the entire radiating patch  118  being overlapped by the low-band patch  120 , although other arrangements may be used (e.g., only partially overlapping the radiating patch  118 , the edges  121  of the low-band patch  120  not parallel to the edges  119  of the patch  118 , etc.). In this example, the low-band patch  120  is rectangular, here square, with electrical edge lengths sized for radiating signals in the low band, e.g., in the 28 GHz band. The low-band patch  120  has electrical edge lengths, here edge lengths  134 , that are longer than the electrical edge lengths, here the edge lengths  133 , of the radiating patch  118 , which may thus better (e.g., more efficiently) radiate signals in the low band than the radiating patch  118 . The electrical edge length of each edge of the low-band patch  120  may be between 0.4 and 0.6 wavelengths, in the substrate  130 , of the frequencies in the low frequency band. Other examples of low-band patches may not be square, e.g., being rectangular but with two different edge lengths. This may facilitate radiation in different frequency bands. 
     Other Configurations 
     The examples discussed above are non-exhaustive examples and numerous other configurations may be used. The discussion below is directed to some of such other configurations, but is not exhaustive either (by itself or when combined with the discussion above). 
     Other configurations of parasitic elements or a parasitic element may be used. Referring to  FIG. 6 , an example of a patch radiator system  150 , of the array  80  of patch radiator systems of the antenna system  62  shown in  FIG. 3 , includes a high-band patch  152  and a single parasitic element  154 , with  FIG. 6  being a top view of the system  150 . The system  150  includes a radiating patch and may include other features (e.g., a low-band patch) similar to the system  110  shown in  FIGS. 4-5 ), but these features are not shown in  FIG. 6  for simplicity of the figure. The system  150  includes the single parasitic element  154  instead of the parasitic elements  114 - 117  shown in  FIG. 4 . The parasitic element  154  is a loop disposed around the high-band patch  152 . Here, the loop is a square conductive ring although other shapes may be used. 
     Referring to  FIG. 7 , which is a top view, another example of a patch radiator system  160  includes the high-band patch  112 , the parasitic elements  114 ,  115 ,  116 ,  117 , the radiating patch  118 , the low-band patch  120 , the horizontal polarization feed  122 , and the vertical polarization feed  124  as shown in  FIG. 4 , and also includes further parasitic elements  164 ,  165 ,  166 ,  167 . The parasitic elements  164 - 167  are disposed diagonally adjacent to the high-band patch  112  in corners of the system  160 , with each of the parasitic elements  164 - 167  aligned with two of the parasitic elements  114 - 117  that are, here, conductive strips. The use of the parasitic elements  164 - 167  may further improve radiation (e.g., lower insertion loss compared to not using the parasitic elements  164 - 167 ) by the system  160  in a lower frequency band, e.g., where a quarter wavelength in the lower frequency band is about equal to a width of the high-band patch  112  and two widths of one of the parasitic elements  114 - 117 . In this example, the further parasitic elements  164 - 167  are square conductors. Using parasitic elements may also improve impedance match from the feeds into the radiating patch. 
     Referring to  FIG. 8 , which is a top view, another example of a patch radiator system  170  includes a parasitic patch  172 , parasitic elements  174 ,  175 ,  176 ,  177 , a radiating patch  178 , a horizontal polarization feed  180 , a vertical polarization feed  182 , and further parasitic elements  184 ,  185 ,  186 ,  187 . In this example, the parasitic elements  174 - 177  are conductive strips each disposed in close proximity with a respective edge of the parasitic patch  172  and each having a length similar (here, equal) to the length of the respective edge of the parasitic patch  172 . Each of the parasitic elements  184 - 187  is disposed in a respective corner of the system  170  and aligned with a respective pair of the parasitic elements  174 - 177 . The parasitic patch  172  is smaller than the radiating patch  178 . The radiating patch  178  completely overlaps the parasitic patch  172 , partially overlaps each of the parasitic elements  174 - 177 , and partially overlaps each of the parasitic elements  184 - 187 . The parasitic patch  172  is sized to radiate energy primarily in a desired frequency band (e.g., has electrical edge lengths between 0.4 wavelengths and 0.6 wavelengths, in a substrate of the system  170 , of frequencies in the desired frequency band). The parasitic elements  174 - 177 ,  184 - 187  are sized, shaped, and disposed such that a combination of the parasitic patch  172  and the parasitic elements  174 - 177 ,  184 - 187  re-radiate energy received from the radiating patch  178  primarily in the desired frequency band. 
     Still other configurations are possible. For example, in the patch radiator system  170 , and/or in other configurations, a low-band patch (such as the low-band patch  120  shown in  FIGS. 4-5 ) may be omitted. 
     Referring to  FIGS. 9 and 10 , which are side and top views, respectively, another example of a patch radiator system  210  includes a radiating patch  212 , parasitic patches  214 ,  215 ,  216 ,  217 , a feed  220 , a substrate  222 , and a ground plane  224 . In this example, the radiating patch  212  may be configured to radiate signals, provided through the feed  220 , of multiple frequency bands or of multiple frequencies across a wide band, for example a band of 5 GHz or more (e.g., 11 GHz). Here, each of the parasitic patches  214 - 217  is square, and there are four parasitic patches, although other shapes (e.g., non-square rectangles, hexagons, etc.) and/or quantities of parasitic patches may be used. The parasitic patches  214 - 217  are configured (e.g., sized and shaped) and disposed to parasitically receive signals from the radiating patch  212  and to re-radiate energy in the multiple frequency bands. 
     In an example, the patch radiator system  210  is configured to radiate signals of multiple frequency bands and each of the parasitic patches  214 - 217  may have a length  230  (and width) of a length to facilitate radiation at a higher frequency band, e.g., above 50 GHz such as in a 60 GHz band. For example, the length  230  may be about a half of a wavelength (e.g., between 0.4 and 0.6 wavelengths) of a higher frequency signal fed to and radiated by the radiating patch  212 . Each of the parasitic patches  214 - 217  may be separated from adjacent ones of the parasitic patches  214 - 217  by a gap length  232  such that an array length  234  of adjacent ones of the parasitic patches  214 - 217  and the gap length  232  is of a length that facilitates radiation of signals of a lower frequency, e.g., in the 28 GHz band. For example, the array length  234  may be about a half of a wavelength (e.g., between 0.4 and 0.6 wavelengths) of a lower frequency signal fed to and radiated by the radiating patch  212 . The gap length  232  is sized such that adjacent ones of the parasitic patches  214 - 217  can operate in combination to radiate lower-frequency signals while permitting individual ones of the parasitic patches to radiate higher-frequency signals. As shown, the parasitic patches are disposed overlapping the patch radiator  212 , centered over the patch radiator  212 , and symmetrically disposed about a center point  236 , which is also the center point of the patch radiator  212 . The radiating patch  212  may similarly be configured to radiate in the higher and lower frequency bands, for example being sized as a multiple or fraction of a plurality of wavelengths of signals for transmission or reception. 
     In another example, the parasitic patches are configured to re-radiate energy over a wide frequency band. For example, the parasitic patches  214 - 217  may be sized to re-radiate energy over a frequency band from 28 GHz to 39 GHz or from 57 GHz to 68 GHz, e.g., with a return loss below a threshold return loss (e.g., −5 dB, or −10 dB) over the band. The size of the parasitic patches  214 - 217  and the gaps  240 ,  242  between the parasitic patches  214 - 217  may be adjusted to affect radiation by the parasitic patches  214 - 217 , e.g., return loss as a function of frequency. For example, sizes of the gaps  240 ,  242  may affect the amount of radiation as a function of frequency and the patch radiator system  210  may be configured to effectively radiate signals over a frequency band of 11 GHz or more. In some such embodiments, rather than each individual parasitic patch being configured to radiate a signal at the lower end of the frequency band, two or more of the parasitic patches  214 - 217  may be configured to radiate at all of the frequencies in the band in combination. 
     Referring to  FIG. 11 , with further reference to  FIGS. 1-10 , a method  250  of parasitically receiving and re-radiating signals of different frequency bands includes the stages shown. The method  250  is, however, an example only and not limiting. The method  250  may be altered, e.g., by having stages added, removed, rearranged, combined, performed concurrently, and/or having single stages split into multiple stages. For example, stages  254  and  256  may be performed before, after, or concurrently with stages  258  and  260 , e.g., for use generally or for use in carrier-aggregation techniques. Still other alterations to the method  250  as shown and described are possible. 
     At stage  252 , the method  250  includes radiating a high-band signal in a first frequency band from a radiating patch and a low-band signal in a second frequency band from the radiating patch. For example, the feeds  122 ,  124  may convey respective high-band signals to the radiating patch  118  that radiates the high-band signals from the feeds  122 ,  124  in respective polarizations. As another example, only one of the feeds  122 ,  124  may convey a high-band signal to the radiating patch  118 . As another example, one of the feeds  122 ,  124  may convey a high-band signal to the radiating patch  118  while the other of the feeds  122 ,  124  may concurrently convey a low-band signal to the radiating patch  118 . As another example, the feeds  122 ,  124  may convey low-band signals to the radiating patch  118  that radiates the low-band signals from the feeds  122 ,  124  in respective polarizations. As another example, only one of the feeds  122 ,  124  may convey a low-band signal to the radiating patch  118 . The high-band signals and the low-band signals will typically be provided to the feeds  122 ,  124  at different times, and the feeds  122 ,  124  will each typically be fed only one signal at a time, but different signals may be provided to either of the feeds  122 ,  124  concurrently. The signals conveyed to the radiating patch  118  by the feeds  122 ,  124  may be the same signals or may be different signals (e.g., have different content), even if the signals are of the same frequency band. 
     At stage  254 , the method  250  includes parasitically receiving the high-band signal by a high-band patch. For example, energy of the high-band signal radiated by the radiating patch  118  may be received by the high-band patch  112 . As the high-band patch  112  receives the high-band signal wirelessly, the high-band patch  112  parasitically receives the high-band signal. The high-band patch  112  receives the high-band signal even though the high-band patch  112  receives less than all of the energy of the high-band signal radiated by the radiating patch  118 . 
     At stage  256 , the method  250  includes re-radiating the high-band signal from the high-band patch. For example, the high-band patch  112  radiates energy due to receiving the high-band signal, and thus re-radiates the high-band signal although the high-band patch  112  radiates less than all of the energy of the high-band signal that the high-band patch  112  received from the radiating patch  118 . The high-band patch  112  is configured (e.g., shaped and arranged) to re-radiate high-band energy in each of the high-band polarizations radiated by the radiating patch  118 . As other examples, the high-band patch  152  or the parasitic patch  172  re-radiates high-band signal energy received from the radiating patch  118 . 
     At stage  258 , the method  250  includes parasitically receiving the low-band signal by a combination of the high-band patch and at least one parasitic element. For example, energy of the low-band signal radiated by the radiating patch  118  may be received by the high-band patch  112  and the parasitic elements  114 - 117 , or a combination of the high-band patch  152  and the parasitic element  154 , or a combination of the high-band patch  112 , and the parasitic elements  114 - 117  and  164 - 167 , or a combination of the parasitic patch  172  and the parasitic elements  174 - 177  and  184 - 187 . Other examples of combinations of patch and parasitic element(s) may be used. As the high-band patch  112  and the parasitic elements  114 - 117  receive the low-band signal wirelessly, the high-band patch  112  and the parasitic elements  114 - 117  parasitically receive the low-band signal. The combination of the high-band patch  112  and the parasitic elements  114 - 117  receives the low-band signal even though the combination of the high-band patch  112  and the parasitic elements  114 - 117  receives less than all of the energy of the low-band signal radiated by the radiating patch  118 . 
     At stage  260 , the method  250  includes re-radiating the low-band signal from the combination of the high-band patch and the at least one parasitic element. For example, the high-band patch  112  in combination with the parasitic elements  114 - 117  may radiate energy due to receiving the low-band signal, and thus re-radiates the low-band signal although the combination of the high-band patch  112  and the parasitic elements  114 - 117  radiates less than all of the energy of the low-band signal received from the radiating patch  118 . If only one low-band signal is received from the radiating patch  118 , then less than all of the parasitic elements  114 - 117  (i.e., only the parasitic elements  114 - 117  corresponding to the polarization of the received signal) may re-radiate energy of the low-band signal. The high-band patch  112  in combination with the parasitic elements  114 - 117  is configured (e.g., shaped and arranged) to re-radiate low-band energy in each of the low-band polarizations radiated by the radiating patch  118 . As other examples, the high-band patch  152  in combination with the parasitic element  154 , or the high-band patch  112  in combination with the parasitic elements  114 - 117  and the further parasitic elements  164 - 167 , or the combination of the parasitic patch  172  and the parasitic elements  174 - 177  and  184 - 187  re-radiates each of the low-band signals received from the radiating patch  118 , in corresponding polarizations. 
     Other Considerations 
     The techniques and discussed above are examples, and not exhaustive. Configurations other than those discussed may be used. 
     As used herein, “or” as used in a list of items prefaced by “at least one of” or prefaced by “one or more of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C,” or a list of “one or more of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C), or combinations with more than one feature (e.g., AA, AAB, ABBC, etc.). 
     The systems and devices discussed above are examples. Various configurations may omit, substitute, or add various procedures or components as appropriate. For instance, features described with respect to certain configurations may be combined in various other configurations. Different aspects and elements of the configurations may be combined in a similar manner. Also, technology evolves and, thus, many of the elements are examples and do not limit the scope of the disclosure or claims. 
     Specific details are given in the description to provide a thorough understanding of example configurations (including implementations). However, configurations may be practiced without these specific details. For example, well-known circuits, processes, algorithms, structures, and techniques have been shown without unnecessary detail in order to avoid obscuring the configurations. This description provides example configurations only, and does not limit the scope, applicability, or configurations of the claims. Rather, the preceding description of the configurations provides a description for implementing described techniques. Various changes may be made in the function and arrangement of elements without departing from the spirit or scope of the disclosure. 
     Further, more than one invention may be disclosed.