RELATED APPLICATIONS

[0001] This PCT International application claims priority to, and the benefit of, U.S. Provisional Patent Application No. 63/297,274, entitled “Array of Radiators Asynchronously Directing Power in Plural Directions at Different Radio Frequencies Simultaneously,” filed January 7, 2022; U.S. Provisional Patent Application No. 63/323,738, entitled “Small Formfactor Phased Array for Simultaneous Spatial and Channel Diversity Communications,” filed March 25, 2022; and U.S. Provisional Patent Application No. 63/347,158, entitled “Smartphone Antenna Array,” filed May 31 , 2022, each of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

[0002] Exemplary system and method relating to phased array hardware and operation in communications and/or RADAR systems.

BACKGROUND

[0003] While the sub-6GHz RF spectrum serves the needs of 4G and 4G-LTE mobile wireless networks, 5G networks deployed as of 2020 and future 6G mobile wireless networks under development are likely to have more stringent requirements - much higher peak data rates, much-improved user experience, higher spectrum and energy efficiency, higher mobility, lower latency, higher density of connections and a much-improved ability to move massive peak volumes of data when required, particularly, vis a vis over 5G. The network must operate over, practically speaking, any environment, land, sea, and air, in the millimeter and sub-terahertz range.

[0004] Legacy 5G mobile access infrastructure is likely to continue to be improved, e.g., with new millimeter- wave (mm-wave) spectrum resources that would likely be phased into the improved 5G networks and into future 6G infrastructure, e.g., as exemplified by the FR2 millimeter wave bands, generally referred to as n257, n258, n259, n260, and n261. 5G NR band n257, e.g., has a frequency range from 26.5 - 29.5 GHz with a bandwidth of 3 GHz; n257 covers 26.5 to 29.5 GHz for Japan, North America, and South Korea; n258 covers 24.25 to 27.5 GHz for Europe and China; n261 covers narrower 27.5 to 28.35 GHz for operation alongside n260 (39 GHz) in the U.S.

[0005] Current base station phased arrays employed in such 5G and 6G technology typically employ only one communication band with low aspect ratio radiators. State-of-the-art implementation of side-by-side phased arrays capable of multichannel communication would implement a large area patch antenna array.

[0006] There is a benefit to improving antenna system configurations that could meet the anticipated requirements of 5G and 6G communication technology.

SUMMARY

[0007] An exemplary system and method are disclosed for an interpenetrating set of phased array monopoles configured to asynchronously radiate radio frequency signals simultaneously on a plurality of radio frequency bandwidths in a plurality of spatial directions. The monopole configuration (in being substantially larger than its in-plane dimension), as implemented in an interpenetrating set of phased arrays, increases the density of the phased array (thus reducing its size) while allowing for phase array operation to be employed. The interpenetrating set of phased arrays includes a plurality of radio frequency filters, a plurality of radio frequency radiators, and a plurality of phase shifting circuitries of mechanisms to provide precise spatial beam coverage (e.g., that can concentrate beam energy in specific directions (i.e., wanted main lobe) while minimizing nearest neighbor interference and minimizing the unwanted formation of sidelobes that waste energy and reduce efficiency). It can also provide simultaneous and asynchronous channel and spatial diversity (e.g., in or from simultaneous plural directions, and devoid of mutual interference) as well as efficient power usage and minimal complexity (e.g., by sharing RF chain resources whenever possible and taking full advantage of 2.5D integration increasingly availed as foundry technology offerings), in a substantially small area (and much smaller than conventional phase array equivalents).

[0008] The interpenetrating set of phased arrays may be implemented in unit cells that individually include a sub-array lattice of radio frequency radiators to provide individual phase array operation, across the multiple unit cells, for sets of monopoles in the sub-array lattice. N radio frequency radiators within the sub-array lattice can provide N number of independent phase array operations for a given frequency band and direction. To this end, the number of unit cells can define the phase array cells, and the number of monopoles in the sub-array lattice among the unit cells can define the number of individual phase arrays. The interpenetrating set of phased arrays can be implemented in a small form-factor and readily scaled by adding panels of independent beamformers side by side in a unit cell.

[0009] The monopole can form a cylindrical rod or have a substantially cylindrical rod shape, as a rod monopole or rod monopole radiator, or have other cross-sectional shapes. The radius of each monopole can be substantially less than % of the radio frequency wavelength of use. The in-plane separation among rod monopole radiators can be substantially less than % of the radio frequency wavelength of use. An example radio frequency radiator structure employing the interpenetrating set of phased arrays may be implemented in a small form-factor, multi-frequency beamformer with a quarter wave monopole formed above a ground-plane reflector. The monopoles may be arranged in a uniform (e.g., equal spacing in the X or Y direction) or non-uniform manner (e.g., non-equal spacing in the X or Y direction) is the subarray lattice. The unit cells may be arranged in a uniform or non-uniform manner among each other.

[0010] In an aspect, an apparatus (e.g., RF antenna module or radar antenna) is disclosed having an interpenetrating set of phased arrays configured to asynchronously radiate radio frequency signals simultaneously on a plurality of radio frequency bandwidths in a plurality of spatial directions, the apparatus comprising a first set of radiators, including a first radiator, wherein each radiator of the first set of radiators has a uniform first defined spacing to a next radiator of the first set of radiators, wherein the first set of radiators is configured to radiate during operation at a first radio frequency bandwidth in a first spatial direction; and a second set of radiators, including a second radiator, wherein each radiator of the second set of radiators has the uniform first defined spacing to a next radiator of the second set of radiators, wherein the second set of radiators is configured to signal during operation at a second radio frequency bandwidth in a second spatial direction, wherein the first radiator has a second defined spacing to the second radiator, wherein the second defined spacing is less than the first defined spacing.

[0011] In some embodiments, the first set of radiators and the second set of radiators are located in plural unit cells (e.g., plural beamforming unit cells) (e.g., negligibly distance apart from each other), including a first unit cell comprising the first radiator and the second radiator, wherein each unit cell of the plural unit cells is configured to concurrently generate, via the first set of radiators and the second set of radiators, signals at distinct radio frequency bandwidths at the plural spatial directions.

[0012] In some embodiments, each of the plural unit cells includes a sub-array lattice of radio frequency radiators and has one electrically conducting current return plane.

[0013] In some embodiments, the first radiator has a vertical dimension and in-plane dimensions, wherein the vertical dimension is substantially larger than the in-plane dimensions. [0014] In some embodiments, the first radiator has a cylindrical rod shape as a monopole radiator.

[0015] In some embodiments, each radiator of the interpenetrating array of elongated radio frequency (RF) radiators has a cylindrical rod shape as a rod monopole (e.g., comprising a good conductor).

[0016] In some embodiments, the monopole radiator has a radius substantially less than % of the radio frequency wavelength of use.

[0017] In some embodiments, the single sub-array lattice of radio frequency radiators has a separation to the electrically conducting ground plane of at least l/30th of % of the radio frequency wavelength of use.

[0018] In some embodiments, the first defined spacing among the first set of radiators provides an in-plane separation of less than % of the radio frequency wavelength of use.

[0019] In some embodiments, the monopole radiator extends from the closest approach to the electrically conducting ground plane is substantially % of the radio frequency of use.

[0020] In some embodiments, the sub-array lattice of radio frequency radiators comprises Nx monopole radiators disposed along a direction x, and N _y monopole radiators disposed along a direction y.

[0021] In some embodiments, the Nx monopole radiators are disposed along the direction x orthogonal to the direction y along the same plane, wherein distances among each of the Nx monopole radiators are the same.

[0022] In some embodiments, the Nx monopole radiators are disposed along the direction x orthogonal to the direction y along the same plane, wherein distances among at least two of the Nx monopole radiators are different. [0023] In some embodiments, the Nx monopole radiators are disposed along the direction x orthogonal to the direction y along the same plane, wherein distances among each of the N _y monopole radiators are the same.

[0024] In some embodiments, the Nx monopole radiators are disposed along the direction x orthogonal to the direction y along the same plane, wherein distances among at least two of the Nx monopole radiators are not the same as distances among at least two of the N _y monopole radiators.

[0025] In some embodiments, the distances among each of the Nx monopole radiators are more than % of the wavelength of the radio frequency of use.

[0026] In some embodiments, the distances among each of the Nx monopole radiators are less than ’/ ₂ of the wavelength of the radio frequency of use.

[0027] In some embodiments, the distances among each of the Nx monopole radiators are equal to the coherence distance to an adjacent monopole radiator.

[0028] In some embodiments, each of the plural unit cells has in-plane dimensions substantially equivalent to the coherence length at the radio frequency of use.

[0029] In some embodiments, the plural unit cells have in-plane dimensions equivalent (e.g., substantially equivalent, e.g., less than 5% or 1%) to the coherence length at the radio frequency of use.

[0030] In some embodiments, the plural unit cells in-plane dimensions form a uniform linear array.

[0031] In some embodiments, the plural unit cells in-plane dimensions form a non-uniform array.

[0032] In some embodiments, the apparatus further includes a peripheral conductive structure that circumvallates at least two adjacent sides of at least one of the plural unit cells. [0033] In some embodiments, the apparatus further includes a peripheral conductive structure that circumvallates all sides of at least one of the plural unit cells.

[0034] In some embodiments, the peripheral conductive structure has a height that is the same as that of the first radiator.

[0035] In some embodiments, the apparatus further includes an encapsulation layer that encapsulates the first set of radiators and the second set of radiators. [0036] In some embodiments, the apparatus further includes an encapsulation layer that encapsulates the sub-array lattice of radio frequency radiators of the plural unit cells.

[0037] In some embodiments, the encapsulation layer has a relative electrical permittivity Sr > 1.

[0038] In some embodiments, the apparatus further includes a plurality of radio frequency filters; the plurality of filters include one or more bandpass filters (e.g., having a substantially narrow band of radio frequencies).

[0039] In some embodiments, a first portion of the plural radio frequency filters are placed at an input of each of the first set of radiators, and a second portion of the plural radio frequency filters are placed at an output of each of the first set of radiators.

[0040] In another aspect, an apparatus is disclosed comprising a set of N unit cells of M monopole radiators, wherein the M monopole radiators of a unit cell form M inter-penetrating arrays with corresponding M monopole radiators of adjust unit cells, wherein each unit cell of the set of N unit cells is configured to independently generate, via the first set of radiators and the second set of radiators, signals at distinct radio frequency bandwidths at a spatial direction. [0041] In some embodiments, the M monopole radiators each comprise % wavelength rod, the wavelength corresponding to a frequency of operation of the respective monopole radiator. [0042] In some embodiments, each M monopole radiator of a given unit cell has a same corresponding location to an M monopole radiator of the cell in adjacent unit cells.

[0043] In some embodiments, each M inter-penetrating array comprises an input bandpass filter (e.g., appropriate bandpass filter at its input) and an output bandpass filter (e.g., appropriate bandpass filter at its output) (e.g., the filters having a range for an operating frequency, e.g., n257, n258, n259, n260, and n261, etc., that is within between 1 GHz and 60 GHz).

[0044] In some embodiments, each M inter-penetrating array comprises a phase shifting element or phase shifting means (e.g., where each M inter-penetrating array forms an independent phased array of monopole radiators that can transmit and receive signals on an assigned radio frequency channels designated by the radio frequency passband of said filters and direct array gain in designated directions simultaneously for both transmit and receive radio frequency signals).

[0045] In some embodiments, the set of N unit cells of M monopole radiators are configured to simultaneously transceive (transmit and/or receive) on a set of designated radio frequency channels (e.g., having an allocated center frequency and allocated bandwidth) for a set of designated directions, wherein each M inter-penetrating array is assigned at least one channel of the set of designated radio frequency channels.

[0046] In some embodiments, the set of N unit cells of M monopole radiators are configured to simultaneously and asynchronously transceive (transmit and/or receive) on a set of designated radio frequency channels (e.g., having an allocated center frequency and allocated bandwidth) for a set of designated directions, wherein each M inter-penetrating array is assigned at least one channel of the set of designated radio frequency channels.

[0047] In some embodiments, an inter-penetrating array of the M inter-penetrating array can simultaneously and asynchronously transceive (transmit and/or receive) on the set of designated radio frequency channels (e.g., having an allocated center frequency and allocated bandwidth) for a given direction by applying an x-phase shift, a y-phase shift, or a combination thereof, between adjacent monopoles associated with (i) an x-row of monopoles or (ii) a y-row or monopoles, of the interpenetrating array.

[0048] In some embodiments, the apparatus further includes a beamforming controller, the beamforming controller being configured to determine an x-phase shift, a y-phase shift, or a combination thereof, between adjacent monopoles associated with (i) an x-row of monopoles or (ii) a y-row or monopoles, of the interpenetrating array, to direct transmission or reception of a signal for a direction (e.g., wherein the x-phase shift or y-phase shift determines the azimuthal and elevation directions of RF gain of the array).

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The skilled person in the art will understand that the drawings described below are for illustration purposes only.

[0050] Fig. 1, 2A, and 2B are each diagram showing an example antenna module, e.g., RF antenna module or radar antenna, having interpenetrating sets of phased arrays configured to simultaneously radiate radio frequency signals, asynchronous or otherwise, on a plurality of radio frequency bandwidths in a plurality of spatial directions in accordance with an illustrative embodiment.

[0051] Figs. 3A, 3B, and 3C are each diagrams showing example dimensions for the interpenetrating antenna module of Fig. 1 in accordance with an illustrative embodiment. [0052] Figs. 4A and 4B are each diagrams showing an example operation of the interpenetrating set of phased arrays of an antenna module in accordance with an illustrative embodiment.

[0053] Figs. 4C and 4D are each diagrams showing an interpenetrating set of phased array monopoles configured as a 2-D Phased MIMO RADAR in accordance with an illustrative embodiment.

[0054] Figs. 5 A and 5B each is a diagram showing an example component assembly of the antenna module of Figs. 1-4 in accordance with an illustrative embodiment.

[0055] Figs. 5C and 5D are each a diagram showing an example signal processing channel for a set of interpenetrating arrays in accordance with an illustrative embodiment.

[0056] Fig. 5E shows an example front-end module that may couple to the signal processing channel of Figs. 5C or 5D in accordance with an illustrative embodiment.

[0057] Figs. 6A - 6G shows an Ansys High-Frequency Simulation Software (HFSS) model for an interpenetrating array and corresponding simulation results.

[0058] Figs. 7A - 7C shows an Ansys High-Frequency Simulation Software (HFSS) model for a patch array antenna and corresponding simulation results.

DETAILED DESCRIPTION

[0059] To facilitate an understanding of the principles and features of various embodiments of the present invention, they are explained hereinafter with reference to their implementation in illustrative embodiments of structures. The materials and components described hereinafter as making up the various elements of the present invention are intended to be illustrative and not restrictive. Many suitable materials and components that would perform the same or a similar function as the materials and components described herein are intended to be embraced within the scope of the invention. Further, such other materials not described herein can include, but are not limited to, materials that are developed after the time of the development of the invention, for example.

[0060] Some references, which may include various patents, patent applications, and publications, are cited in a reference list and discussed in the disclosure provided herein. The citation and/or discussion of such references is provided merely to clarify the description of the disclosed technology and is not an admission that any such reference is “prior art” to any aspects of the disclosed technology described herein. In terms of notation, “[n]” corresponds to the nth reference in the reference list. For example, Ref. [1] refers to the 1st reference in the list. All references cited and discussed in this specification are incorporated herein by reference in their entirety and to the same extent as if each reference was individually incorporated by reference. [0061] Example System #1

[0062] Fig. 1 is a diagram showing an example antenna module 100 (shown as 100a), e.g., RF antenna module or radar antenna, having interpenetrating sets of phased arrays configured to simultaneously radiate radio frequency signals, asynchronous or otherwise, on a plurality of radio frequency bandwidths in a plurality of spatial directions in accordance with an illustrative embodiment. In the example shown in Fig. 1, the interpenetrating sets of phased arrays of apparatus 100a are implemented across a set of unit cells 102, each having a sub-array lattice populated by radiators 106. Each radiator 106 of the sub-array lattice of a given unit cell 102 can operate collectively, with corresponding radiators of other sub-array lattices in adjacent unit cells as a phased array. To this end, N number of phase arrays or channels can be implemented across the unit cells using the N radiative element (i.e., a monopole) of each unit cell.

[0063] In diagram 101a, the antenna module 100a has 64 unit cells (102) configured in an 8 x 8 unit-cell configuration. In diagram 101b, details of 4 unit cells 102 (shown as 102a, 102b, 102c, 102d) of the 64 unit cells of diagram 101a are shown in which each unit cell 102a, 102b, 102c, 102d includes a number of monopole radiators 106. Each monopole radiator 106 of a unit cell forms a phased array 104 (shown as 104a, 104b, 104c, 104d, 104e, 104f, 104g, 104h, 104i), as it operates with other corresponding monopole radiators 106 in adjacent and other unit cells 102.

[0064] In Fig. 1, as shown in diagram 101b, each unit cell 102a, 102b, 102c, 102d includes a sub-array lattice of radiators 106 (shown as 106a, 106b, 106c, 106d, 106e, 106f, 106g, 106h, 106i) in which each radiator 106a-106i forms a part of a phased array 104a, 104b, 104c, 104d, 104e, 104f, 104g, 104h, 104i (see Fig. 3). Though not shown with labels in diagram 101b, the same repeating pattern of radiator 106a, 106b, 106c, 106d, 106e, 106f, 106g, 106h, 106i for the phase arrays 104a, 104b, 104c, 104d, 104e, 104f, 104g, 104h, 104i are also present in unit cells 102a, 102b and, e.g., all the unit cells of the antenna module.

[0065] Diagram 101c is a diagram showing a trimetric perspective of an example configuration of a unit cell 102c comprising a sub-array lattice populated by radiators 106 (e.g., 106a-106i) configured as a rod monopole. In the example shown in Fig. 1, each radiator 106 is uniformly spaced in the x and y directions by an x-distance (Ax) and a y-distance (Ay) in which Ax =Ay. In Fig. 2A, each radiator 106, in the example, is uniformly spaced in the x and y directions by an x-distance (Ax) and a y-distance (Ay) in which Ax Ay.

[0066] Referring to Fig. 1, the antenna module 100a includes an insulator substrate 120 having a pre-defined thickness that supports the radiators 106. In the example shown in Fig. 1, the substrate 120 is formed over or attached to an electrical return plane 110 (e.g., a metal layer). The electrical return plane 110 may be configured as a solid plane, or it may be patterned.

[0067] In the example shown in Fig. 1, the antenna module 100a includes a conductive shield wall 130, e.g., formed of a conductive material, e.g., a metal structure, that circumvallate the rod monopole 106 of each unit cell 102. The circumvallating conductive shield wall 130 in forming a perimeter around the close-packed monopoles of a unit cell can balance the effect of the monopoles. In some embodiments, the shield wall 130 may extend along only a portion of the periphery (not shown).

[0068] The monopole 106 may be fabricated as a single unitary structure in some embodiments. In other embodiments, the monopole 106 may be fabricated in layers to form a structure or the single unitary structure. The substrate 120 may encapsulate a portion or the entirety of the monopole 106. The dimensions of the monopole 106 for each of the set of interpenetrating arrays may be configured for a particular frequency band, e.g., n257, n258, n259, n260, and n261, sub-6GHz RF spectrum, mid-band within the 7-24 GHz range, subterahertz (sub-THz) band in the 92-300 GHz range, among others described herein.

[0069] In the example of Fig. 1, as shown in diagram 101b, the antenna module 100a includes an encapsulation 130 comprising an insulating material, e.g., having relative dielectric permittivity s _r > 1, to enhance directivity by the antenna module. Fig. 2A shows an example antenna module 100 (shown as 100b) without the encapsulation 130. Fig. 2B shows the unit cell of another example antenna module 100 (shown as 100c) that includes the encapsulation 130, though the encapsulation 130 is formed over each individual unit cell 102.

[0070] Figs. 3A, 3B, and 3C are each diagrams showing example dimensions for the interpenetrating antenna module 100c of Fig. 1. Identification of each monopole by its location in the sub-array lattice and unit cell is displayed and annotated in the inset 302. The doubleheaded arrows indicate the distance between monopoles at each corresponding locations of a given sub-array lattice in relation to adjacent unit cells. In Fig. 3A, the distance between individual element 106 of a phased array 104 as constructed by the sub-array lattice of the unit cell is uniform in the x-direction and the y-direction. In Fig. 3B, the distance between individual element 106 of a phased array 104 are non-uniform in the x-direction and the y-direction. The distance may correspond substantially to the coherence length. Coherence length is the propagation distance over which a coherent wave maintains a specified degree of coherence. Wave interference is strong when the paths taken by all of the interfering waves differ by less than the coherence length. A wave with a longer coherence length is closer to a perfect sinusoidal wave. Beamforming arrays of Huygens-Fresnel radio frequency radiators are obliged to obey the physical principles of coherence distance between radiating structures and electrical resonance frequencies inherent in the dimensions of the radiator; the first scaling in opposition to, while the latter scales in sympathy with radio frequency.

[0071] As further shown by the labels in Figs. 3 A, 3B, and 3C, each monopole 106 is identified by its location in the sub-array lattice/unit cell 102 as displayed and annotated in the inset 302. The insert 302 provides an example unit cell monopole taxonomy that defines the order and naming protocol for a given unit cell. In insert 302, the sequence is defined as (c, x, y) in which “c” refers to the unit cell, “x” refers to the x-coordinate of a monopole in unit cell “c”, and “y” refers to the y-coordinate of a monopole in the same unit cell “c”. The twin-head arrows indicate the coherent distance between monopoles in adjacent unit cells. Each arrow is substantially % of the radio frequency wavelength of use.

[0072] The arrays of all monopoles located at the same corresponding sub-array lattice points among the adjacent unit cells form an interpenetrating array. To this end, the 2 x 2 array of unit cells of Figs. 3 A and 3B show 9 independent interpenetrating arrays arranged in a 3 x 3 configuration. Other configurations may be employed, e.g., 1 * 2, 2 * 1, 2 * 2, 3 * 1, 3 x 2, 3 * 3, 1 x 3, 2 x 3, 1 x 4, 2 x 4, 3 x 4, 4 x 4, 4 x 3, 4 x 2, 4 x 1, 1 x 5, 2 x 5, 3 x 5, 4 x 5, 5 x 5, 5 x

4, 5 x 3, 5 x 2, 5 x 1, 1 x 6, 2 x 6, 3 x 6, 4 x 6, 5 x 6, 6 x 6, 6 x 5, 6 x 4, 6 x 3, 6 x 2, 6 x 1, 1 x

7, 2 x 7, 3 x 7, 4 x 7, 5 x 7, 6 x 7, 7 x 7, 7 x 6, 7 x 5, 7 x 4, 7 x 3, 7 x 2, 7 x 1, 1 x 8, 2 x 8, 3 x

8, 4 x 8, 5 x 8, 6 x 8, 7 x 8, 8 x 8, 8 x 7, 8 x 6, 8 x 5, 8 x 4, 8 x 3, 8 x 2, 8 x 1, among others, e.g., 9 x 9, 10 x 10, 11 x H _? 12 x 12, 13 x 13, 14 x 14, 15 x 15, and similar variations thereof. In other configurations, the phase arrays of the antenna module 100 may be arranged to form a square-shaped module, a rectangular-shaped module, a circular-shaped module, an oval-shaped module, or other polygonal-shaped modules. In other embodiments, the antenna module may include recesses to be integrated into other structures, e.g., cameras or other components, e.g., in a smart phone device.

[0073] In the example shown in Figs. 1 - 3, the multiple interpenetrating arrays of each unit cell / sub-array lattice 102 each have the same/uniform number of unit elements. The number of interpenetrating arrays for the antenna module 100 may include, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or more, e.g., one per band of operation, e.g., n257, n258, n259, n260, and n261. In other embodiments, the number of interpenetrating arrays may be different, e.g., a “partly interpenetrating arrays” of monopole radiators in which some member monopoles appear in at least some sub-array lattice belonging to every unit cell. The term “interleaved arrays” of radiators may be interchangeably with the term “partly interpenetrating arrays.” For example, each interpenetrating array can independently have a different number of antenna modules among the unit cell / sub-array lattice 102 - that is, it can be fully interpenetrating or partially interpenetrating. For example, fully interpenetrating array #1 may have 16 phased-array elements in an antenna module having 16 unit cells configured in a 4 x 4 configuration, while partially interpenetrating array #2 includes 14 phased-array elements in the same 16 unit cells, while partially interpenetrating array #3 includes 4 phased-array elements, and etc. In some embodiments, interpenetrating arrays dispersed among the unit cell / sub-array lattice 102 of an antenna module 100 may be co-located in the antenna module with a single monopole radiator (non-phase array).

[0074] Example Operation

[0075] Fig. 4A is a diagram showing an example operation of the interpenetrating set of phased arrays of an antenna module 100a (shown as 100a’) in accordance with an illustrative embodiment. In the example shown in Fig. 4A, the antenna module 100a’ includes an array of 4 unit-cells 102a, 102b, 102c, 102d, each having a sub-array lattice of 3 x 3 equally spaced rod monopoles 106. Each monopole 106, located at a point in the sub-array lattice of a unit cell is offset, in time or phase, relative to a monopole located at a corresponding point in the sub-array lattice of an adjacent unit cell. In the example shown in Fig. 4A, the relative phase shifts are represented by Ox (402) and <p> (404) corresponding to phase shifts in the x and y directions. [0076] In the example shown in Fig. 4A, the antenna module 100a’ is configured as a beamforming array that includes 4 unit cells 102a-102d, with or without conducting shield walls. Each unit cell 102, as shown, includes a 3 x 3 sub-array lattice of 9 monopoles 106. Monopoles 106 at each corresponding sub-array lattice coordinate, taken together, form lattices that interpenetrate all other lattices similarly constituted. Thus, in Fig. 4A, there are 9 interpenetrating arrays, or lattices, each comprising a 2 x 2 array of monopoles. Each of the 9 interpenetrating arrays in Fig. 4A is a beamforming array that each includes a signal channel 406 (, e.g., “Signal Bands” 406a, 406b, 406c, 406d, 406e, 406f, 406g, 406h, 406i) that couples to a bandpass filter 408 (e.g., narrow bandpass filters (“NBPF”) (408a, 408b, 408c, 408d, 408e, 408f, 408g, 408h, 408i). In Fig. 4A, only three channels (406a-406c) and filters (408a-408c) are depicted to avoid drawing congestion.

[0077] In some embodiments, the signals provided to the respective interpenetrating array is a narrow band signal having frequency “fl” to “f9” (in this example of 9 interpenetrating arrays). In such embodiments, NBPF may be optional.

[0078] The antenna module 100a’ may include beamforming or steering circuitries or is coupled to such circuitries to beamform and/or steer coherent radio frequency emissions, e.g., by adjusting a relative phase shift between corresponding monopole radiators located in corresponding sub-arrays located on adjacent unit cells. For example, if a relative phase shift, Ox (402) or <py (404), is applied between (unit-cell- wise) adjacent monopoles in all “x” rows or “y” rows, respectively, in the entire array of unit cells, then a coherent radio frequency emission can be made to occur at a desired angle of elevation above the ground plane and at a desired azimuth angle in said plane. In Fig. 4A, the monopoles may be configured to have % wavelength monopoles formed over or attached to the ground plane 120. The cross-thatching patterns shown in the monopole are only for illustrative purposes to designate a different frequency band of operation.

[0079] Beamforming and steering circuitries may be implemented, e.g., in a front-end module that interfaces with the antenna module 100a’. The front-end module may include additional circuitries such as a power amplifier, low noise amplifier, T/R switch, directional coupler, power management circuitries, etc. In some embodiments, the beamforming and steering circuitries may be integrated with the antenna module 100a’ in an antenna- in-package (AiP) or antenna-on-package (AoP) device.

[0080] Fig. 4B is a diagram showing the operation of another example configuration of an antenna module 100 (shown as lOOe) comprising four interpenetrating arrays included in 12 unit cells 102 configured in a 3 x 4 array configuration. The unit cells 102 are configured in a 1 x 4 sub-array lattice of substantially similar or same rod monopoles represented by geometrical shapes and identifying coordinate labels. Indeed, the grouping of all circles, triangles, diamonds, or squares each defines an interpenetrating array that is configured for operation at a particular frequency band. The separation/distance between interpenetrating arrays in adjacent unit cells may be established as the coherence distance between the rod monopole of that interpenetrating array. Each interpenetrating array may be spectrally isolated from all other interpenetrating arrays and can independently steer radiated power in a different direction. In Fig. 4B, the relative phase shift d 1 -d4 (402a, 402b, 402c, 402d) between monopoles may be controlled along the x- rows “1” through “4” associated with interpenetrating arrays “1” through “4” while phase shift (pl -<p4 (404a, 404b, 404c, 404d) between monopoles may be controlled belong the y-rows “1” through “4” associated with interpenetrating arrays “1” through “4.” In other embodiments, the phase shift or relative phase shift for each monopole element of a given interpenetrating array may be independently or individually controlled. For simplicity, the unit cells in Fig. 4B are shown as one quadrant of the antenna module. In some embodiments, the signal feed line is provided to the center, and a positive relative phase shift is applied in one quadrant of the antenna module, while a negative relative phase shift is applied in the opposite quadrant.

[0081] Corresponding monopoles 106 in adjacent unit cells may be controlled, e.g., via their relative phase shifts, to direct radiated radio frequency energy in a desired direction. In Fig. 4B, the application of relative phase shift cp _n between corresponding monopoles (n) in adjacent unit cells may control the elevation of radiated energy along the y-direction, while phase shifts S _m between corresponding monopoles (m) in adjacent unit cells may control the azimuth of radiated energy along the x-direction.

[0082] The radio frequency phased array may be used, e.g., in smartphones, to direct electromagnetic energy generated during transmission away from the user’s upper head area. [0083] 2-D Phased MIMO RADAR

[0084] Fig. 4C shows an interpenetrating set of phased array monopoles configured as a 2-D Phased MIMO RADAR. Interpenetrating arrays used in communications are all substantially the same, but each interpenetrating array functions autonomously both in channel frequency assignment and in programmed directivity gain. When applied to phased MIMO radar, some interpenetrating arrays may be assigned to the task of target illumination using random and rotating frequency as well as a random and rotating set of orthogonal waveforms for illumination. These dynamic array selections must be coordinated.

[0085] Phased-MIMO RADAR can partition the transmitting array into a number of subarrays that are allowed to overlap. Then, each subarray is configured to coherently transmit a waveform that is orthogonal to the waveforms transmitted by other subarrays. Coherent processing gain can be achieved by designing a weight vector for each subarray to form a beam towards a certain direction in space. Moreover, the subarrays may be combined to jointly form a MIMO radar that can provide higher target resolution. For example, the interpenetrating set of phased arrays configured with multiple inputs multiple outputs (MIMO) radar, along with underlying integrated circuits, digital coding, and packaging technology, may be employed to resolve and track for specific targets embedded in a swarm.

[0086] The example 2D phased MIMO RADAR implemented with the interpenetrating set of phased array monopoles can provide a large number of high aspect ratio radiators in a small footprint compatible with 2.5 D vertical packaging integration, e.g., for airborne or satellite deployment. In some embodiments, the system may be configured with an optimized selection of orthogonal waveforms that may be used to enhance the detection and tracking of a single target among a swarm of targets. The system may have reduced the complexity of the air interface and a high number of easily switchable phased arrays, each operating different waveforms and digitally coded channels. The MIMO feature may extend virtual receive channels, e.g., to improve angular resolution and interference immunity associated with digitally coded channels. These extended capabilities may provide improved range resolution, better signal-to-noise ratio, and faster updates with short system cycles.

[0087] Phased-MIMO radar with co-located radiators can retain the benefits of (A) colocated MIMO radar and (B) phased arrays. In one embodiment for a co-located (monostatic) MIMO radar, the transmitting radiators can be configured to be close to one another so that the observed target radar cross sections by each transmitting array element are identical. In a phased array, each radiator is configured to only transmit a copy of a transmission waveform that has been generated by a central waveform generator, although there may be a phase difference in the radiated signal among individual radiators in the phased array. In a MIMO radar system, each radiator has its own arbitrary waveform generator, and subsequently, each radiator uses an individual waveform. Another benefit, among others, of the phased-array, is the coherent processing gain of the transmitter array. By partitioning the transmitting array into a number of overlapping subarrays, each subarray can be used to coherently transmit a waveform that is orthogonal to the waveforms transmitted by other subarrays. Coherent processing gain can be achieved by designing a weight vector for each subarray to form a beam towards a certain direction in space.

[0088] When the subarrays are combined to jointly form a phased MIMO radar, the results are expected to be substantially higher target resolution. Additional descriptions and examples of a phased-array MIMO RADAR may be found in [23] and [24],

[0089] In Fig. 4C, the phase delay relation between selected adjacent monopole radiators for 4 unit cells, UC1 - UC4, arranged in a 2 x 2 array, is shown. In the example of Fig. 4C, each unit cell includes a 3 x 3 sub-array of monopole radiators numbered from “1” through “9.” The phase shift difference between the adjacent radiators in the X direction is indicated by <p, while the phase shift difference between adjacent radiators in the Y direction is indicated by v . The number prefix denotes association with specific numbered monopoles belonging to each sub-array. Arrays formed by like numbered radiators belonging to each unit cell form indistinct interpenetrating arrays in accordance with the stated definition for interpenetrating arrays. Each interpenetrating array becomes distinct upon function assignments such as channel frequency and array gain direction.

[0090] During operation, signal “1,” filtered by bandpass filter BPF “1,” may be introduced at a first monopole “1,” for example, and sequentially disseminated to all other instances of monopole “1” within interpenetrating array “1.” The phase delay between adjacent instances of monopole “1” in the X direction is represented by lip, while the phase delay between adjacent instances of monopole “1” in the Y direction is represented by h . Similarly, the phase delay between adjacent instances of monopole “5” in the X direction is represented by 5(p, while the phase delay between adjacent instances of monopole “5” in the Y direction is represented by 5\p, and the phase delay between adjacent instances of monopole “9” in the X direction is represented by 9<p, while the phase delay between adjacent instances of monopole “9” in the Y direction is represented by 9\p. Similar operations may be performed for monopoles “2,” “3,” “4,” “5,” “6,” “7,” and “8”. [0091] The combined operation provided for 9 frequency band in 9 different beamformed directions across the 2 x 2 unit cells. In Fig. 4C, the phase shifters <p and \|/ are shown only for monopoles “1,” “5,” and “9” for readability.

[0092] Fig. 4D shows interpenetrating array “7” configured, e.g., to illuminate a target, while at least one of the remaining sets of the interpenetrating arrays “1” through “6” and “8” and “9” being employed, e.g., to track the reflected signals from a swarm of targets and simultaneously track a specific target. The interpenetrating array can be connected to RF chain and DSP parallel computing to provide parallel tracking with an ultra-compact dynamically switched set of arrays that can switch operations among arrays with frequency and waveform previously assigned to each.

[0093] Example Component Assembly

[0094] Figs. 5A and 5B each is a diagram showing example component assembly 500 (shown as 500a and 500b) of the antenna module 100 of Figs. 1-4 in accordance with an illustrative embodiment. In the examples shown in each of Figs. 5A and 5B, the foundry processes employed 2.5-D integration based on an interposer and plastic pin grid array process for fabricating arrays of % wavelength monopoles.

[0095] In Fig. 5A, an array of % wave rod monopoles is shown mounted above the monopole ground (shown as the current return plane or “ground plane”). In Fig. 5B, the array of monopoles is shown encapsulated in the substrate 120. Uplink and downlink signals to the monopoles or array thereof may be directed, in part, by wiring redistribution layers RDL1 (502) and RDL2 (504), e.g., through a “Passive Interposer.” Phase shifting control of the monopoles or arrays may occur in the ’’Phase Shift Layer” (506), which may comprise, in part, 30GHz 5-bit Digital phase shifters based on monolithic micro wave integrated circuits (e.g., manufactured by Qorvo semiconductor, Greensboro, North Carolina, USA).

[0096] In each of example of Figs. 5A and 5B, the assembly 500a, 500b includes a polymer package substrate 508 (shown as “Polymer Board Substrate” 508) and a top-of-board RDL 510 that can provide mechanical support and electrical connections, e.g., by packaging interconnections 510 (shown as “BGA balls” 510), through board vias 512, C4 bumps 514, an interposer 516, or a combination thereof.

[0097] The assembly 500a, 500b may include an input filter bank 518 (e.g., narrow bandpass filter “NBPF” for each frequency-band channel) to provide filtering for the primary input signal from the “input band” for each interpenetrating array to provide tuning for each outgoing/transmitting channel. Similarly, the assembly 500a, 500b may include filter bank 520 (e.g., narrow bandpass filter “NBPF” for each frequency-band channel) to filter the primary received signal from the “output band” for each channel and to provide tuning to each received channel. Examples of narrow bandpass filters include those that are manufactured Pasternack Enterprises, Inc. (Irvine, California, USA).

[0098] Example Signal Processing and Front-end Module

[0099] Figs. 5C and 5D are each a diagram showing an example signal processing channel for a set of interpenetrating arrays. Fig. 5E shows an example front-end module that may couple to the signal processing channel of Figs. 5C or 5D.

[0100] Example #1. In the example of Fig. 5C, the signal processing channel 550 includes three stages: a first stage that operates in the digital/frequency domain, a second stage that operates in the digital/time domain, and a third stage that operates in the analog/time domain. The channel 550 is configured to prepare a serial digital signal 552 of interest for analog transmission over an air interface “A” 554. The first stage includes a serial-to-parallel converter (S/P) 556 and a Quadrature Amplitude Modulator (QAM) 558. The serial-to-parallel converter (S/P) 556 is configured to convert the serial digital signal to parallel bit streams. The Quadrature Amplitude Modulator (QAM) 558 connects to the parallel outputs of S/P 556 and is configured to convert the parallel steams into in-phase and quadrature components.

[0101] The second stage includes an inverse fast Fourier transform (IFFT) 560, a parallel-to- serial converter (P/S) 564, and a symbol spectrum mask 566 (shown as “Symbol mask insertion” module 566). The inverse fast Fourier transform (IFFT) 560 is configured to convert the digital frequency signals from the Quadrature Amplitude Modulator (QAM) 558 from the frequency domain to the time domain. In this example, the cyclic prefixes (CP) 562 are added as guard bands between successive symbols to overcome intersymbol interference (ISI) at the tradeoff for throughput. Thereafter the signal processing channel 550 includes the parallel-to-serial converter (P/S) 564 to sequence the parallel bit streams into a serial bit stream. The symbol spectrum mask 566 connects to the serial output of the P/S 564. The operation 566 is provided to ensure that transmission can stay within its assigned band to reduce signal spilling into adjacent bands that would otherwise cause inter-band interference. [0102] The third stage includes a digital-to-analog (D/A) converter 568 and a power amplification (PA) and frequency mixing and bandpass filtering (BPF) circuit 570. The digital- to-analog converter 568 is configured to condition the signal for power amplification (PA), and frequency mixing and bandpass filtering (BPF) circuit 570 prepares the resulting analog signal for transmission at the air interface (A) 554. Other signal-processing channel configurations may be employed.

[0103] Example #2. In the example shown in Fig. 5D, the signal processing channels 572 are configured to be used in the transmission of a radio frequency signal coded in orthogonal frequency division multiplexing (OFDM). The channel 572 includes the RF front end. The channel 572 may also be used for a radio frequency chain for a phased array.

[0104] In Fig. 5D, the signal processing channels 572 includes intermediate frequency and baseband subsystem components 574 for 9 interpenetrating arrays “1” through “9,” e.g., implemented across 16 unit cells in a 4 x 4 configuration.

[0105] For each of RF channels “1” through “9,” the intermediate frequency and baseband subsystem components 574 include digital to analog converter (DAC) 578a, analog to digital converter (ADC) 578b, modulator (M) 580, bandpass filters 582a, 582b, variable gain amplifiers 584a, 584b, and a switch (SW) 586. The DAC 578a converts serial digital I/O to an analog signal. The modulator (580) modulates the outgoing signal channel so it can carry data. The bandpass filter 582a limits the modulated signal to a frequency range, which is amplified as the output signals. The switch 586 controls the between incoming and outgoing signals.

[0106] Front-End Module. In the example shown in Fig. 5D, the front-end module 588 includes component 590 for a phased-array millimeter-wave transceiver front-end having channels “1” through “9.” The components 590 includes RF front-end electronic chain for each of the 9 channels, including RF mixers 592a, 592b (each shown as “®”), bandpass filters 582a, 582b, power amplifier (594), low noise amplifier (LNA) (596), and switch 586. The RF mixers 592a, 592b are configured for frequency up / down conversion, respectively, an input signal or output signals. The upconverted signal is filtered and amplified for transmission at the antenna module 100 (shown as lOOf). An incoming signal, once received, is amplified via LNA 596, filtered, and then downconverted via the mixer 592b.

[0107] The front-end module 588 may couple to the intermediate frequency and baseband RF chains, e.g., of Fig. 5C and Fig. 5D. The air interface, e.g., antenna module lOOf, includes a phase shifting network (e.g., 506) integrated into the substrate 120. As noted above, other configurations for phase-shifting circuitries may be employed. The interpenetrating phased array of high aspect ratio radiators 106 is shown arranged in a 2 x 2 array of unit cell in which each unit cell comprises a sub-array of 12 x 12 high-aspect ratio radiators. The phase shifting network 506 includes the <p and v| programmable phase shift integrate circuits.

[0108] Experimental Results and Examples

[0109] A study was conducted to evaluate the exemplary interpenetrating arrays, including simulations to verify the properties of an interpenetrating array. The study evaluated the radiating performance of the interpenetrating array in relation to a baseline patch antenna array radiator.

[0110] Interpenetrating Unit Cell Simulation. Fig. 6A is a diagram showing an Ansys High- Frequency Simulation Software (HFSS) model for an interpenetrating array implemented across an 8 x8 array of unit cells. The 3 x 3 sub-array of monopoles included %X high-aspect ratio monopole radiators. The set of unit cells forms 9 independent interpenetrating arrays configured to operate over an 8 x 8 unit-cell to include 576 total radiators (e.g., 106), e.g., as described in relation to Fig. 1. The 9 interpenetrating arrays, when operating as a phased array, can support 9 independent radio frequency channels and independently direct coherent array gain in 9 desired different directions simultaneously.

[0111] Each unit cell 102 of the HFSS model included a 3 x 3 sub-array lattice of rod monopoles 106 having a 0.1 mm radius and 2.5 mm (’AX at 30 GHz) height above the ground plane 110 disposed below an insulating substrate 120. The substrate 120 was modeled as a Rogers RT/Duroid® 5880 Laminate having dimensions 5 x 5 x 0.1 mm ³ . The monopoles in the sub-array were equally spaced on 1.5 mm centers, which is much less than the ’AX separation required for coherency. The monopole radiators were raised above a ground plane by 0.05 mm. Coaxial feeds were located below the ground plane. Contact with each monopole was made through a hole in the ground plane.

[0112] The simulation introduced a 30 GHz (X = 10 mm) signal (center frequency) to a coaxial coupling 630 to radiating elements (e.g., 106) through probe access holes in the ground plane and wave port excitation.

[0113] The simulation was performed on the HFSS model that included a conducting shield wall 130 of circumvallation that is approximately 1/5X in height as well a HFSS model that did not include the wall 130. The wall 130 was expected to function as a radiation equalizer that could normalize the far-field coherent RF gain for each sub-array, e.g., irrespective of monopole coordinate provenance in a unit cell.

[0114] The separation between radiators belonging to the same interpenetrating array, a model of the near and far field radiation pattern for the array, and the assumption of a received plane wave, can be used to estimate the angle of arrival of a distant RF signal.

[0115] Results. Without the shield wall, the array gain emanating from the interpenetrating phased array having monopoles located at the center of each 3x3 sub-array appear symmetrical. Figs. 6B, 6C, 6D, 6E, 6F, and 6G show results of the simulation of Fig. 6A, specifically, far field emissions, as the coherent array gain of one of 9 interpenetrating arrays formed by (3x3) x (8x8) monopole arrays; 15° Elevation, 15° Azimuth (at the center monopole, Fig. 6B; at the outer monopole, Fig. 6D; at the inner monopole, Fig. 6F); 45° Elevation, 45° Azimuth (at the center monopole, Fig. 6C; at the outer monopole, Fig. 6E; at the inner monopole, Fig. 6G).

[0116] To generate the results shown in Figs. 6B-6G, only one monopole at the center of the unit cell, an inner corner of the unit cell, or an outer corner of the unit cell, was energized. It should be clear to those skilled in the art of phased array design that when every interpenetrating array is spectrally isolated by adequate bandpass filters, there should be no mutual coupling among different interpenetrating phased arrays, but there would be mutual coupling among monopole radiators as members of the same interpenetrating array. Here, there is some benefit to the cylindrical symmetry of the monopole arrays.

[0117] It has been shown in a publication authored by Henault, S. and Y. M. M. Antar, entitled “Unifying the theory of mutual coupling compensation in antenna arrays,” which appears in IEEE Antennas and Propagation Magazine, Vol. 57, pp. 104-122 (2015). [doi:

10.1109/MAP.2015.2414514] that for an array of rod monopoles, the in-plane electric currents Jx and J _y and all magnetic currents would vanish, leaving only the electric currents Jz in the evaluation of the transmitting and receiving coupling matrices. The cancellation of in-plane currents greatly simplifies estimations of the direction of arrival, as is intuitively evident by the cylindrical symmetry of each radiator in the array.

[0118] Comparison with Patch Antenna Array. Fig. 7A is a diagram showing an Ansys HFSS model for an 8 x 8 array of patch antenna array having 64 low-aspect ratio radiators 702 to be used as a comparison to the interpenetrating array model of Fig. 6A. In Fig. 7A, the patch radiator unit cell was configured with a radiator size of 3.4 x 3.4 mm ² . The coaxial probe offset was set as y = 0.75 mm. The substrate 120 was set as Rogers RT/Duroid® 5880, having a laminate size of 5.4 x 5.4 x 0.1 mm ³ . In Fig. 7B, a single high-aspect ratio monopole radiator 106 (shown as 106’) of Fig. 7A is shown in relation to one low-aspect ratio patch radiator 702.

[0119] Results. Figs. 7B and 7C show results of the simulation of Fig. 7A, specifically, far- field emissions, as the coherent array gain, for one of the patch antennas in the antenna arrays; 15° Elevation, 15° Azimuth (Fig. 7B); 45° Elevation, 45° Azimuth (Fig. 7C). The results of Figs. 7B and 7C are generated at matching elevation and azimuthal angles as those in Figs. 6B and 6C for the interpenetrating array.

[0120] While it can be observed that there are differences in power distributions between the monopole and the patch arrays, the main lobes of each design are well-defined. Both types of radiator arrays have energy-wasting sidelobes that can be further reduced by additional design improvements.

[0121] Table 1 shows a comparison of the total directivity gains of the principal emission emanating from an 8x8 phased array of patch radiators and an 8 x 8 array of 3 x 3 sub-arrays comprising 1/4 wave rod monopoles.

Table 1

[0122] Additional experimental results may be found in the publication authored by Daniel Guidotti, Binbin Yang, Muhammad S. Omar, Shang-Jen Su, Yahya M. Alfadhli, Gee-Kung- Chang and Xiaoli Ma, “Small Formfactor Phased Array for Simultaneous Spatial and Channel Diversity Communications,” Journal Progress In Electromagnetics Research Letters, Vol. 104, pp. 37-46 (2022). DOI: 10.2528/PIERL22030504, which is incorporated by reference herein in its entirety.

[0123] Discussion

[0124] The present embodiments generally relate to phased arrays that may find use in communications or RADAR to transmit and receive radio frequency (RF) signals in the form of direct array gain. Thus an array of electrically conducting elements, when used cooperatively, functions in accordance with the Huygens-Fresnel principle. The Huygens-Fresnel principle can be attributed to diverse phenomena and applications, in particular, the far field behavior of radio frequency waves emanating from a Huygens-Fresnel array of sources, under suitable conditions, can be used to direct radio frequency power in desired directions in the fashion of onedimensional light dispersion by a linear light diffraction grating. The direction of propagation of a band of radio waves emanating from a two-dimensional Huygens-Fresnel array of electrically conducting structures can be steered in various spatial directions by judiciously provisioning a set of coordinated delays in the path between adjacent radio frequency electrical currents that may supplied to each radiating structure in the array [14], [15],

[0125] Said electrical currents delays may be referred to as time or phase delays and serve to synchronize electromagnetic fields in the coherent near-field region of radiating Huygens- Fresnel sources in an array of similar sources. This results in a predominately plane RF wave propagating in a predominantly desired direction when sufficiently far from the array. Such a coherent array provides array gain to a transmitter or receiver to cooperatively increase the strength of a radio frequency signal in desired directions

[0126] The state of the art for constructing said arrays for the purpose of 5G base station communications are described in a number of publications and company advert reports/blogs [11] - [13], Generally, but not exclusively, these reports involve radiator arrays comprising substantially low aspect ratio, flat conducting structures, generally referred to as patch arrays, isolated from an electrical current return plane (ground). Common among most beamformer array variations is time multiplexed spatial diversity and single frequency operation.

[0127] In contrast, the exemplary system employ M interpenetrating arrays, each having N x N radiators that can occupy the lateral space of a single array of patch radiators while simultaneously and asynchronously communicating on multiple radio frequency bands (channels) while simultaneously and independently providing M full spatial array gains. The system can asynchronously and simultaneously transmit and receive on plural channels in plural directions with inconsequential interference and with a composite array having a lateral form factor comparable to that of a conventional patch array beamformer that can only operate on one channel and provide arrays gain in one direction at a time.

[0128] Legacy, communication grade, radio frequency beamformers generally comprise easily manufacturable arrays of low aspect ratio patch radiators and are designed to operate optimally in a single frequency band, for example, the n257 mm band in the FR2 millimeter wave spectrum [16],

[0129] Legacy beamformers comprise arrays of radiator structures, substantially in the form of low-profile conducting rectangular patches, principally because of ease of construction and integration. Such arrays of patch radiators are subject to both 1) coherence rule and 2) resonance rule. Elements in a phased array radiate coherently so as to concentrate array energy in specific spatial directions, commonly referred to as array gain. Coherence requires that a sufficiently narrow band of radio frequencies be involved and that radiators (patches) in an array be separated by substantially % the wavelength of the operating RF band, while resonance to the driving RF band requires that the in-plane dimensions of each patch be substantially % wavelength of the operating RF band. These in-plane patch dimensions substantially determine the resonance frequency of the patch, given the relative dielectric permittivity and thickness of the insulator that separates the patch from its reference current return plane (ground plane). Operating RF frequency band, resonance, coherence, and array gain requirements determine the size of a single-phased array formed from patch radiators. The case of multiple RF frequency bands operating simultaneously further requires that the phase arrays be set side by side.

[0130] In [17], the authors reported and demonstrated a scheme that uses specifically designed and interleaved beamformers, all operating in the same radio frequency band, and an algorithm to suppress wireless energy that is radiated in unwanted directions and referred to as “unwanted lobes,” as opposed to wireless energy that is channeled in desired directions and referred to as “desired lobes.” The demonstration promotes addressing multiple users with the same time division multiplexed beamformer platform, which is subdivided into independent subarrays and signaling at the same radio frequency. This platform offers asynchronous spatial diversity but within the same RF signaling band.

[0131] In [18], the authors reported and demonstrated a time-multiplexed interleaved beamforming and energy steering approach. The publication promotes addressing multiple users with the same time division multiplexed beamformer array operating at a single RF band.

[0132] Radiofrequency antenna comprising a single resonant radio frequency radiating element can, by happenstance or by design, operate in two fixed and substantially non-tunable radio frequency bands simultaneously [19] -[20], [0133] In the literature, one can find several structures bearing the label “monopole antenna” [21] - [22],

[0134] Additionally, various types of RAdio Detection And Ranging (RD AR) application use two distinct frequencies in order to enhance global survey applications, to wit: (1) Dualfrequency radar altimeter to measure elevation over land surfaces; (2) Dual-frequency Precipitation Radar for Global Precipitation Measurements; (3) Dual ■ frequency synthetic aperture radar used to create two-dimensional images or three-dimensional reconstructions of the object, such as landscape terrain. The RF beamforming platforms are substantially composed of planar arrays of periodic unit cells. Each unit cell traditionally contains one and only one RF radiator in the form of a conducting patch over a return current plane, thus, the simultaneous requirement of spatial coherency and resonance does limit the legacy array to operate in a single RF band. In contrast, the exemplary system can provide M unit cells, each unit cell comprising N x N radiating structures in which each one of N radiators can be arranged to form M interpenetrating phase arrays. With judicious use of RF filtering, each interpenetrating phase array can now transactive on a separate RF band, thus forming an RF composite beamformer in which N interpenetrating arrays, each independent of the others and each ha ving M x M radiating elements, communicate in different spatial directions on different RF bands, simultaneously and a-synchronously; each not interfering with other of N interpenetrating arrays.

[0135] Distinctions between interleaved and interpenetrating. Given a first array comprising geometrical objects, each object having lateral dimensions substantially similar to the separation between said objects, it is impossible to insert an additional object between adjacent objects without violating the fixed separation rule. If additional objects are added to the array, then the array must expand. The array is said to be interleaved and scales substantially linearly with the number of objects.

[0136] Given a second array comprising geometrical objects, each object having lateral dimensions substantially smaller than the separation between said objects, it is possible to insert additional plural objects between existing objects without violating the fixed separation rule. The second array is said to be interpenetrating and scales sub-linearly with number of arrays in the group. [0137] These possibilities are enabled by simply migrating from a single low aspect ratio (patch) radiator per unit cell to N, high aspect ratio, 1 X rod monopole radiators per unit cell, where X substantially represents the wavelength of the center RF frequency band in use.

[0138] Conclusion

[0139] Although example embodiments of the present disclosure are explained in some instances in detail herein, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the present disclosure be limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways.

[0140] It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “ 5 approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, other exemplary embodiments include the one particular value and/or to the other particular value.

[0141] By “comprising” or “containing” or “including” is meant that at least the name compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.

[0142] In describing example embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. It is also to be understood that the mention of one or more steps of a method does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Steps of a method may be performed in a different order than those described herein without departing from the scope of the present disclosure. Similarly, it is also to be understood that the mention of one or more components in a device or system does not preclude the presence of additional components or intervening components between those components expressly identified. [0143] As discussed herein, a “subject” may be any applicable human, animal, or another organism, living or dead, or other biological or molecular structure or chemical environment, and may relate to particular components of the subject, for instance, specific tissues or fluids of a subject (e.g., human tissue in a particular area of the body of a living subject), which may be in a particular location of the subject, referred to herein as an “area of interest” or a “region of interest.”

[0144] It should be appreciated that, as discussed herein, a subject may be a human or any animal. It should be appreciated that an animal may be a variety of any applicable type, including, but not limited thereto, mammal, veterinarian animal, livestock animal or pet type animal, etc. As an example, the animal may be a laboratory animal specifically selected to have certain characteristics similar to humans (e.g., rat, dog, pig, monkey), etc. It should be appreciated that the subject may be any applicable human patient, for example.

[0145] The term “about,” as used herein, means approximately, in the region of, roughly, or around. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 10%. In one aspect, the term “about” means plus or minus 10% of the numerical value of the number with which it is being used. Therefore, about 50% means in the range of 45%-55%. Numerical ranges recited herein by endpoints include all numbers and fractions subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.90, 4, 4.24, and 5).

[0146] Similarly, numerical ranges recited herein by endpoints include subranges subsumed within that range (e.g., 1 to 5 includes 1-1.5, 1.5-2, 2-2.75, 2.75-3, 3-3.90, 3.90-4, 4-4.24, 4.24-5, 2-5, 3-5, 1-4, and 2-4). It is also to be understood that all numbers and fractions thereof are presumed to be modified by the term “about.”

[0147] Some references, which may include various patents, patent applications, and publications, are cited in a reference list and discussed in the disclosure provided herein. The citation and/or discussion of such references is provided merely to clarify the description of the present disclosure and is not an admission that any such reference is “prior art” to any aspects of the present disclosure described herein. In terms of notation, “[n]” corresponds to the nth 10 references in the list. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference.

[0148] References

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[21] Nicholas P. Lawrence, Christophe Furneaux and Derek Abbott and is entitled “Wideband Substrate-Integrated Monopole Antenna” Journal Microwave and Optical Technology Letter, August 2016, D01:10.1002/mop.29925.

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[23] Aboulnasr Hassanien and Sergiy A. Vorobyov, “Phased-MIMO Radar: A Tradeoff Between Phased- Array and MIMO Radars” IEEE Transactions on Signal Processing, Vol. 58, pp. 3137-3151, (2010). DOI: 10.1109/TSP.2010.2043976.

[24] Anastasios Deligiannis, Sangarapillai Lambotharan and Jonathon A. Chambers, “Beamforming for Fully-Overlapped Two-Dimensional Phased-MIMO Radar,” 2015 IEEE Radar Conference (RadarCon), DOI: 10.1109/RADAR.2015.7131068, which are incorporated by reference herein.