System and method for signaling communication with expandable modular network nodes

Abstract

To provide a system and method for signaling communication with suitable, expandable, modular network nodes. [Solution] The radio frequency (RF) aperture includes an interface board. An array of conductive tapered projections is located on the front side of the interface printed circuit board and has a base that extends away from the front side of the interface printed circuit board. The RF circuit is located on the back side of the interface board and is electrically connected to the conductive tapered projections. The RF circuit is located on the rear side of the interface board and is electrically connected to the array of conductive tapered projections on the front side of the interface board.

Description

[Background technology]

[0001] This application claims the interests of U.S. Provisional Application No. 62 / 842,816, filed on 3 May 2019 and titled "SYSTEMS AND METHODS FOR SIGNAL COMMUNICATION WITH SCALABLE, MODULAR NETWORK NODES," U.S. Provisional Application No. 62 / 839,131, filed on 26 April 2019 and titled "SYSTEMS AND METHODS FOR SIGNAL COMMUNICATION WITH SCALABLE, MODULAR NETWORK NODES," and U.S. Provisional Application No. 62 / 839,125, filed on 26 April 2019 and titled "SYSTEMS AND METHODS FOR SIGNAL COMMUNICATION WITH SCALABLE, MODULAR NETWORK NODES." U.S. Provisional Application No. 62 / 842,816, filed on 3 May 2019, is incorporated herein by reference in its entirety. U.S. Provisional Application No. 62 / 839,131, filed on 26 April 2019, is incorporated herein by reference in its entirety. U.S. Provisional Application No. 62 / 839,125, filed on 26 April 2019, is incorporated herein by reference in its entirety.

[0002] (background) The following pertains to the fields of radio frequency (RF) technology, RF transmission technology, RF receiver technology, RF transceiver technology, broadband RF transmission, receiver, and / or transceiver technology, RF communications technology, and related technologies.

[0003] Steinbrecher's U.S. Patent No. 7,420,522, titled "Electromagnetic Radiation Interface System and Method," discloses a broadband RF aperture as follows: "An electromagnetic radiation interface suitable for use with radio frequencies is provided. The surface comprises a plurality of metallic conical bristles. A plurality of corresponding termination sections are provided such that each bristle is terminated with the termination section. The termination sections may have electrical resistance to capture substantially all of the electromagnetic wave energy received by each individual bristle, thereby preventing reflection from the interface surface. Each termination section may also include an analog-to-digital converter for converting the energy from each bristle into a digital word. The bristles may be mounted on a ground surface having a plurality of holes through them. A plurality of coaxial transmission lines may extend through the ground surface to interconnect the plurality of bristles to the plurality of termination sections." Some improvements are disclosed herein. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] U.S. Publication No. 7,420,522 [Overview of the project] [Means for solving the problem]

[0005] (Brief summary) According to some illustrative embodiments disclosed herein, the radio frequency (RF) aperture comprises an interface substrate having a front side and a back side; an array of conductive tapered projections having a base disposed on the front side of the interface substrate and extending away from the front side of the interface substrate, wherein the conductive tapered projections are hollow and one or more electronic components are disposed inside the hollow conductive tapered projections; and an RF network disposed on the back side of the interface substrate and electrically connected to the array of conductive tapered projections on the front side of the interface substrate.

[0006] According to some illustrative embodiments disclosed herein, the RF opening comprises an interface substrate having a front side and a back side; an array of conductive tapered projections having a base located on the front side of the interface substrate and extending away from the front side of the interface substrate; and an RF network located on the back side of the interface substrate and electrically connected to the array of conductive tapered projections on the front side of the interface substrate. The conductive tapered projections of the array of conductive tapered projections include a first set of conductive tapered projections of equal size arranged in a linear array, and a second set of conductive tapered projections arranged between the conductive tapered projections of the first set of conductive tapered projections.

[0007] According to some illustrative embodiments disclosed herein, the RF opening comprises an interface substrate having a front side and a back side; an array of conductive tapered projections having a base disposed on the front side of the interface substrate and extending away from the front side of the interface substrate; a dielectric filler disposed between the conductive tapered projections; and an RF network disposed on the back side of the interface substrate and electrically connected to the array of conductive tapered projections on the front side of the interface substrate.

[0008] According to some illustrative embodiments disclosed herein, the RF aperture comprises an interface substrate having a front side and a back side; an array of faceted conductive tapered projections having a base located on the front side of the interface substrate and extending away from the front side of the interface substrate; and an RF network electrically connected to the aperture pixels, located on the back side of the interface substrate and comprising differential RF receiving and / or transmitting elements defined by neighboring facets of neighboring pairs of faceted conductive tapered projections.

[0009] According to some illustrative embodiments disclosed herein, the RF aperture comprises an interface substrate having a front side and a back side; an array of solid conductive tapered projections having a base disposed on the front side of the interface substrate and extending away from the front side of the interface substrate, the base having a threaded opening; a threaded fastener passing through the opening in the interface substrate and screwed into the threaded opening of the base of the solid conductive tapered projections, thereby fixing the solid conductive tapered projections to the interface substrate; and an RF network disposed on the back side of the interface substrate and electrically connected to aperture pixels having differential RF receiving and / or transmitting elements defined by neighboring pairs of solid conductive tapered projections.

[0010] According to some illustrative embodiments disclosed herein, the RF aperture comprises an interface substrate having a front side and a back side, and an array of hollow conductive tapered projections having a base disposed on the front side of the interface substrate and extending away from the front side of the interface substrate, wherein the hollow conductive tapered projections have a central cylindrical support disposed inside the hollow projections, the central cylindrical support having a threaded opening, the array of hollow conductive tapered projections, a threaded fastener passing through the opening in the interface substrate and screwed into the threaded opening of the central cylindrical support of the hollow conductive tapered projections, thereby fixing the hollow conductive tapered projections to the interface substrate, and an RF network disposed on the back side of the interface substrate and electrically connected to aperture pixels comprising differential RF receiving and / or transmitting elements defined by neighboring pairs of hollow conductive tapered projections.

[0011] According to some illustrative embodiments disclosed herein, an RF aperture comprises an interface substrate having a front side and a back side; an array of conductive tapered projections having a base disposed on the front side of the interface substrate and extending away from the front side of the interface substrate, wherein the conductive tapered projections have a central cylindrical support disposed inside the hollow projection; and an RF network disposed on the back side of the interface substrate and electrically connected to aperture pixels having differential RF receiving and / or transmitting elements defined by neighboring pairs of conductive tapered projections. Each conductive tapered projection includes a dielectric structure having a tapered receiver; and a conductive tapered plate meshing into the tapered receiver of the dielectric structure, defining the facets of the conductive tapered projection.

[0012] According to some illustrative embodiments disclosed herein, the RF aperture comprises an interface substrate having a front side and a back side; an array of conductive tapered projections having a base disposed on the front side of the interface substrate and extending away from the front side of the interface substrate, wherein the conductive tapered projections comprise an array of conductive tapered projections having a central cylindrical support disposed inside the hollow projections; an RF network disposed on the back side of the interface substrate and electrically connected to aperture pixels comprising differential RF receiving and / or transmitting elements defined by neighboring pairs of conductive tapered projections; and a radome having recesses in the shape of the tapered projections. The conductive tapered projections may comprise sheet metal punched into the recesses in the shape of the tapered projections and disposed within the recesses in the shape of the tapered projections.

[0013] According to some illustrative embodiments disclosed herein, the RF aperture includes:

[0014] According to some illustrative embodiments disclosed herein, an RF aperture configured to operate at a certain RF wavelength comprises an interface substrate having a front side and a back side; an array of conductive tapered projections having a base positioned on the front side of the interface substrate and extending away from the front side of the interface substrate; an RF network positioned on the back side of the interface substrate and electrically connected to an aperture pixel having a differential RF receiving and / or transmitting element defined by neighboring pairs of conductive tapered projections; and standoffs having a height above the RF wavelength, wherein the faceted conductive tapered projections are mounted on individual standoffs.

[0015] According to some illustrative embodiments disclosed herein, the RF aperture comprises an interface substrate which is a dielectric substrate or printed circuit board (PCB) without a ground surface, having a front side and a back side; an array of conductive tapered projections having a base located on the front side of the interface substrate and extending away from the front side of the interface substrate; and an RF network located on the back side of the interface substrate and electrically connected to aperture pixels having differential RF receiving and / or transmitting elements defined by neighboring pairs of conductive tapered projections. The RF network comprises a PCB with a ground surface oriented perpendicular to the interface substrate, and RF components mounted on the vertical PCB.

[0016] According to some illustrative embodiments disclosed herein, the RF aperture comprises the following:

[0017] According to some illustrative embodiments disclosed herein, the RF aperture comprises the following:

[0018] According to some illustrative embodiments disclosed herein, the RF aperture comprises the following: [Brief explanation of the drawing]

[0019] Any quantitative dimensions shown in the drawings shall be understood as non-limiting illustrative examples. Unless otherwise indicated, the drawings are shown as if any aspect of the drawings were at an exact scale, rather than at an exact scale, and the scales shown shall be understood as non-limiting illustrative examples.

[0020] [Figure 1] Figures 1 and 2 schematically illustrate the front and side cross-sectional views, respectively, of an exemplary RF aperture implemented as a differential compartmentalized aperture (DSA). [Figure 2] Figures 1 and 2 schematically illustrate the front and side cross-sectional views, respectively, of an exemplary RF aperture implemented as a differential compartmentalized aperture (DSA).

[0021] [Figure 3] Figure 3 schematically shows a block diagram of a single QUAD subassembly of the DSA of FIGS. 1-4.

[0022] [Figure 4] Figure 4 schematically illustrates a front view of the interface printed circuit board (i-PCB) of the DSA of FIGS. 1-3, including vias and mounting holes, and schematically shows the locations of the balun and register pads.

[0023] [Figure 5] Figure 5 schematically illustrates a rear view of the enclosure of the DSA of FIGS. 1-4, including a schematically shown RF connection, a control unit, and a power connector.

[0024] [Figure 6] Figure 6 schematically illustrates a side cross-sectional view of an embodiment with conductive tapered protrusions, in addition to a schematic representation of the connection of the balanced ports of the chip balun between two adjacent conductive tapered protrusions.

[0025] [Figure 7] Figures 7-10 schematically illustrate additional embodiments of the conductive tapered protrusions. [Figure 8] Figures 7-10 schematically illustrate additional embodiments of the conductive tapered protrusions. [Figure 9] Figures 7-10 schematically illustrate additional embodiments of the conductive tapered protrusions. [Figure 10] Figures 7-10 schematically illustrate additional embodiments of the conductive tapered protrusions.

[0026] [Figure 11] Figures 11 and 12 show embodiments in which the conductive tapered protrusion of the RF aperture is hollow and one or more electronic components are disposed inside the hollow conductive tapered protrusion. [Figure 12]Figures 11 and 12 show embodiments in which the conductive tapered projection of the RF aperture is hollow, and one or more electronic components are arranged inside the hollow conductive tapered projection.

[0027] [Figure 13] Figure 13 schematically illustrates an exploded view of another illustrative RF aperture assembly.

[0028] [Figure 14] Figures 14-17 schematically illustrate several illustrative layouts of conductive tapered projections across the area of ​​the RF aperture. [Figure 15] Figures 14-17 schematically illustrate several illustrative layouts of conductive tapered projections across the area of ​​the RF aperture. [Figure 16] Figures 14-17 schematically illustrate several illustrative layouts of conductive tapered projections across the area of ​​the RF aperture. [Figure 17] Figures 14-17 schematically illustrate several illustrative layouts of conductive tapered projections across the area of ​​the RF aperture.

[0029] [Figure 18] Figure 18-24 shows a side cross-sectional view of an RF aperture embodiment that employs dielectric filler material positioned between neighboring conductive tapered projections to adjust RF capture performance for transmission and / or reception operations. [Figure 19] Figure 18-24 shows a side cross-sectional view of an RF aperture embodiment that employs dielectric filler material positioned between neighboring conductive tapered projections to adjust RF capture performance for transmission and / or reception operations. [Figure 20] Figure 18-24 shows a side cross-sectional view of an RF aperture embodiment that employs dielectric filler material positioned between neighboring conductive tapered projections to adjust RF capture performance for transmission and / or reception operations. [Figure 21]Figure 18-24 shows a side cross-sectional view of an RF aperture embodiment that employs dielectric filler material positioned between neighboring conductive tapered projections to adjust RF capture performance for transmission and / or reception operations. [Figure 22] Figure 18-24 shows a side cross-sectional view of an RF aperture embodiment that employs dielectric filler material positioned between neighboring conductive tapered projections to adjust RF capture performance for transmission and / or reception operations. [Figure 23] Figure 18-24 shows a side cross-sectional view of an RF aperture embodiment that employs dielectric filler material positioned between neighboring conductive tapered projections to adjust RF capture performance for transmission and / or reception operations. [Figure 24] Figure 18-24 shows a side cross-sectional view of an RF aperture embodiment that employs dielectric filler material positioned between neighboring conductive tapered projections to adjust RF capture performance for transmission and / or reception operations.

[0030] [Figure 25] Figure 25 shows another illustrative RF aperture assembly.

[0031] [Figure 26] Figure 26 shows an RF opening with a conductive tapered projection positioned on a curved (e.g., radial) surface.

[0032] [Figure 27] Figure 27 schematically illustrates a network employing DSA.

[0033] [Figure 28] Figure 28 schematically shows a suitable processing node that can be used in conjunction with the embodiment shown in Figure 25.

[0034] [Figure 29] Figure 29-36 illustrates an embodiment of a conductive tapered projection, which is a solid projection. [Figure 30] Figure 29-36 illustrates an embodiment of a conductive tapered projection, which is a solid projection. [Figure 31] Figure 29-36 illustrates an embodiment of a conductive tapered projection, which is a solid projection. [Figure 32] Figure 29-36 illustrates an embodiment of a conductive tapered projection, which is a solid projection. [Figure 33] Figure 29-36 illustrates an embodiment of a conductive tapered projection, which is a solid projection. [Figure 34] Figure 29-36 illustrates an embodiment of a conductive tapered projection, which is a solid projection. [Figure 35] Figure 29-36 illustrates an embodiment of a conductive tapered projection, which is a solid projection. [Figure 36] Figure 29-36 illustrates an embodiment of a conductive tapered projection, which is a solid projection.

[0035] [Figure 37] Figures 37-39 illustrate several alternative faceted conductive tapered projection geometries. [Figure 38] Figures 37-39 illustrate several alternative faceted conductive tapered projection geometries. [Figure 39] Figures 37-39 illustrate several alternative faceted conductive tapered projection geometries.

[0036] [Figure 40] Figure 40-41 illustrates an embodiment with a hollow conductive tapered projection. [Figure 41] Figure 40-41 illustrates an embodiment with a hollow conductive tapered projection.

[0037] [Figure 42] Figures 42-46 illustrate an embodiment having a conductive tapered projection, which includes a dielectric structure and a tapered plate. [Figure 43] Figures 42-46 illustrate an embodiment having a conductive tapered projection, which includes a dielectric structure and a tapered plate. [Figure 44] Figures 42-46 illustrate an embodiment having a conductive tapered projection, which includes a dielectric structure and a tapered plate. [Figure 45] Figures 42-46 illustrate an embodiment having a conductive tapered projection, which includes a dielectric structure and a tapered plate. [Figure 46] Figures 42-46 illustrate an embodiment having a conductive tapered projection, which includes a dielectric structure and a tapered plate.

[0038] [Figure 47] Figure 47-49 illustrates the mounting portion of the conductive tapered projection shown in Figure 42-46 on the interface substrate. [Figure 48] Figure 47-49 illustrates the mounting portion of the conductive tapered projection shown in Figure 42-46 on the interface substrate. [Figure 49] Figure 47-49 illustrates the mounting portion of the conductive tapered projection shown in Figure 42-46 on the interface substrate.

[0039] [Figure 50] Figure 50-54 illustrates an embodiment of a conductive tapered projection constructed by bending a cutout in a sheet metal. [Figure 51] Figure 50-54 illustrates an embodiment of a conductive tapered projection constructed by bending a cutout in a sheet metal. [Figure 52] Figure 50-54 illustrates an embodiment of a conductive tapered projection constructed by bending a cutout in a sheet metal. [Figure 53] Figure 50-54 illustrates an embodiment of a conductive tapered projection constructed by bending a cutout in a sheet metal. [Figure 54] Figure 50-54 illustrates an embodiment of a conductive tapered projection constructed by bending a cutout in a sheet metal.

[0040] [Figure 55] Figure 55 illustrates an embodiment having a conductive tapered projection constructed by punching a sheet metal into a radome that defines the shape of the tapered projection.

[0041] [Figure 56] Figure 56 illustrates potential RF interference within the DSA caused by the interface substrate with a ground contact surface.

[0042] [Figure 57] Figure 57 illustrates one embodiment in which a standoff is employed to mitigate the potential RF interference described with reference to Figure 56.

[0043] [Figure 58] Figures 58-63 illustrate an embodiment that employs an RF network with a vertical printed circuit board (PCB) to mitigate potential RF interference, as described with reference to Figure 56. [Figure 59] Figures 58-63 illustrate an embodiment that employs an RF network with a vertical printed circuit board (PCB) to mitigate potential RF interference, as described with reference to Figure 56. [Figure 60] Figures 58-63 illustrate an embodiment that employs an RF network with a vertical printed circuit board (PCB) to mitigate potential RF interference, as described with reference to Figure 56. [Figure 61] Figures 58-63 illustrate an embodiment that employs an RF network with a vertical printed circuit board (PCB) to mitigate potential RF interference, as described with reference to Figure 56. [Figure 62] Figures 58-63 illustrate an embodiment that employs an RF network with a vertical printed circuit board (PCB) to mitigate potential RF interference, as described with reference to Figure 56. [Figure 63] Figures 58-63 illustrate an embodiment that employs an RF network with a vertical printed circuit board (PCB) to mitigate potential RF interference, as described with reference to Figure 56.

[0044] [Figure 64] Figure 64 illustrates an exploded view of the DSA, including the radome and vertical PCB as described with reference to Figures 58-63.

[0045] [Figure 65] Figure 65 illustrates the five-sided enclosure or housing of the DSA embodiment shown in Figure 64.

[0046] [Figure 66] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 67] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 68] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 69] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 70] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 71] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 72] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 73] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 74] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 75]Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 76] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 77] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 78] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 79] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 80] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Figure 81] Figures 66-81 illustrate various embodiments of an RF network that can be appropriately used in conjunction with the DSA embodiments disclosed herein. [Modes for carrying out the invention]

[0047] (Detailed explanation) Referring to Figures 1 and 2, an illustrative front and side section view of an RF aperture is shown, which includes an interface printed circuit board (i-PCB) 10 having a front side 12 and a back side 14, and an array of conductive tapered projections 20 having a base 22 positioned on the front side 12 of the i-PCB 10 and extending away from the front side 12 of the i-PCB 10. The illustrative i-PCB 10 is shown in Figure 1 as having dimensions of 5 inches x 5 inches, but this is only a non-limiting illustrative embodiment of a small RF aperture. Figure 1 shows a front view of the RF aperture, accompanied in the upper left by an inset showing a perspective view of one conductive tapered projection 20. This illustrative embodiment of the conductive tapered projection 20 has a square cross-section with a larger square base 22 and a vertex that does not extend to a full tip but rather terminates at a flat vertex 24 (in other words, the conductive tapered projection 20 in the inset has a frustoconical shape). This is merely an illustrative example, and more generally, the conductive tapered projection 20 can have any type of cross-section (e.g., square as in the inset, or circular, or hexagonal, or octagonal, etc.). The vertex 24 can be flat as in the embodiment of the inset, or it can reach an acute point, or it can be rounded, or it can have some other vertex geometric shape. The tapering rate as a function of height (i.e., the distance "above" the base 22 when the vertex 24 is at its maximum "height") can be constant, as in the embodiment of the inset, or the tapering rate can be variable with height. For example, the tapering rate can increase with increasing height to form a projection with a rounded apex, or decrease with increasing height to form a projection with a more pointed tip. Similarly, as shown in most detail in Figure 1, the illustrative array of conductive tapered projections 20 is a linear array with regular rows and orthogonal regular columns; however, the array may have other symmetries, such as hexagonal symmetry, octagonal symmetry, etc.In the illustrative embodiment shown in the inset, the square base 22 and square vertex 24 lead to a conductive tapered projection 20 having four flat, inclined side walls 26. However, other side wall shapes are also conceivable. For example, if the base and vertex are circular (or if the base is circular and the vertex reaches a certain point), the side walls may be inclined or tapered cylinders, with six inclined side walls in relation to the hexagonal base and hexagonal or pointed vertex.

[0048] Continuing with reference to Figures 1 and 2, and further with reference to Figure 3, the RF aperture further comprises an RF network including, in an illustrative embodiment, a chip balun 30 mounted on the back side 14 of the i-PCB 10. Each chip balun 30 is electrically connected to two neighboring conductive tapered projections of an array of conductive tapered projections via an electrical feedthrough 32 that passes through the i-PCB 10, through a balanced port P B Each chip balun 30 also has an unbalanced port P that connects to the rest of the RF network. U (See Figures 3 and 6). The illustrative RF network further includes the unbalanced port P of the chip balun 30. U It includes an RF power divider / coupler 40 for coupling the outputs from. As seen in Figure 3, the illustrative electrical configuration of the RF network is an unbalanced port P U A first-level 1x2 RF power divider / coupler 401 combines the pairs of power dividers and couplers, and a second-level 1x2 RF power divider / coupler 402 combines the outputs of the pairs of first-level RF power dividers / couplers 401. This is merely an illustrative approach, and other configurations are possible, such as using 1x3 (combining 3 lines), 1x4 (combining 4 lines), or higher-level coupled RF power dividers / couplers, or various combinations thereof. The illustrative RF network further includes each unbalanced port P of the chip balun 30. UThe signal conditioning circuit 42 is inserted between the first level 1x2 power divider 401 and the signal conditioning circuit 42 connected to each unbalanced port and includes an RF transmission amplifier T, an RF reception amplifier R, and an RF switching network including a switch RFS configured to switch between a transmission mode in which the RF transmission amplifier T and the unbalanced port are operably connected and a reception mode in which the RF reception amplifier R and the unbalanced port are operably connected.

[0049] Continuing with reference to Figures 1-3, and further with reference to Figures 4 and 5, a compact design (e.g., a depth of 3 inches in the non-limiting illustrative embodiment of Figure 3) is achieved, in part, by employing one or more printed circuit boards (PCBs) including at least an i-PCB 10. In the illustrative embodiment shown in Figure 3, a chip balun 30 is mounted on the back side 14 of the i-PCB 10. Optionally, other electronic components may also be mounted on the back side of the i-PCB 10, with an array of conductive tapered projections 20 on its front side 12. However, there may be insufficient occupied area on the i-PCB 10 to mount all the electronic components of the RF network. In the illustrative embodiment, this is addressed by providing a second printed circuit board 50 positioned in parallel with the i-PCB 10 and facing the back side 14 of the i-PCB 10. In other words, the second printed circuit board 50 is located on the (back) side 14 of the i-PCB 10 opposite to the (front) side 12 where the conductive tapered projections 20 are located. The RF network comprises electronic components mounted on the second printed circuit board 50, which may also be referred to herein as a signal conditioning PCB or SC-PCB 50, and additionally, or alternatively, electronic components mounted on the i-PCB 10 (typically on the back side 14 of the i-PCB, but it is also conceivable that the RF network components be mounted on the front side of the i-PCB in the field space between the conductive tapered projections 20 (not shown)). If the SC-PCB 50 is provided, as shown in Figure 2, it is appropriately fixed parallel to the i-PCB 10 by standoffs 54, and a single-ended feedthrough 52 is provided for electrically interconnecting the i-PCB 10 and the SC-PCB 50 (see Figure 3). If the RF network cannot be fitted onto the occupied area of ​​the two PCBs 10, 50, a third (and optionally a fourth, and further) PCB may be added to accommodate the components of the RF network (not shown).

[0050] Figure 4 shows a front view of the i-PCB10, including vias and mounting holes, and schematically illustrates the locations of the balun 30 and register pads as shown in the legend in Figure 4. (The registers are used to terminate the unused side of the pyramid to help reduce the radar cross-section.)

[0051] Referring to Figure 2, and further to Figure 5, the illustrative RF opening has an enclosure 58 fixed around the periphery of the i-PCB 10 such that the periphery of the i-PCB 10 encloses the RF network. This is only one illustrative arrangement, and other designs are conceivable, for example, both PCBs 10 and 50 may be located inside the enclosure (however, such an enclosure should not include an RF shielding extending forward to block the area of ​​the RF opening). Figure 5 schematically illustrates the rear view of an RF aperture enclosure 58, showing a schematicly represented RF connector (or port) 60 (also shown or displayed in Figures 2 and 3), control electronics 62 (e.g., illustrative phased array beam steering electronics 63, shown as a non-limiting figure, which may be mounted outside the enclosure 58 and / or located inside the enclosure 58 to provide useful RF shielding), and a power connector 64 for providing power to operate the active components of the RF network (e.g., operating power for an active RF transmission amplifier T, an active RF reception amplifier R, and a switch RFS). The specific arrangement of the various components 60, 62, 63, 64 across the rear surface area of ​​the enclosure can vary widely from that shown in Figure 5, and these components may be located elsewhere, for example, the RF connector 60 may be located alternatively at the edge of the RF aperture. It should also be understood that if the RF aperture is constructed in conjunction with some other component or system, for example, if the RF aperture is used as an RF transmission element and / or receiving element in a mobile ground station, maritime radio, or unmanned aerial vehicle (UAV), the enclosure 58 may be replaced by having an RF aperture built into the housing of the mobile ground station, maritime radio, UAV airframe, etc. In such cases, the RF connector 60 may also be replaced by a wired connection to the mobile ground station, maritime radio, UAV electronics, etc.

[0052] Referring particularly to Figure 3, an illustrative electrical configuration for an illustrative RF network is shown. In this non-limiting illustrative embodiment, the array of conductive tapered projections 20 is assumed to be a 5 × 5 array of conductive tapered projections 20, as shown in Figures 1 and 4. The balanced port P of the tip balun 30 BThe array connects adjacent (i.e., neighboring) pairs of conductive tapered projections 20 to receive a differential RF signal between two adjacent conductive tapered projections 20 (in receiving mode, or alternatively, in transmission mode, to apply a differential RF signal between two adjacent conductive tapered projections 20). As detailed in Steinbrecher's U.S. Patent No. 7,420,522 (which is incorporated herein by reference as a whole), the tapering of the conductive tapered projections 20 presents separation between two conductive tapered projections 20, which varies with "height," i.e., with respect to the distance "above" the base 22 of the conductive tapered projections 20. This provides broadband RF capture, as a range of RF wavelengths corresponding to the range of separation between adjacent conductive tapered projections 20 introduced by the tapering can be captured. The RF aperture is therefore a differential compartmentalized aperture (DSA) and has differential RF receiving (or RF transmitting) elements corresponding to adjacent pairs of conductive tapered projections 20. These differential RF receiving (or transmitting) elements are referred to herein as aperture pixels. With respect to an illustrative linear 5×5 array of adjacent conductive tapered projections 20, this means that there are four aperture pixels along each row (or column) of five conductive tapered projections 20. More generally, with respect to a linear array of projections having N rows (or columns) of conductive tapered projections 20, there will be N-1 corresponding pixels along the row (or column). Figure 3 shows a QUAD subassembly, which is an interconnection of rows (or columns) of four pixels. Since there are four rows and four columns, this leads to 4×4 or 16 such QUAD subassemblies. Register pads are used as terminations for the unused edges of the surrounding pyramids to prevent unwanted reflections. Without the resistors mounted via the resistor pads, their surfaces would remain floating, re-radiating incident RF energy and potentially causing an enhanced radar cross-section.

[0053] In the illustrative embodiment shown in Figure 3, each QUAD subassembly has a 1×2 second level. The RF power divider / coupler 402 connects to the RF connector 60 on the rear side of the enclosure 58. Thus, as seen in Figure 5, there are eight RF connectors for the eight QUAD subassemblies shown in Figures 4 and 5, such as row QUAD subassemblies N1, N2, N3, N4 and column QUAD subassemblies M1, M2, M3, M4. The Gnd(N) row and Gnd(M) column are circuit grounds to allow a common path for current flow from the captured RF energy along the periphery of the pyramid. The use of QUAD subassemblies allows for a high level of flexibility in RF coupling to the RF aperture. For example, the illustrative phased array beam steering electronics 63 provides appropriate phase shift for row QUAD subassemblies N1, N2, N3, N4.

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[0054] The electronic device described employing PCBs 10, 50, a chip balun 30, and active signal conditioning components (e.g., an active transmission amplifier T and a receiving amplifier R) advantageously allows the RF aperture to be fabricated in a small and lightweight form. As described below, embodiments of the conductive tapered projection 20 further facilitate the provision of a small and lightweight broadband RF aperture.

[0055] Figure 6 shows a side cross-sectional view of one illustrative embodiment in which each conductive tapered projection 20 is fabricated as a dielectric tapered projection 70 with a conductive layer 72 disposed on the surface of the dielectric tapered projection 70. The dielectric tapered projection may consist of an electrically insulating plastic or ceramic material such as acrylonitrile butadiene styrene (ABS), polycarbonate, etc., and may be manufactured by injection molding, three-dimensional (3D) printing, or other suitable techniques. The conductive layer 72 may be any suitable conductive material such as copper, copper alloys, silver, silver alloys, gold, gold alloys, aluminum, aluminum alloys, or may consist of a layered stack of different conductive materials, and may be coated onto the dielectric tapered projection 70 by vacuum evaporation, RF sputtering, or any other vacuum deposition technique. Figure 6 shows one embodiment in which a soldering point 74 is used to electrically connect the conductive layer 72 of each dielectric tapered projection 20 to its corresponding electrical feedthrough 32 passing through the i-PCB 10. Figure 6 also shows the balancing port P of one tip balun 30 between two adjacent conductive tapered projections 20 via a soldering point 76. B The illustrative connection is also shown.

[0056] Figures 7 and 8 show an exploded side section and perspective view, respectively, of one embodiment in which dielectric tapered projections 70 are integrally contained within a dielectric plate 80. The conductive layer 72 coats each dielectric tapered projection 70 but has insulating gaps 82 that provide galvanic insulation between neighboring dielectric tapered projections 20. The insulating gaps 82 can be formed after coating the conductive layer 72 by etching the coating away from the plate 80 between the conductive tapered projections 20, thereby DC-insulating the conductive tapered projections from each other. Alternatively, the insulating gaps 82 can be defined before coating by depositing a mask material (not shown) on the plate 80 between the conductive tapered projections 20 so that the coating does not coat the plate within the insulating gaps 82 between the conductive tapered projections, thereby DC-insulating the conductive tapered projections from each other. As can be seen in the perspective view of Figure 8, the dielectric plate 80 consequently covers (and thus closes) the surface of the i-PCB 10, with the conductive tapered projection 20 extending away from the dielectric plate 80.

[0057] Referring particularly to Figure 7, in one approach for electrical interconnection, a through-hole 82 passes through the illustrative plate 80 and the underlying i-PCB 10, and a rivet, screw, or other conductive fastener 32' passes through the through-hole 82 (note that Figure 7 is an exploded view) and, therefore, when installed, forms an electrical feedthrough 32' that passes through the i-PCB 10. (Note that the perspective view in Figure 8 is simplified and does not depict the fastener 32'.) The use of the dielectric plate 80 with an integrated dielectric tapered projection 70 and combined fastener / feedthrough 32' advantageously allows the conductive tapered projection 20 to be installed without soldering using precise positioning.

[0058] In the embodiment shown in Figure 6-8, the conductive coating 72 is placed on the outer surface of the dielectric tapered projection 70. In this case, the dielectric tapered projection 70 may be hollow or solid.

[0059] Referring to Figures 9 and 10, since the dielectric material is substantially transparent to RF radiation, the conductive coating 72 may instead be coated on the inner surface of the (hollow) dielectric tapered projection 70. Figure 9 shows a side section view of such an embodiment, while Figure 10 shows a perspective view. The embodiments of Figures 9 and 10 again employ a dielectric plate 80 including the dielectric tapered projection 70. As seen in Figure 10, coating the inner surface of the hollow dielectric tapered projection 70 with the conductive coating 72 protects the conductive coating 72 from external contact by the dielectric plate 80 including the integrated dielectric tapered projection 70. This may be useful in environments where weather may be a concern.

[0060] It should be understood that various aspects disclosed are illustrative examples, and that disclosed features may be combined or omitted in various ways in specific embodiments. For example, one of the illustrative examples of the conductive tapered projection 20 or a variation thereof may be adopted without the QUAD subassembly network configuration shown in Figure 2-5. Conversely, the QUAD subassembly network configuration shown in Figure 2-5 or a variation thereof may be adopted without the dielectric / coating configuration for the conductive tapered projection 20. Similarly, the chip balun 30 may or may not be used in specific embodiments.

[0061] Referring to Figures 11 and 12, further embodiments of the multiple sensor elements / pyramids 20 of the DSA102 (e.g., an expandable modular substrate) are described. The sensor elements / pyramids can be formed, for example, as an array on the front side 12 of the circuit board 10 and function as a radiating interface. Each of the sensor elements / pyramids 20 in Figures 11 and 12 includes a plurality of conductive plates 90 (Figure 12) that together form a pyramid, and / or each sensor element / pyramid can be formed from a single plate 91 (Figure 11), for example, wound in a conical manner. In some embodiments, each sensor element / pyramid 20 is hollow, i.e., includes a void 92. The void 92 may be formed by the inner portion of either the plurality of plates 90 and / or the single conical plate 91. This occurs, for example, when the sensor element / pyramid 20 is supported from the outer portion, creating a void 92 in the center. In one embodiment, the plurality of plates 90 of the sensor element / pyramid are close to each other but cannot touch. In other words, the conductive plates of the sensor element / pyramid can form gaps 94 (Figure 12). Similarly, a single conical plate 91 can also have an upper opening or gap 95. Gaps 94, 95 can exist between the plates and / or between the plates and the support of the fixture that contains or holds the plates of the sensor element / pyramid of the DSA. In some embodiments, the sensor element / pyramid 20 can be formed from a solid material. The surfaces 90, 91 of the plates forming the sensor element / pyramid can be used for conductivity (e.g., deep within the skin). In other words, the surface of the sensor element / pyramid 20 can be used to transmit current from, for example, wavelength or RF signals, and the resistance of the sensor element / pyramid can be increased as a result from the current applied to the surface of the sensor element / pyramid (i.e., attenuated). The plates 90, 91 can be formed from any highly conductive material. In some embodiments, the sensor element / pyramidal plates 90, 91 may be formed from any material other than a conductive material, for example, a conductive material may be printed or wound onto a dielectric plate, as shown in Figure 6-10.For example, a conductive material can be spray-coated onto a plate forming a sensor element / pyramid. The thickness of the coating can be varied to achieve a desired skin depth. Embodiments of Figures 11 and 12 further include a conductor or electronic component 96 on the front side 12 of the circuit board 10. Embodiment of Figure 12 further includes a bend 97 defined at the intersection of the lower end of the plate 90 and the conductor or electronic component 96.

[0062] Continuing with Figures 11 and 12, in some embodiments, it is conceivable to utilize voids 92 defined by hollow conductive tapered projections 20 to accommodate one or more electronic components 100 located on the front side 12 of the printed circuit board 10. Electrical vias, i.e., feedthroughs 102, passing through the i-PCB 10, provide electrical communication between the front-side electronics 100 and the electronics / electrical network located on the back side of the i-PCB 10, and / or between the single-ended feedthroughs 52 and the SC-PCB 50 that electrically interconnect the i-PCB 10 (see Figure 3). The embodiment in Figure 12 further includes optional recesses or holes 104 within the surface 12 of the i-PCB 10 that receive the electronic components 100. Other electronic component mounting arrays, such as sockets for integrated circuits (ICs), are also / alternatively conceivable. Advantageously, the hollow conductive tapered projections 20 act as Faraday boxes, protecting the internal electronic components 100 from RF interference. Placing the electronic device 100 inside the hollow conductive tapered projection 20 also provides a smaller design (for example, potentially providing sufficient footprint to eliminate the need for a second PCB 50 shown in Figure 3).

[0063] Referring to Figure 13, in another illustrative RF aperture embodiment, a radio frequency (RF) transparent material 110 covers the sensor element / pyramid (i.e., the conductive tapered projection 20 in other embodiments described herein). The RF transparent material 110 acts as a support / fixture for containing / holding the plate 112 of the DSA element / pyramid trapped within the cover. The plate 112 can be trapped within the cover using or with the help of adhesive 114. In some embodiments, a circuit board can be configured to adhere to a plate (e.g., i-PCB 10). The circuit board can receive the feet or base of the plate, and the plate can optionally be electrically attached to the circuit board (e.g., soldered). In alternative embodiments, the conductive plate 112 can be formed from a printed circuit board. As described above, together, the printed circuit board forming the conductive plate can generate or contain voids (e.g., voids 92 in embodiments of Figures 11 and 12). In some embodiments, the electronic components 110 of the DSA (see Figures 11 and 12) or sensor elements / pyramids are housed within a void and can be combined, for example, in differential mode. Alternatively, the electronic components may be attached to the DSA substrate via screws 116 or holes 118, and the sensor elements / pyramids may be attached directly to each other or to others. In some embodiments, the RF-permeable material cover 110 includes an optional filler 120 filled with a variable dielectric.

[0064] Referring to Figures 14-17, a DSA (e.g., an expandable modular substrate) can include multiple sensor elements / pyramids 20 formed from a conductive plate. Figure 14 shows a top view of one embodiment in which the conductive tapered projections 20 are of equal size and distributed across the i-PCB 10 as a linear array. Figures 15 and 16 show a top and side view, respectively, of one embodiment in which the conductive tapered projections 20 are of equal size and distributed across the i-PCB 10 as a linear array, with smaller, precisely sized conductive tapered projections 20s scattered in the space between the linear arrays. Figure 17 shows one embodiment in which the conductive tapered projections 20 are of equal size but distributed across the i-PCB 10 as something other than a linear array, with, for example, unequal spacing between neighboring conductive tapered projections 20. The sensor elements / pyramids 20, 20s can be formed on the i-PCB 10, for example, as an array, and function as a radiating interface. In some embodiments, the signal acquisition area of ​​the sensor elements / pyramids 20 can be uniformly distributed across the area of ​​the array or radiating interface. This can be achieved, for example, by positioning the center points of the sensor elements / pyramids 20 at equal distances from one another (Figure 14). In alternative embodiments shown in Figures 15 and 16, the center points of a first set of sensor elements / pyramids 20 with a first height H1 (Figure 16) are positioned at equal distances from one another, allowing for uniform distribution of the signal acquisition area across the area of ​​the array or radiating interface, while a second set of sensor elements / pyramids 20s with varying second (or even different) heights H2, H3 can achieve desired propagation or signal acquisition within a randomly located or signal acquisition area defined by the first set of sensor elements / pyramids 20. In other words, the second sets of sensor elements / pyramids 20s do not need to be uniformly spaced apart from one another. In yet another embodiment shown in Figure 17, a first set of sensor elements / pyramids 20 with a first height H1 are positioned at random distances from one another to achieve a desired propagation or signal acquisition. The first set of sensor elements / pyramids 20 with a first height H1 can also be positioned to achieve a desired signal acquisition area.In alternative embodiments (not shown), the first set of sensor elements / pyramids may include a first height H1 that varies to achieve desired propagation or signal acquisition within the signal acquisition area. The first set of sensor elements / pyramids may also have a second set of sensor elements / pyramids scattered throughout, either randomly or organized to achieve desired propagation or signal acquisition within the signal acquisition area, as shown in Figures 15 and 16.

[0065] Referring to Figures 18-20, in some embodiments, the DSA (e.g., an expandable modular substrate) may include a plurality of sensor elements / pyramids 20 formed from conductive plates (or otherwise formed using a metal coating on dielectric protrusions, for example, as described in other embodiments herein). In some embodiments, each of the plurality of sensor elements / pyramids 20 is formed from a single plate wound to produce a conical sensor element / pyramid, and the plurality of conductive plates may be configured to form voids (Figures 18 and 20) or to be solid (Figure 19). As described above, in alternative embodiments, the electronic components of the DSA or sensor elements / pyramids may be housed in the voids in Figures 18 and 20 and combined, for example, in differential mode. Alternatively, the electronic components may be directly attached to the DSA substrate, and the sensor elements / pyramids may be directly attached to each other or to one another. In some embodiments shown in Figures 18-20, the dielectric material may be otherwise configured to surround or form the sensor elements / pyramids 20 of the DSA. In other words, the dielectric material can fill the gap created between the sensor element / pyramid. The dielectric material can form distinctly different layers, as in the embodiments of Figures 18-20. The layers can be formed from different materials, each with a different dielectric constant value. Alternatively, the layers can be formed from the same material, and the dielectric constant of a single material can be varied. For example, as shown in Figure 20, air holes or other dielectric voids may be formed within the dielectric material (e.g., air spaces can be subdivided). The density of air holes or other dielectric voids determines the overall dielectric constant. In one embodiment shown in Figure 20, many air holes or other dielectric voids are formed within the top layer of the dielectric material, which results in a greater match of free space to the dielectric material within the top layer. The second top layer has reduced air holes or other dielectric voids, which decrease the ratio of air holes or dielectric voids to dielectric material. Across each layer of the dielectric material, the ratio of air holes or dielectric voids to dielectric material is reduced (i.e., dielectric lens effect).The dielectric material and the ratio of air holes or dielectric voids to dielectric material can be selected based on the desired propagation of the RF signal through the dielectric material embedded between the sensor elements / pyramids of the DSA. As the signal or wavelength strikes the dielectric material, the propagation changes. In other words, the wavelength of the input signal is shortened. For example, when measuring a voltage difference, the wavelength shortens, or at that time, there is an increase in the voltage difference.

[0066] Referring to Figures 21-23, in some embodiments, the dielectric material can be configured to surround or form the sensor element / pyramid 20 of the DSA. In other words, the dielectric material can fill the gap created between the sensor element / pyramid. In the exemplary embodiment of Figures 21-23, the dielectric material is formed from a single material or from multiple materials that together form a refractive index distribution (e.g., "discontinuous"). In other words, a refractive index distribution type dielectric material exists. As shown in Figure 23, air holes or other dielectric voids can be formed within the refractive index distribution type dielectric material. The density of air holes or other dielectric voids in the refractive index distribution type dielectric material can be varied, for example, based on desired signal propagation through the refractive index distribution type dielectric material.

[0067] Referring to Figure 24, an enlarged view of the graded dielectric of the embodiment in Figure 23 is shown with additional descriptive notation. As shown in Figure 24, the volume fraction of air holes or other dielectric voids and the dielectric material results in the overall dielectric constant. By changing the permeability of the distributed refractive index dielectric material, or by changing the dielectric constant of the distributed refractive index dielectric material filled between the sensor elements / pyramids 20 of the DSA, the propagation of a signal or wavelength changes as it fills the distributed refractive index dielectric material. For example, as shown in Figure 24, a signal may propagate in the first dielectric. In the uppermost part of the distributed refractive index dielectric material, the volume fraction of the dielectric material and the air holes or other dielectric voids have the same dielectric constant (e.g., based on the volume fraction of the material having openings). As the number or volume of air holes or other dielectric voids relative to the dielectric material decreases, the dielectric constant also decreases. Each dielectric has a real part and a complex part. In the complex part, there exists a loss tangent, which is also the dissipation rate. This causes attenuation. The goal is to limit damping by minimizing the complexity of the dielectric material. This is how dielectric materials or composite materials are selected.

[0068] In some embodiments, the sensor element / pyramid of the DSA may include a conductive plate formed from a dielectric material and configured to support the dielectric material. Holes or other dielectric voids may be formed within the dielectric material supported by the conductive plate. Holes or other dielectric voids may be used to vary the effective dielectric constant. The resistivity is used to determine the amount of loss.

[0069] Figure 18-24 shows a dielectric material terminating in front of the apex of the DSA sensor element / pyramid 20, but the dielectric material may extend beyond the apex of the DSA sensor element / pyramid and / or completely encapsulate the DSA sensor element / pyramid.

[0070] In some embodiments, the RF aperture (e.g., DSA) is a modular plate. Multiple DSAs can be selectively combined to form a larger DSA.

[0071] In further variations, DSA could be acoustic or magnetic. Magnetic DSA would allow for efficient magnetic field capture at frequencies as low as tens of hertz, which would potentially minimize propagation. Acoustics would allow DSA to be deployed on submarines and operate in the presence of water.

[0072] Referring to Figure 25, the DSA (e.g., an expandable modular substrate) may include a plurality of sensor elements / pyramids 20 formed from a conductive plate (or otherwise formed as described in various embodiments herein). In one embodiment, the base 10 of the DSA may be formed from a printed circuit board (e.g., the i-PCB described) configured to support the sensor elements / pyramids 20. The circuit board may include a plurality of openings into which baluns (i.e., sensor elements / pyramids 20) are loaded. The circuit board with openings generates shape factors that can be slidably received, for example, on 3D printed shape factors (e.g., blocks, etc.). In other words, the circuit board, together with the baluns, can form a “smart substrate” configured to store the intelligence of the DSA (e.g., using a processing node 900 (see Figure 28)). The smart substrate can be injection molded, for example. The smart substrate can be slidably received on any shape factor. The smart substrate can be manufactured efficiently.

[0073] As shown in Figure 26, a DSA (e.g., an expandable modular substrate) may include a plurality of sensor elements / pyramids 20 formed from a conductive plate (or may be formed otherwise as described in various embodiments herein). While the embodiments described above employ a flat i-PCB 10, in the embodiment of Figure 26, the DSA is formed in a dome shape (or, more generally, having a non-flat or curved surface 130 with a fixed curvature radius, for example, in some more specific embodiments). The dome-shaped DSA of Figure 26 (including sensor elements / pyramids 20 formed along the curved surface 130) can assist in beamforming and beam steering. For example, the DSA may be configured to adhere to a curved surface, such as the exterior of an airplane. Using beamforming, a series of amplitudes may be applied to the sensor elements / pyramids 20 of the DSA, causing lateral loads to be removed and a focused, directional beam to be directed toward the DSA. In other words, the amplitudes of different elements are varied, and the phase shift between adjacent elements can be used to direct the focused beam towards the sensor element / pyramid 20 of the DSA. The illustrative DSA in Figure 26 also includes an optional dielectric material 132 placed between the sensor element / pyramid 20, as illustrated with reference to Figures 18-24, for example.

[0074] Referring to Figure 27, a network 200 is shown that includes an access node 208 (e.g., a signal source / node for detecting signals, etc.) that communicates directly with one DSA 206, and a relay node 204 (e.g., an expandable modular substrate, etc., which includes multiple elements formed as an array and which can function as an electromagnetic radiation interface or other conductive material) that communicates with another DSA 202 (e.g., which may be an interference node, etc., used to relay signal information, etc.).

[0075] Figure 28 shows a schematic representation of a processing node 900, which includes a communication interface 902, a user interface 904, and a processing system 906 with a storage device 908 for storing software 910. The processing node 900 may be used in conjunction with, for example, the DSA shown in Figure 25.

[0076] Several further possible optional aspects and / or extensions are listed below: Antennas, including a single port; Cable transmission lines or transmission lines, not formed as an integrated component of a sensor element; Inner conductors and / or dielectric materials, formed by conductive tapered projections and / or sensors without plates (e.g., sensors are formed as part of a bristle structure); Conductive tapered projections, formed from non-metallic materials or from multiple antennas; Transmission lines, corresponding to multiple conductive tapered projections or antennas; Random signal capture areas; Conductive tapered projections shorter in length compared to the wavelength; Not terminating endoplasmic reticulum in a resistive element matching the impedance of the endoplasmic reticulum (e.g., finding another way to "electrically black out" the signal); Not digitally converting the signal and generating a digital replica of the incident electromagnetic energy; Not generating an active surface that uses an electronic module to control the amplitude of the reflected signal (e.g., amplifying the signal by a coefficient relevant to the actual scale); Pixel partition elements (conductive tapered projections) that do not correspond to a single horizontal / vertical circuit board. Other than RF waves are used (e.g., acoustic or magnetic apertures designed to be equivalent to the RF aperture embodiments described herein). Partition elements are provided, each having a frequency-dependent effective area. A circuit board is formed as part of the partition element. In other words, a partition element of some material is formed that holds or supports a circuit board. The partition element can also be considered a circuit board. A printed partition element, including a printed circuit board formed as part thereof. A printed circuit board is used on or formed using the partition element to induce and / or disperse an RF signal on the remainder of the partition element, etc. In some possible embodiments, the circuit board is terminated in a balanced transmission line. The support substrate (e.g., illustrative i-PCB10) may, alternatively, be formed as part of a conductive tapered projection or partition element. A conductive "seat" or "pad" that is not positioned on the substrate or surrounds the conductive tapered projection or partition element.This refers to a "conductive" seat or pad, such as copper. Non-conductive seats or pads may use materials that provide an acoustic response, such as polymers (in the case of acoustic apertures). Similarly, different properties may also be offered for converting RF waves.

[0077] Several further illustrative implementations of conductive tapered projections are described below. In some embodiments, these are solid elements, as shown in the following examples.

[0078] The protrusion should be firmly mounted on a (flat or curved) surface, and discrete electrical contacts should be formed along each face of the protrusion. The protrusion may be a non-rounded protrusion having at least three faces and three edges connecting the faces. Excessive "play" or uncoupled movement between the interface substrate and the protrusion may result in a decrease in RF performance.

[0079] Referring to Figures 29-31, one embodiment employs a conductive tapered projection 300 and an interface substrate 302 containing a conductive trace 304. The projection 300 is made from a solid conductive material, such as a readily available, high-performance, and cost-effective copper or aluminum metal rod. An illustrative conductive tapered projection 300 has a square pyramidal shape. The projection 300 is held to the substrate 302 by a screw or other threaded fastener 306 that creates a consistent pressure along the base edge. This pressure ensures electrical contact because the conductive trace 304 is slightly higher than the non-conductive elements of the circuit board 302, as seen in Figure 29, and the conductive trace 304 is exposed. A top view of the configuration with the mounted projection 300 is shown in Figure 30, while Figure 31 shows a top view of the interface substrate 302 alone. In this design, the projection 300 has at least one small protrusion (two small protrusions 308 in the illustrative embodiment) that maintains the proper orientation of the projection 300 relative to the conductive surface. The projection 300 has a centering hole 310 which is threaded to receive a screw 306 after the screw has passed through a through hole 312 in the interface substrate 302. This mounting method is independent of the length of the projection 300, and therefore the height of the projection 300 above the surface of the substrate 302 is a free design parameter.

[0080] Referring to Figures 32-35, an embodiment is shown that enables the mounting of a projection that cooperates with a non-PCB interface board (i.e., an interface board that does not contain a printed circuit network). This mounting method uses a sheet product to electrically connect a pyramidal projection to a vertical board below the interface board (not shown in Figures 32-36). Figures 32 and 33 show side and bottom isolated views of a preferred conductive tapered projection 300, which may be the same design as that in Figures 29-31, for example, having the shape of a square pyramidal projection. Here, the projection 300 sits on a conductive (e.g., metal) mounting portion 320. The mounting portion 320 is shown alone in Figure 34, with the projection 308 captured within the hole 322 of the mounting portion 320. The tab 324 (labeled in Figure 34) of the mounting portion is then inserted through the interface board 330 and protrudes, as shown in the exploded perspective view of Figure 35. The screw 306 then proceeds from the back side of the interface board 330 through the individual mounting section 320 into the center hole 310 of the individual projection 300. Again, the mounting section can be used in conjunction with projections 300 of different heights. In this configuration, the mounting section 320 can be designed so that the size of the base is also interchangeable. The size of the mounting section can be freely changed as long as the tab 324 mounted through the interface board 330 is in the same location. As shown in Figure 35, this design allows the interface board 330 to be a non-conductive housing that may contain an electrical network for operating the array of conductive tapered projections 300 in RF transmission mode and / or RF reception mode.

[0081] Referring to Figure 36, another embodiment employs a conductive tapered projection 340 in which the projection 308 of the embodiment in Figures 29-35 is replaced by a recess 348. In this embodiment, the interface substrate 330 of the embodiment in Figures 29-35 is replaced by an interface substrate 350 which includes a projection 352 that engages with the recess 348. In other words, the convex projection 308 is replaced by a hole 348, which in some manufacturing processes results in reduced machining time, and therefore cost, and less material waste. To do so, the interface substrate 350 is designed to supply the projection 352 within itself. The interface substrate 350 may be produced, for example, by injection molding or by additive manufacturing, and in both cases, the inclusion of the projection 352 incurs little or no material or molding cost. For the same strength as the metal projection 308 on the solid metal projection 300, the projection 352 on the non-metallic interface substrate 350 should be larger due to its material composition, but this does not cause any damage as the enlargement of the hole sizes in the mounting portion 320 and projection 340 does not affect cost or performance.

[0082] In the unconventional approach, the use of a projection is eliminated by using a second screw that is offset from the center of the projection to which both screws are fastened. Using two screws requires two threading steps, doubling the number of screws and doubling the time spent fastening.

[0083] Referring to Figures 37-39, in some designs, the conductive tapered projection is faceted with various geometric shapes. As noted, the conductive tapered projection 300, as shown in Figures 30 and 35, is a square pyramid with quadruple rotational symmetry. Figure 37 also shows an embodiment that is a square pyramid but with only double rotational symmetry. This design can accommodate different sensitivities and signal chain complexities along opposing orthogonal polarizations. Figure 38 shows an embodiment in which the conductive tapered projection is a hexahedral (i.e., six-sided) pyramid with sextuple rotational symmetry. The hexagonal structure provides three different polarizations. This is useful when it is necessary to precisely measure or transmit polarization, or when there are more signal chains per unit surface area, thus increasing the transmission power for that same area and reducing noise. Figure 39 shows an embodiment in which the conductive tapered projection is a triahedral (i.e., three-sided) pyramid with triple rotational symmetry. These have properties similar to the hexagonal design in Figure 38. More generally, any configuration in which a geometric shape can be mosaic-like is considered possible, and the simplest of these is a geometric shape that can be mosaic-like by itself.

[0084] Several further illustrative implementations of conductive tapered projections are described below. In these embodiments, the projection is a solid element formed by a plate, for example, as in the following embodiment.

[0085] The manufacture of solid conductive tapered projections uses a substantial amount of internal material that does not affect RF performance, as the electromotive force flows only to a depth equal to the skin depth of the coupled RF radiation at a specific frequency on the outer surface of the projection. Adopting hollow conductive tapered projections can reduce weight, material costs, and processing costs. Hollow projections can be manufactured from sheet products such as conductive plates. In the various embodiments discussed below, the conductive plate may have convex supports, be a freestanding or self-supporting plate, or have concave supports.

[0086] Key attributes for the market acceptance of DSAs include size, weight, power, and cost (SWAP-C) per unit of performance. The use of faceted conductive tapered protrusions (such as those in Figures 30, 35, and 37-39, in contrast to conical protrusions) facilitates the machining of faceted protrusions from solid aluminum or copper material. While convenient, significant materials are used within solid protrusions, and substantial molding times increase both the cost and weight of the DSA. Since electromagnetic waves only penetrate a small depth (i.e., skin depth) into the protrusion, only the first few micrometers of the outer surface need to be conductive. The calculation for skin depth is as follows:

number

number

number

number

number

number

[0087] Referring to Figures 40 and 41, the conductive tapered projection 400 is appropriately milled from a rod material and then processed by a finishing step in which excess material is removed. Figure 40 shows one embodiment of this approach in which a single threaded hole 402 is maintained at the center of the structure, and the remaining material is removed by milling, maintaining a material thickness that is appropriate for mechanical rigidity. Figure 40 shows a central cylindrical support 404 positioned inside the hollow projection 400. The illustrative central cylindrical support 404 has a circular cross-section that extends to the top of the projection, however, this cylindrical support may have a square or rectangular cross-section, which would be quicker to machine, with only a moderate weight disadvantage. This solution reduces the weight of the projection, which increases the molding time and therefore the cost compared to a solid projection, while maintaining the same material cost as a solid projection.

[0088] The conductive tapered projection 400 can be manufactured by casting or additive manufacturing rather than by subtractive milling. Casting reduces manufacturing costs and material waste and is suitable only for high-volume applications. A projection 400 manufactured by casting will likely have a rough surface and be thicker than necessary for mechanical rigidity. With respect to additive manufacturing, the material must be conductive, which limits the applicable techniques. Generally, additive manufacturing is the most expensive, followed by milling, which is the next most expensive and will result in a rough surface.

[0089] The following describes plate-based approaches for manufacturing conductive tapered projections. Three different plate-based approaches are described: an approach using a convex support, an independent, or self-supporting, approach, and an approach utilizing a concave support.

[0090] Referring to Figures 42-48, an embodiment employing a convex support is described. Here, individual conductive (e.g., metallic) tapered plates 420 (shown individually in Figure 42 and in the alternative perspective view) are internally supported by dielectric structures 422, shown in Figures 43 and 44 and in the alternative perspective view. Each conductive tapered plate 420 has a tab 424 at its bottom that electrically extends the plate beyond the base of the projection, creating an electrical connection to an interface substrate (PCB or non-PCB) or a vertical substrate located below the interface substrate, or to some other electronic equipment. Each plate 420 further has a bend 426 within the plate at the point where the projection terminates. The bend 426 allows the plate 420 to advance through the interface substrate at a 90-degree angle. Optional, this bend configuration saves material and provides easier connection. A third feature is an angled extension 428 below the plane of the tapered projection. This angled extension 428 engages with the interface substrate, ensuring sliding and active engagement within the substrate. This also increases the strength at the bent portion 426.

[0091] The conductive tapered plate 420 is supported by a dielectric structure 422 shown in Figures 43 and 44. This structure has four tapered (e.g., "V" shaped) receivers 430 (labeled in Figure 43) (for an exemplary four-sided faceted projection) into which four individual conductive tapered plates 420 mesh. The meshing is by the "V" shaped (or more generally, tapered) receivers 430, which capture the edges of the conductive "V" shaped (more generally, tapered) plate 420, allowing the conductive tapered plate 420 to slide inward as shown in the alternative perspective views of Figures 45 and 46. The conductive tapered plate 420 thus defines the facets of the conductive tapered projection 400. As seen in Figures 44 and 46, the bottom of the dielectric structure 422 has two projections 432 to prevent rotation once mounted on the interface substrate 440 (shown separately in Figure 47) with a aligning positioning hole 442. In addition, there is a hole 444 in the center, which may be threaded to receive a screw or smoothed for a rivet. Fasteners used in this hole proceed from the back of the interface substrate into the support structure, holding the entire assembly together rigidly. Once assembled, the system has the appearance of Figure 48, showing five conductive tapered projections 420, 422 mounted on the upper side, and Figure 49, showing the back side with a protruding tab 424.

[0092] The benefits of this plate-based approach include its substitutability for solid protrusion designs, allowing for application-specific selection of solid or plate-based protrusion types. In addition, plate design configurations are lighter and have significantly lower material costs than solid or hollow protrusion approaches. The dielectric support 422 can be formed by injection molding processes for larger manufacturing volumes or by additive manufacturing for smaller manufacturing volumes. Assembly time is slightly increased due to the step of inserting the plate into the support structure. One RF performance benefit is that electrically insulated plates can provide better cross-polarization isolation compared to solid or hollow protrusions where conductive paths exist between facets.

[0093] In the embodiments described above, an internal structure (i.e., dielectric support 422) was required to support the plate 420. However, complete isolation of the individual sides of the faceted conductive tapered projection, which can lead to mechanical resonance that degrades RF performance, has been demonstrated experimentally. To address these challenges, several illustrative configurations for providing independent projections that do not require an internal structure are disclosed below. These conductive tapered projections are fabricated using sheet materials, further reducing costs. Any of the embodiments may be attached along the entire edge or at points by applying soldering or by creating tabbed connections through which tabs located on one surface slide into notches in adjacent space. Point-based soldering solutions may be ideal because they still allow a considerable amount of cross-polarization isolation while eliminating mechanical resonance by rigidly bonding the surfaces.

[0094] The following illustrative examples show projections that reach a certain point for the sake of simplification. However, reaching a point is not necessary, and for mechanical strength or ease of processing, the projection can be molded to a smaller size so that the top of the projection matches the bottom of the projection.

[0095] One embodiment is shown in Figures 50 and 51. In this embodiment, Figure 51 shows a faceted conductive tapered projection 450 formed by bending a single-piece cutout 452 from a metal sheet, as shown in Figure 50. As shown most in detail in Figure 50 prior to the bending step, the cutout 452 includes four facets 454 (in this embodiment) that abut at a small square vertex facet 456 (or, alternatively, at the vertex as seen in the alternative embodiments of Figures 52-54). The facets 454 of the single-piece cutout 452 are bent at their junctions with the vertex facet 456 (or vertex) to form a faceted conductive tapered projection 450. Each facet 454 includes a tab 458 distal to its junction with the vertex facet 456 (or vertex), which meshes into the interface substrate 460 and electrically connects to the RF network. In the assembled projection 450 in Figure 51, the edges of neighboring facets 454 may optionally be connected by soldering or interlocking tabs (features not shown in Figures 50 and 51). As described above, the vertex facet 456 is optional but can add mechanical strength (if the vertex facet 456 is omitted, the four facets will be integrated at the vertex).

[0096] Referring to Figure 52, a variant embodiment is shown, comprising a faceted conductive tapered projection 470 shown in the lower part of Figure 52 and a corresponding single-piece cutout 472 shown in the upper part of Figure 52. This embodiment omits the vertex facet 456 of the embodiments in Figures 50 and 51 so as to reach a point where there are four facets 474 in this embodiment. In addition, the tab 458 of the embodiments in Figures 50 and 51 is omitted, and at those geographic locations, a bottom plate 476 is attached to one of the facets 474 in the cutout. The bottom plate 476 has an opening 477 for capturing fasteners 478 such as bolt heads or rivets. If bolts are used, the attachment is carried out before the completion of the bend, as once the bend is complete, the inside of the projection 470 becomes inaccessible. Once bent, the projection 470 can be soldered at a point or along its entire edge, or tabbed connections can be used (features not shown). Alternatively, the bottom edge of facet 474 may be soldered to the interface board, or the bottom may be bent to create a tab that rests on the interface board. This variant is lightweight. It can provide good cross-polarization isolation. However, the nature of the bend can lead to variability in RF performance because no mechanical connection exists. In addition, as shown in Figure 52 with a single screw, the pyramid can rotate if only a tight fit is used to electrically attach the faces. Fastening the bottom plate 476 with two screws would double the number of attachment steps but eliminate the rotation issue. In this embodiment, a PCB is appropriately used so that the interface board provides an electrical connection to the protrusion 470. Further modifications are conceivable, such as providing the bottom plate above one of the facets 474, so that when bent, the bottom is duplicated and thus adds rigidity and consistency at the expense of material weight and cost disadvantages.

[0097] Referring to Figure 53, another illustrative faceted conductive tapered projection 480 is shown in the lower part of Figure 53, and a corresponding single-piece cutout 482 is shown in the upper part of Figure 53. This embodiment is similar to those in Figures 50 and 51 and includes four facets 454 with a tab 458, but the vertex facet 456 is omitted so that the four (side) facets reach a certain point. It should also be noted that further variations are conceivable, such as replacing the vertex facet 456 in the embodiments of Figures 50 and 51 with a rounded vertex formed by, for example, a retraction action. With respect to the tab 458 in the embodiments of Figures 50 and 51 and 53, the tab 458 is bent so that it abuts the interface substrate 460 at a 90-degree angle when the projection 480 is bent into its final shape (for example, as at the bottom in Figures 51 and 53). Tabs 458 can be soldered to the electrical traces of the interface board 460 when the interface board 460 is a printed circuit board (PCB). This allows for strong mechanical and electrical connections of the conductive tapered projections 450, 480 to the interface board 460. Alternatively, tabs 458 can pass through the interface board and be attached to the vertical board below. Optionally, neighboring edges of facets 454 can be joined using soldering or a tab and receptacle array (not shown). This method improves upon the flat-bottom version by reducing weight and not requiring any mechanical connections to the PCB other than the tab joining. The use of tabs 458 reduces assembly time and overall system size, weight, and cost (SWAP-C) compared to an approach using a bottom plate 476, such as in the embodiment of Figure 52.

[0098] Referring to Figure 54, another illustrative faceted conductive tapered projection 490 is shown in the lower part of Figure 53, and a corresponding single-piece cutout 492 is shown in the upper part of Figure 53. This embodiment employs four facets 494, each accompanied by a tab 498 positioned offset at the corner of the facet 494. Here, the interface substrate 460 has a thickness of at least the depth of the triangular facets 494 added to the tab. The illustrative tab 498 is offset to one side, but it could alternatively be central with triangles added to both sides.

[0099] Referring to Figure 55, an embodiment is disclosed that employs a plate with a concave (i.e., external) support. The DSA may include a radome (i.e., a structural enclosure that may optionally be weather-resistant) for protecting the conductive tapered projection and providing a safe surface for external contact. In this embodiment, the radome 500 includes or defines a form 502 with a recess 504 in the shape of the tapered projection. To construct the conductive tapered projection 506, a sheet of metal is laid on the form 502 (for example, at the position graphically indicated by the dashed line 508 in Figure 55), and then punching is applied to press the sheet metal into the recess 504 in the shape of the tapered projection. Alternatively, a separate sheet may be punched to form each projection 506. The punching may be formed within the same cross-section as the projection 506. (In Figure 55, a gap is shown between the surfaces of the recess 504 and projection 506 of the tapered projection shape to distinguish them; however, it should be noted that in actual fabrication, the tapered projection 506 will be compressed against and in contact with the corresponding surface of the recess 504 of the tapered projection shape.) This approach has certain advantages. It facilitates the automation of DSA assembly. It also provides support for the projection 506, thereby enabling thinner materials and a higher level of environmental robustness. The radome 500 should be made from a dielectric material such as plastic and can be fabricated by manufacturing approaches such as injection molding or three-dimensional (3D) printing technology. Injection molding can construct a strong, lightweight, and low-cost radome. It should be noted that the form 502 does not need to be solid and can instead be mostly hollow.

[0100] The following describes several further illustrative implementations that address the recognized challenge in this specification, namely that the interface substrate being metal (e.g., a PCB with a ground surface) can adversely affect the RF performance of the DSA.

[0101] The DSA architecture operates best when there is no conductive material immediately behind the gap between the conductive tapered projections. On the other hand, most radio frequency components perform best when mounted in close proximity to a ground surface, for example, on a PCB with a ground surface. To address this issue, some embodiments disclosed herein employ a PCB mounted perpendicular to the surface on which the projections are mounted.

[0102] In DSA designs such as that shown in Figure 2, the protrusion 20 is mounted directly onto a printed circuit board (PCB) 10, and the opposing side of the PCB 10 is used to mount an RF component (e.g., the chip balun 30 in the embodiment of Figure 2). The PCB 10 has at least two layers, with a conductive trace connecting the “upper” protrusion 20 to the balun 30, and either the inner layer (if there are more than two layers) or the outer layer has a water-immersion ground surface. The water-immersion ground surface provides a low-resistance surface for electrical flow by filling the surface with conductive material as much as possible. The ground surface is included to improve the performance of the RF component.

[0103] Referring to Figure 56, this is schematically illustrated by showing the conductive tapered projection 20 and the underlying grounding surface 510 (which is part of the PCB 10 in the embodiment of Figure 2). The grounding surface 510, which is integrated with the same substrate (i.e., PCB 10) on which the projection 20 is mounted, results in a conductive surface mounted less than one full wavelength away from the gap between the projections 20 at the base of the projection 20. Figure 56 schematically illustrates the resulting RF interference caused by the reflection of incident radio frequency waves returning into the projection space. The interference can be both constructive and destructive, but the overall consequences are a decrease in broadband performance and increased design complexity required to resolve such interference at multiple angles of arrival and frequencies.

[0104] One solution (not shown) is to replace the continuous grounding surface with a grounding surface that extends below the base of the projections but not between the projections. In such an approach, the RF components would be small enough so that they fit perfectly below the base of the projections. However, this approach would require a complex "grid-like" grounding surface and very small RF components.

[0105] Referring to Figure 57, another solution is illustrated. By moving the conductive surface, i.e., the grounding surface 510, further, and then, one wavelength away from the base of the projection 20, the PCB can be used in an orientation perpendicular to impacting electromagnetic waves (for example, as in Figure 2). This approach involves providing standoffs 520 from the projection 20 to the PCB, which provide rigid support, and conductive connections 522 for each face of the projection 20, for example, four connections 522 when the projection 20 is square or rectangular. In a variant embodiment (not shown), the conductive connections 522 provide rigid support so that separate standoffs 522 can be optionally excluded. The standoffs provide a gap 524 between the base of the projection 20 and the grounding surface 510. This approach is most suitable for higher RF operating frequencies because, over low frequencies, the required gap 524 is large, which can reduce rigidity and lead to failure under shock and vibration. For example, at 400 MHz, the spacing 524 provided by the standoffs would need to be approximately 0.75 meters. In contrast, at 10 GHz, the spacing 524 provided by the standoffs would only need to be 3 centimeters.

[0106] Referring to Figure 58, another solution is to mount the conductive tapered projections 20 on a non-conductive interface substrate 550 and the RF components 552 on a vertical printed circuit board (PCB) 560 oriented perpendicular to the interface substrate 550. That is, rather than mounting the projections 20 on an interface substrate which is a PCB with a conductive ground surface, in the embodiment of Figure 58, a dielectric substrate interface substrate 550 is used. The upper surface of the dielectric interface substrate 550 supports the projections 20, and a set of PCBs 560 for supporting the RF components 552 is oriented perpendicular to the surface 550. The vertical PCBs 560 contain or support the RF components 552 mounted across the ground surface of the PCBs 560. In one embodiment (shown in Figure 58), there are vertical PCBs 560 located between each row of projections 20. In another embodiment (not shown), there is one vertical PCB below each row of projections. Placing the vertical PCB 560 between the rows of protrusions 20 is highly suitable for operating the DSA in differential mode.

[0107] The interface board 550 can be manufactured from any rigid or semi-rigid dielectric material such as plastic (e.g., acrylonitrile butadiene styrene, i.e., ABS). Alternatively, the interface board 550 can be a printed circuit board (PCB) but without a continuous ground plane. Using a PCB without a ground plane but with conductive traces as the interface board 550 allows for easier connection of signals between the protrusions 20 to a connection with a vertical PCB 560 (which also lacks a ground plane). One approach is to employ card edge connectors for the connection to the vertical PCB 560. Using a PCB without a ground plane as the interface board 550 also allows for simplification of the design, as the edges are terminated with loads directly on the PCB. However, using a PCB without a ground plane as the interface board 550 increases costs compared to using a sheet of dielectric material. Sheet dielectrics can be fabricated to capture the vertical PCB via various fastening configurations such as screw holes, with corresponding right-angle brackets, edge connectors, tenons, etc. Another option is to create mounting sections for the projection 20, mounting sections and surfaces through screws, rivets, or equivalents, and mounting sections that are mechanically and electrically attached to the vertical PCB 560. The mounting sections may be soldered or compression-type, optionally assisted by screws.

[0108] In some embodiments, the interface board 550 forms part of the housing for the DSA, for example, the interface board 550 may be one side of a five-sided box enclosure. The front surface has projections and an optional radome, while the bottom surface has connection points for an optional rear cover (see Figures 64 and 65).

[0109] In some embodiments, the edge 560 of the vertical PCB is fixed to the interface substrate 550. In this arrangement, the vertical substrate 560 is subjected to stress when subjected to shock or vibration. These stresses can be mitigated by rigidly mounting the interface substrate 550 and / or by incorporating a second support substrate 562 oriented parallel to the interface substrate 550 so as to fix the edge of the vertical substrate 560 distal to the interface substrate 550, as shown in Figure 59. The second support substrate 562 should also not contain a contact surface unless the vertical substrate 560 is large enough to position the second support substrate 562 at a distance of more than one RF wavelength from the base of the projection 20.

[0110] Figure 60 shows a plan view of a DSA incorporating the concept described in Figure 58. Here, the upper surface of the interface board 550 is a PCB (without a grounding surface) that allows interconnection 564 of the vertical row boards 560 to the rows of projections 20 and optional edge terminations 566. The design in Figure 60 may also optionally include a second support board 562 (obscured from the view in Figure 60) which may improve the mechanical rigidity of the assembly to improve robustness against shock and vibration. If the second support board 562 is included, it may optionally include additional routing of electrical connections between the vertical row boards 560 to simplify connections to further signal chain elements. As previously stated, if the vertical boards 560 are large enough to position the second support board 562 at one or more RF wavelengths away from the base of the projections 20, the second support board 562 may also include a grounding surface and RF components.

[0111] Referring to Figures 61-63, in another embodiment, two orthogonal sets of vertical boards 560, 570 are provided. Set 560 of vertical boards (also referred to as “row boards”) is perpendicular to the interface board 550, while another set 570 of vertical boards (also referred to as “column boards”) is perpendicular to the interface board 550 and also perpendicular to the row boards 560. In this embodiment, the row boards 560 and column boards 570 include cutouts 572, allowing the row boards and column boards 560, 570 to interlock and form a two-dimensional grid of vertical boards 560, 570, all of which are perpendicular to the interface board 550. This facilitates providing electrical connections to both the row and column of the projection 20, and the grid of interlocking row and column boards 560, 570 provides additional rigidity to the assembly. The cutout 572 allows the intersecting row and column PCBs 560, 570 to intersect and interlock with each other. If the cutout 572 is mechanically attached (e.g., by adhesive) or has a tight fit when assembled, the assembly becomes a self-supporting two-dimensional grid. Although not shown in Figures 61-63, a second support board 562 in the embodiment of Figure 59 is also included and can further improve rigidity. The benefit of this method using intersecting row and column vertical boards 560, 570 is that it simplifies the electrical connections of the projection 20 to both rows and columns, improves the rigidity of the assembly, and optionally allows for the omission of the second support board 562 (due to the improved rigidity provided by the interlocking row and column boards 560, 570). Again, the interface board 550 can be made from any non-conductive material or can be a PCB without immersion filling (i.e., without a continuous grounding surface). However, the use of both column and row boards 560 and 570 alleviates the need for conductors on the interface board 550, and thus allows the interface board 550 to be a simple dielectric board without a printed circuit network.

[0112] Referring to Figures 64 and 65, a complete DSA assembly, including the embodiment shown in Figures 61-63, is shown. Figure 64 shows an exploded perspective view of the DSA assembly. This embodiment does not include the second support substrate 562. In the DSA assembly of Figure 64, the interface substrate 550 is the surface of a five-sided housing or enclosure 580, shown separately in Figure 65. The projection 20 is positioned on a separate mounting section 320, which is fastened by screws 306 (as previously illustrated and described in Figure 36). The mounting section 320 is shown in Figure 34. The DSA assembly of Figure 64 further includes a radome 582 with associated gaskets 584. The radome 582 is fitted across the conductive tapered projection 20 and across part or all of the enclosure or housing 580 and is fastened by fasteners 586. On the rear side of the enclosure or housing 580, a rear cover or support 588 and associated gasket 590 are provided and secured to the DSA assembly by fasteners 592. The design also utilizes the interface substrate 550 as a dielectric surface that forms the surface of the five sized housings 580 (see also Figure 65). The housings 580 include grooves on their inner surfaces (not shown) that reinforce the edges of the vertical substrates 560, 570, thereby improving shock and vibration survivability. The interface substrate 550 (optionally, the entire housing 580) may be a single-piece plastic component, for example, manufactured by additive manufacturing or injection molding. As described, the projection 20 connects to individual mounting sections 320, which then mechanically and electrically adhere to the row and column substrates 560, 570. The mounting sections 320 can be made from stamped metal, which significantly reduces the material and manufacturing costs of the projection 20.

[0113] The DSA designs disclosed herein can be employed with a wide range of RF component configurations. Several illustrative signal chains that are appropriately used in conjunction with the disclosed DSAs are presented below.

[0114] A DSA interfaces with free space for electromagnetic capture and / or activation in different modes (depending on the application), which means that it gradually reduces the difference between RF signals between two points. Most commercially available RF networks exhibit a single-ended mode of operation, where the signal is on a single conductor and references ground. DSA architectures can be fabricated to work with single-ended networks through a converter called a balun (i.e., "balanced / unbalanced"). This is illustrated in Figure 66, which shows a side view (top view) and a top view (bottom view). Figure 66 shows RF coupling, where a balun 600 connects a conductive tapered projection 20 and converts the differential signal to a single-ended signal. Figure 66 shows a 3×2 DSA configuration (which can extend up to any M×N DSA configuration (where M and N are integers greater than or equal to 1)). In this case, the conductive tapered projection 20 is a four-faceted pyramid, and each facet is connected to an opposing facet of a neighboring projection 20 through the differential side of the balun 600. In this specification, this space is referred to as a pixel.

[0115] Generally, the balun is connected in some form to a signal chain, and two specific embodiments are shown in Figure 67. The embodiment in Figure 67 relates to a transceiver, i.e., a DSA that provides both transmission (TX) and reception (RX) operations. If a DSA that provides only a transmitter, i.e., only transmission (TX) operation, or only a receiver, i.e., only reception (RX) operation, is desired, the switch 614 (upper time-division duplexed signal chain 610) or the circulator or duplexer 616 (lower frequency-division duplexed or fully duplexed signal chain 612) can be omitted, and paths that are not needed (TX or RX) can also be omitted. Figure 67 also shows the direct attachment of the signal chains 610, 612 to the balun 600, with an equal one-to-one ratio between the number of protrusions 20 and the number of opposing faces of the signal chains.

[0116] The upper portion of Figure 67 shows an embodiment of a signal chain 610 using an RX / TX switch 614. The design of the signal chain 610 does not directly power the receiving circuit with the transmission circuit. The switch 614 serves to isolate the TX and RX paths. Circuit 610 often cannot perform both transmission and reception simultaneously, a function known as time-domain duplexing (TDD). However, the electrical architecture of a DSA may have several signal chains 610 operating in RX mode and several signal chains operating in TX mode simultaneously, providing both transmission and reception operations at the same time, even with reduced aperture efficiency. The use of the switch 614 within the signal chain 610 has the advantages that the switch is low-cost, readily available, can handle high power, and can operate over a wide bandwidth.

[0117] The lower portion of Figure 67 shows an embodiment of a signal chain 612 that can operate in either frequency division duplexing (FDD) or full duplexing (FD). FDD allows simultaneous transmission and reception by transmitting and receiving on separate frequencies and filtering out the transmission frequency from the received signal. Here, switch 614 is replaced by component 616 such as a diplexer or circulator. The diplexer divides transmission and reception by frequency, while the circulator acts like a series of gates, allowing transmission energy to avoid reflections, primarily into the RX path. The diplexer is not adjustable and requires an internal design approach to frequency operation (e.g., specified transmission and reception frequencies or frequency band). Typical commercially available circulators do not exceed approximately 1 GHz (or 1 octave) within the bandwidth. This imposes constraints on DSA when using signal chains such as the illustrative signal chain 612. FD means that the isolation of the RX path from the TX path can be maintained while the signal chain operates simultaneously on the same frequency in both transmission and reception modes. This is generally achieved through the use of different antennas or circulators, combined with a cancellation network, which connects the TX path to the RX path through inverse signals. The DSA architecture has the TX path and the RX path on different sets of projections 20, and therefore full duplex operation can be achieved by using different signal chains for each mode, or by including circulators.

[0118] In TDD mode, FDD mode, or FD mode, the signal chain is varied and can support a number of different electrical architectures, each with its own SWAP-C / performance trade-offs.

[0119] Referring to Figure 68, an illustrative 4x4 DSA supports up to 40 individual signal chains, which are graphically represented by circles 620 in Figure 68. Benefits of this approach include a lower noise floor due to the averaged uncorrelated noise of low-power TX amplifiers (often called power amplifiers, PAs) and RX amplifiers (often called low-noise amplifiers, LNAs), an increased signal dynamic range, sub-aggregation of apertures where some parts of the aperture are dedicated to one function and different parts to different functions, and the ability to use dynamic and arbitrary beamforming and polarization generation. However, in SWAP-C, this performance becomes a disadvantage because each signal chain consumes space and power, increasing costs.

[0120] Referring to Figure 69, it is therefore desirable, at times, to combine signals so that one signal chain supports multiple pixels. One way to do this is to combine pixels in rows and columns, which maintains multiple polarization operations and beam steering and formation in orientation and height. To combine pixels, couplers or splitters (e.g., coupler 632 or coupler 634 in the illustrative signal chain 630 in Figure 69) are inserted into the signal chain at one or more locations in the TX / RX path. Couplers 632, 634 are bidirectional devices, meaning that current can flow in either direction or both directions simultaneously. Figure 69 shows that coupler 632 may be placed between the duplexer and the balun, or alternatively, coupler 634 may be placed upstream of the power amplifier (PA) 636 in the TX path and downstream of the low-noise amplifier (LNA) 638 in the RX path. (Figure 69 shows a coupler 632 coupled to a single illustrative pixel via an illustrated balun 600, but more generally, coupler 632 can be coupled to multiple pixels via individual baluns of the pixels. Similarly, illustrative coupler 634 is coupled to a single illustrative pixel via the power amplifier 636 and low-noise amplifier 638 of the illustrative pixel, but more generally, coupler 634 can be coupled to multiple pixels via individual components 634, 636 of the pixels.) The first location (i.e., coupler 632) is less expensive because one coupler 632 is used for both the TX and RX paths, however, this arrangement suffers a performance disadvantage because coupler 632 typically has limited power handling capacity and introduces signal attenuation (loss) in the RX path. The second location (i.e., coupler 634) doubles the number of couplers required, but the thermal noise per pixel is uncorrelated and the system noise is

number

[0121] The signal chain 630 in Figure 69 assumes that a sufficient number of signal chains exist to perform beam steering and beamforming as desired. While some beamforming and steering can be performed using two signal chains, four signal chains provide a better performance solution. The highest cost and highest power consumption portion of the signal chain is often the analog-to-digital conversion and digital signal processing required to perform the operations necessary for beam steering and beamforming.

[0122] Referring to Figure 70, signal chain 640 illustrates one method for reducing system cost. Signal chain 640 includes a phase shifter or time delay 642 downstream of the digital-to-analog converter (DAC) 644 and a phase shifter or time delay 646 upstream of the analog-to-digital converter (ADC) 648. This method reduces the number of signal chains required, and in some cases, only one signal chain is needed. The trade-off is that the time shifters or delays 642 and 646 may limit wideband operation in some implementations.

[0123] It should be noted that in all signal chains described herein, a digital-to-analog converter may be followed by a mixer that increases the signal frequency as desired, and an analog-to-digital converter may be preceded by a mixer that decreases the signal frequency as desired.

[0124] Referring to Figure 71, several RF components can operate differentially on the signal instead of single-ended. Using such “differential” RF components allows the DSA to operate with a complete differential signal chain 650, as shown in Figure 71, where the input is maintained as a balanced pair all the way from the digital word in the ADC 648 or DAC 644, or up to the conversion therefor. The power amplifier (PA) 636 and low-noise amplifier (LNA) 638 process the differential signal in this embodiment. The illustrative embodiment in Figure 71 further includes a switch (or, alternatively, a duplexer or circulator) 652 to provide time-division or frequency-division duplexing of the TX and RX differential paths, as well as an optional filter 654 upstream of the LNA 638. Note that the switch, duplexer, or circulator is coupled to one or more aperture pixels without an intervening balun.

[0125] One variant embodiment may employ a semi-differential signal chain (not shown) in which the differential signal is maintained at a short distance between the DAC and ADC, and a balun is used to convert it at that point.

[0126] Each coupler inserts a loss, limiting the number of channels and increasing SWAP-C. Various designs can be employed to mitigate these effects.

[0127] Referring to Figure 72, one embodiment is shown in which the coupler 632 is included after the signal chain 660 (for example, this could be the signal chain 630 in Figure 69 or the signal chain 640 in Figure 70) and extends to four pixels. These pixels are shown in columns, and the coupler 632 is a 4-1 coupler utilized in front of the signal chain 660. In this embodiment, all four pixels receive the same signal, and pixel-level steering along the direction is not possible. An optional modification is to place a phase shifter between the coupler and the balun. This approach represents a low-power, low-cost configuration. Note that these embodiments can be easily extended to larger DSAs, e.g., 10x10 couplers requiring 9-1 couplers.

[0128] Figure 73 shows one embodiment of how a coupler 632 may be constructed using multiple couplers 634 in series to generate a coupler with a larger spread or to allow phase shifts across multiple pixels. Figure 73 shows two 2-1 couplers 634 stacked in series. This may be chosen due to the SWAP-C or performance characteristics of 2-1 couplers versus 4-1 couplers, or due to the unavailability of the required coupler spread. Another reason may be that it is easier to make the total trace lengths from one pixel to another equal so as not to induce unequal time delays on the signal lines. In addition, mixers may be installed between the couplers 634 to allow for some beamforming and steering between groups.

[0129] Figure 74 illustrates that the coupler approach does not need to be homogeneous, i.e., the use of couplers is not balanced across pixels. In the embodiment of Figure 74, a 3-1 coupler 672 connects three pixels to the first signal chain 670, while the fourth pixel has a linear connection to the second signal chain 680. This approach may be useful when the DSA is designed to process multiple signals of interest simultaneously, with different power / sensitivity needs. In this case, the two signal chains 670 and 680 are combined in the digital domain when full DSA performance is required.

[0130] FIG. 75 shows yet another non-limiting illustrative embodiment, which improves performance by separating the TX path and the RX path from the aperture via a duplexer 690 (which can be a switch, circulator, diplexer, etc.). As shown in FIG. 75, the TX signal chain 700 feeds into a first 4-1 coupler 702, drives a power amplifier (Pa) 704, and transmits through the pixels of the DSA. The RX signal chain 710 receives the signal via a second 4-1 coupler 712 after amplification by a low noise amplifier (LNA) 714 (which may optionally contain a pre-filter). Here, doubling the number of couplers is necessary, but the performance is thereby improved. The LNA 714 can nullify the loss of the coupler, and since the Pa 704 is downstream, it is no longer limited by the power limit of the coupler.

[0131] FIGS. 76 - 81 present several further embodiments with various performance / SWAP-C trade space positions. Note that in these embodiments, the coupler 632 of FIG. 69, which interfaces directly with the balun 600, is used. Note that all of these embodiments can alternatively be implemented with the coupler 634 at the second position of FIG. 69.

[0132] FIG. 76 shows a 5×5 pixel DSA embodiment that results in four signal chains in horizontal polarization and four signal chains in vertical polarization using couplers 632 that are all 5-1 couplers. This configuration pairs well with a software-defined radio (SDR) that has a number of channels that is a power of 2 (i.e., 2 n )), e.g., 2 3 = 8 channels, which is commercially available. This design enables simultaneous operation on both polarizations, the ability to measure the incident polarization, and the ability to beam steer and form in both azimuth and elevation. A disadvantage of this design in the context of an illustrative 5×5 pixel DSA is that it employs 5-1 couplers, which are not a common spread.

[0133] Referring to Figure 77, in the context of an illustrative 5x5 pixel DSA, to mitigate the need for an uncommon 5-1 coupler, the design of Figure 77 can be adopted, in which pixels on one vertical and one horizontal perimeter are not brought into the signal chain, resulting in a slight reduction in the effective aperture area. Thus, only one face of the projection 20 is in use. Here, all couplers 632 are 4-1 couplers. This approach allows for the use of a more common 4x1 coupler spread, as powers of 2 are most commonly used. To make better use of the unused faces, the approach of Figure 74 may be applied, allowing for the investigation of additional signals of interest.

[0134] The approach in Figure 78 is useful when a single polarization is of interest, or when beam steering and shaping are required for only one polarization. Here, the rows are connected by a coupler 632, provided by four signal chains 630, as already described with reference to Figure 76. However, in the embodiment of Figure 78, the columns are combined into a single signal chain 720 by a 4-1 coupler 722 that extends to four 5-1 couplers 724. This configuration is useful, for example, when two signals of interest are operating and shaping and steering are not required for one of those signals.

[0135] Figure 79 shows a DSA architecture that provides a single chain 730 without the capability to measure or control polarization or beamforming / direction. The single signal chain is coupled in rows and columns by 2-1 couplers 731, each of which extends to four 5-1 couplers 734, and then to two 4-1 couplers 732. This architecture is useful, for example, to support existing single-channel radios that require efficient ultra-wideband performance.

[0136] Figure 80 shows a DSA in which each pixel has its combined horizontal and vertical polarizations and is connected to its own signal chain. This approach is useful when low noise and high power efficiency are required, and robust beamforming is necessary, as the beam pattern and reception pattern are symmetrical in polarization.

[0137] Referring to Figure 81, one benefit of DSA is its ultra-wide bandwidth and ability to support many signals simultaneously. However, a given DSA implementation may be limited by the bandwidth of the data converter. To mitigate this limitation, the architecture of Figure 81 can be used in any of the embodiments described above. As shown in Figure 81, after pixels are combined into rows, columns, or some other configuration, they are then divided into multiple converters. Across the transmission (TX) path, multiple DAC converters 750 are coupled to a power amplifier (PA) 754 via a coupler 752. Across the reception (RX) path, multiple ADC converters 760 are coupled to a low-noise amplifier (LNA) 764 via a coupler 762, optionally with a pre-filter 766. Note that the converters may include appropriate filters and mixers. This architecture is suitable, for example, to reduce the effects of losses in the coupler when LNAs and PAs are present.

[0138] Preferred embodiments are illustrated and described. Naturally, modifications and alterations will be conceivable to those skilled in the art, provided they carefully read and understand the preceding detailed description. It is intended that the present invention includes all such modifications and alterations to the extent that they fall within the scope of the appended claims or their equivalents.

Claims

1. A radio frequency (RF) aperture, An interface substrate having a front side and a back side, and including a contact surface, An array of conductive protrusions, wherein each conductive protrusion is tapered so as to move away from the front side of the interface substrate to its apex or tip, and each conductive protrusion is supported on the interface substrate by conductive connections that position the conductive protrusions away from the front side of the interface substrate; An RF network disposed on the back side of the interface board and electrically connected to a differential RF receiver and / or transmission element defined by neighboring pairs of conductive protrusions, wherein the RF network is electrically connected to the differential RF receiver and / or transmission element by conductive connections that support the conductive protrusions on the interface board and position the conductive protrusions away from the front side of the interface board. An RF aperture equipped with this.

2. The RF opening according to claim 1, wherein each conductive protrusion is separated from the front side of the interface substrate by four conductive connections that support the conductive protrusion on the interface substrate and position the conductive protrusion so as to be away from the front side of the interface substrate.

3. Each conductive projection has quadruple rotational symmetry, or The RF opening according to claim 1, wherein each conductive projection is provided with a cutout in the sheet metal.

4. The RF aperture according to claim 1, further comprising a radome that fits across the conductive protrusion.

5. The RF aperture according to claim 1, wherein the RF network is arranged on the back side of the interface board, and the RF network is arranged on two or more printed circuit boards arranged parallel to the interface board.

6. The RF network includes an analog-to-digital converter and a digital signal processing (DSP) network, or The RF aperture according to claim 1, wherein the RF network includes a digital-to-analog converter.

7. The RF network is Performing RF reception in one or more received signal chains operating in receive mode using the receiving subset of the conductive protrusions, Performing RF transmission in one or more transmission signal chains operating in transmission mode using the transmission subset of the conductive protrusions, It is to operate as desired, simultaneously in the receiving mode and the transmission mode. The RF aperture according to claim 1, configured to perform the following:

8. The RF aperture according to any one of claims 1 to 7, further comprising at least two printed circuit boards arranged on the back side of the interface board, wherein the interface board and the at least two printed circuit boards are parallel to each other.

9. A radio frequency (RF) aperture, An interface board having a front side and a back side, An array of conductive protrusions, each conductive protrusion being tapered so as to move away from the front side of the interface substrate to its apex or tip, and each conductive protrusion being supported on the interface substrate, An RF circuit network is arranged on the back side of the interface board and electrically connected to a differential RF receiving and / or transmission element defined by a neighboring pair of conductive protrusions. Equipped with, The RF network is Performing RF reception in one or more received signal chains operating in receive mode using the receiving subset of the conductive protrusions, The RF transmission is performed in one or more transmission signal chains operating in transmission mode using the transmission subset of the conductive protrusions. An RF aperture configured to perform the following actions.

10. The RF aperture according to claim 9, wherein the RF network is configured to operate the RF aperture in both the receiving mode and the transmission mode simultaneously.

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