MULTIPORT ANTENNA, MULTIPORT ANTENNA SYSTEM, AND METHODS OF OPERATION

A system comprising an electronic system comprising a plurality of solid state radio frequency (RF) amplifiers and an antenna structure. The antenna structure includes a dielectric substrate and a plurality of antenna elements extending along the dielectric substrate. The antenna structure further includes a plurality of feedlines each of which is coupled to an individual antenna element of the plurality of antenna elements. An output of each of the plurality of solid state RF amplifiers is coupled an individual feedline of the plurality of feedlines.

TECHNICAL FIELD

The present disclosure relates to antennas, systems including antennas, and methods of operation thereof.

BACKGROUND

Generation of high-power radio frequency electromagnetic radiation is becoming increasingly valuable in communications and other applications. However, increasing the power of electromagnetic radiation emitted by antennas can result in a difficult balance of design considerations. One conventional approach, binary tree combining, involves combining signals using power couplers in one or more stages and outputting the combined signals via a single antenna element. Besides increasing size and weight of the system, each stage of power combining results in loss of overall signal strength. Moreover, some conventional approaches sacrifice system agility in certain domains, such as phased arrays.

SUMMARY

Disclosed herein are novel aspects of antenna structures, electronic systems coupled thereto, and phased array systems. Systems disclosed herein can include an electronic system comprising a plurality of solid state radio frequency (RF) amplifiers; an antenna structure including a dielectric substrate, a plurality of antenna elements extending along the dielectric substrate, and a plurality of feedlines each of which is coupled to an individual antenna element of the plurality of antenna elements wherein an output of each of the plurality of solid state RF amplifiers is coupled an individual feedline of the plurality of feedlines.

The plurality of antenna elements can include a first pair of antenna elements extending in opposite first directions, and a second pair of antenna elements extending in opposite second directions, the second pair of antenna elements being arranged transversely to the first pair of antenna elements. The plurality of antenna elements can be bowtie antenna elements. The antenna structure can include a planar antenna element on a first side of the dielectric substrate, and a ground plane on a second side of the dielectric substrate opposite to the first side, the first pair of antenna elements and the second pair of antenna elements being located within the dielectric substrate between the planar antenna element and the ground plane.

The electronic system can be configured to receive a radio frequency (RF) signal; split the RF signal into a plurality of RF signals; and phase shift a subset of RF signals of the plurality of RF signals, wherein the solid state RF amplifiers amplify the plurality of RF signals.

The electronic system can include a phase shifter configured to selectively transition between a first state and a second state, the first state corresponding to a first polarization of high-power microwaves emitted by the antenna structure, and the second state corresponding to a second polarization of high-power microwaves emitted by the antenna structure. The phase shifter can be configured to selectively transition between a third state and a fourth state, the third state corresponding to a third polarization of high-power microwaves emitted by the antenna structure, and the fourth state corresponding to a fourth polarization of high-power microwaves emitted by the antenna structure.

Implementations of the present disclosure include systems can include an electronic system configured to receive an RF signal, the electronic system including a first hybrid coupler that splits the RF signal into a first signal and a second signal, the second signal phase-shifted relative to the first signal; a first set of transmission paths including a second hybrid coupler and a first set of RF amplifiers of a plurality of RF amplifiers; and a second set of transmission paths including a third hybrid coupler, a first phase shifter, and a second set of RF amplifiers of the plurality of RF amplifiers; and an antenna structure including a plurality of antenna elements each coupled to an output of one of the plurality of RF amplifiers. The first signal can be conveyed through the first set of transmission paths and the second signal is conveyed through the second set of transmission paths.

The first phase shifter can be connected between the first hybrid coupler and the third hybrid coupler. The first phase shifter can be connected between the third hybrid coupler and an RF amplifier of the second set of RF amplifiers. The first set of transmission paths can include a second phase shifter.

The second phase shifter can be connected between the second hybrid coupler and a first RF amplifier of the first set of RF amplifiers, and the first phase shifter is connected between the third hybrid coupler and a second RF amplifier of the second set of RF amplifiers. The first phase shifter and the second phase shifter can each be configured to transition between a plurality of phase shift states, each phase shift state corresponding to a different polarization of high-power microwaves emitted by the antenna structure. The first hybrid coupler can be a different type of hybrid coupler than the second hybrid coupler and the third hybrid coupler. The plurality of antenna elements can include a first pair of antenna elements extending in opposite first directions; and a second pair of antenna elements extending in opposite second directions, the second pair of antenna elements arranged transversely to the first pair of antenna elements.

Embodiments of the present disclosure include phased array systems that can include an RF signal generator configured to generate a first plurality of RF signals; a plurality of electronic systems each coupled to the RF signal generator to receive an RF signal of the first plurality of RF signals and each configured to emit a plurality of amplified RF signals, each of the plurality of electronic systems including a phase shifter configured to selectively transition between a plurality of states; an antenna array including a plurality of antenna structures coupled to outputs of the plurality of electronic systems; and a control system including one or more processors and memory storing instructions that, as a result of execution by the one or more processors, cause the control system to determine a set of waveform parameters including a selected polarization of an RF beam to be formed, and control the phase shifters of the electronic systems to cause the antenna structures to emit the RF beam having the selected polarization.

Execution of the instructions by the one or more processors can cause the control system to determine an elevation of the RF beam to be formed and an azimuth of the RF beam to be formed, and control the RF signal generator to adjust relative phases of the first plurality of RF signals according to the azimuth and elevation.

Each antenna structure can include a plurality of antenna elements that includes a first pair of antenna elements extending in opposite first directions; a second pair of antenna elements extending in opposite second directions, the second pair of antenna elements arranged transversely to the first pair of antenna elements; and a plurality of feedlines each coupled to one of the plurality of antenna elements.

The phase shifters can be two-state phase shifters that transition between a first state in which an output of the phase shifter is not phase shifted and a second state in which the output of the phase shifter is phase shifted by 180°. The phase shifters can be four-state phase shifters that transition between a plurality of states including a first state in which an output of the phase shifter is not phase shifted, a second state in which the output of the phase shifter is phase shifted by 90°, a third state in which the output of the phase shifter is phase shifted by 180°, and a fourth state in which the output of the phase shifter is phase shifted by 270°.

DETAILED DESCRIPTION

The present disclosure provides examples of antennas, radio frequency systems, and methods. More specifically, the present disclosure provides multiport antenna structures to combine a plurality of RF signals. The present disclosure also enables selective polarization of high-power microwaves emitted by a multiport antenna structure.

The term “set,” as used herein (e.g., a set of keys), refers to a non-empty collection of members. The phrase “coupled to,” as used herein and unless otherwise indicated by the context of the usage, means that a first circuit element is coupled to a second circuit element, with or without intervening elements therebetween. The term “subset,” as used herein, refers to a proper subset unless otherwise indicated.

FIG.1illustrates a top perspective view of a multiport antenna structure100according to one or more embodiments. The antenna structure100includes a plurality of antenna elements102-1,102-2,102-3, and102-4(collectively “antenna elements102”) arranged about an axis Z extending through a center of the antenna structure100. Each of the antenna elements102is comprised of an electrically conductive material, such as aluminum, copper, gold, or an alloy thereof. The antenna elements102are spaced apart from each other in a circumferential direction of the antenna structure100. The antenna elements102are also electrically isolated from each other on the antenna structure100. The antenna structure100is a high-power microwave antenna in at least some embodiments.

Each of the antenna elements102has a triangular shape with a vertex of the triangular shape provided adjacent to the axis Z. Opposite pairs of the antenna elements102may be positioned in a bowtie configuration. For instance, as shown, the antenna elements102-1and102-3are positioned in a first bowtie configuration and the antenna elements102-2and102-4are positioned in a second bowtie configuration arranged transverse to the first bowtie configuration. In some embodiments, the triangular shapes are isosceles triangle shapes with a base of the isosceles triangle shape located distally relative to the center of the arrangement of antenna elements102. In some embodiments, the triangular shapes are equilateral triangle shapes or right triangle shapes.

The antenna elements102may have a shape other than triangular in some embodiments. By way of non-limiting example, the antenna elements102may have a circular shape with a peripheral edge adjacent to the axis Z. In some embodiments, the circular shape may be an elliptical shape having a major axis extending in a radial direction R. As another non-limiting example, the antenna elements102may have a rectangular shape with a length extending in the radial direction R. The antenna elements102may have a quadrilateral shape in some embodiments.

Each of the antenna elements102has an electrical connection104to a conductor that conveys a radio frequency signal. The antenna elements102are provided on a surface of or embedded within a substrate106. The substrate106is a dielectric or electrically insulating material, such as a polymer (e.g., resin, polyimide), silicon, or ceramics, by way of non-limiting example. The substrate106has a circular shape in the antenna structure100; however, the substrate106may have other shapes (e.g., rectangular) without departing from the scope of the present disclosure. In some embodiments, the substrate106may include a plurality of the antenna elements102. The antenna structure100includes a housing108to which the substrate106is attached. The housing108has a cylindrical shape extending along the Z axis direction; however, the housing108may have a different shape without departing from the scope of the present disclosure. The housing108may contain electrical components and/or electrical systems in some embodiments.

FIG.2illustrates a bottom perspective view of the antenna structure100according to one or more embodiments. In the bottom perspective view of the antenna structure100, the housing108is removed for visibility and discussion purposes. The antenna structure100includes a plurality of feed lines110each connected to one of the antenna elements102. Each feed line110includes a conductor112terminating at one of the connections104(seeFIG.1). The feed lines110, in some embodiments, are coaxial cables including a dielectric insulator surrounding the conductors112and a shielding layer covering the dielectric insulator. Providing an RF signal input to each of the antenna elements102enables greater control of high-power microwave polarization and also enables greater power output relative to antenna structures with fewer signal inputs. In operation, the four feedlines110are equally excited in terms of RF signal amplitude.

FIG.3shows a top view of the antenna structure100according to one or more embodiments. In some embodiments, the antenna structure100includes a conductor114extending along a surface of one or more of the antenna elements102. Each conductor114extends from the connection104in a radial or outward direction relative to the center of the antenna structure100. Each conductor114may be mechanically and electrically coupled to the antenna elements102via solder, electrically conductive paste, or electrically conductive epoxy, by way of non-limiting example. The conductors114may increase current flow through the antenna element102to which they are coupled.

FIG.4illustrates a cross-sectional view of the antenna structure taken along the through line A-A inFIG.3according to one or more embodiments. As shown, the antenna elements102are located on an upper surface of the substrate106. The antenna elements102may be printed on the substrate106, e.g., via photolithographic techniques on the substrate106. The antenna structure100includes a conductive antenna ground plane116spaced apart from the substrate106at a distance D1. The distance D1, in some embodiments, is approximately k/4, where k is a wavelength of the electromagnetic radiation to be emitted from the antenna structure100.

The antenna structure100may include a guide118through which the feed lines110pass to couple to the antenna elements102. The guide118may include a conduit formed through a solid material, such as a plastic or polymer. The feed lines110terminate at one or more ports or connectors120, which are coupled to one or more electronic systems122described herein. The one or more ports120may be DIN connectors, MBX connectors, microcoaxial (MCX) connectors, QN connectors, or subminiature connectors (e.g., SMB, SMC, SMP), by way of non-limiting example. The antenna structure100may include a chassis124having an aperture through which the feed lines110extend to couple with the one or more electronic systems122.

FIG.5illustrates a top view of a multiport antenna structure500according to one or more embodiments. The antenna structure500is a high-power microwave patch antenna in some embodiments. The antenna structure500includes a patch502of planar conductive material positioned on a substrate504of dielectric material. The conductive material may be a metal, such as copper, aluminum, gold, or an alloy thereof, by way of non-limiting example.

The patch502has a symmetrical shape arranged around a central portion of the antenna structure500. The patch502has a square shape, as shown; however, the patch502may have a circular shape or a quadrilateral shape in some embodiments.

The antenna structure500also includes a plurality of microstrip lines506-1,506-2,506-3, and506-4(collectively “microstrip lines506) of planar conductive material. Each of the microstrip lines506has a first portion508that overlaps with the patch502in a thickness direction of the antenna structure500. Each of the microstrip lines506has a second portion510that does not overlap with the patch502in a thickness direction of the antenna structure500. A first set of the microstrip lines506(e.g., patches506-1,506-3) extend and are spaced apart from each other along a first direction of the antenna structure500(e.g., a width direction). A second set of the microstrip lines506(e.g., patches506-2,506-4) extend and are spaced apart from each other along a second direction of the antenna structure500(e.g., a length direction). The first set of the microstrip lines506is arranged transversely to the second set of the microstrip lines506.

FIG.6illustrates a cross-sectional view of the antenna structure500taken along the line B-B according to one or more embodiments. As shown, the microstrip lines506are spaced apart from the patch502in a thickness direction of the antenna structure500. A portion of the microstrip lines506overlap the patch502in the thickness direction of the antenna structure500. The microstrip lines506are capacitively coupled to the patch502to emit electromagnetic radiation from the antenna structure500.

The antenna structure500includes an antenna ground plane508provided on a bottom of the antenna structure500. The ground plane508is spaced apart from the patch502at a distance D2. The distance D2is approximately 0.1% of the wavelength k of the electromagnetic radiation to be emitted from the antenna structure500in some embodiments. The antenna structure500includes a plurality of feed lines510for conveying radio frequency (RF) signals to the microstrip lines506. Each pair of the feed lines510and the microstrip lines506collectively form L-shaped feed line for the antenna structure500. The antenna structure500includes a plurality of ports or connectors512for coupling the microstrip lines506to one or more electronic systems. A portion of the ports512may be electrically coupled to the ground plane508. The antenna structure500may include a layer514of dielectric material covering an upper surface of the patch502. In operation, the four feedlines510are equally excited in terms of RF signal amplitude received.

FIG.7illustrates a first simplified block diagram of an electronic system700according to one or more embodiments. The electronic system700is electrically coupled to an antenna structure701via one or more ports704. The antenna structure701may correspond to the antenna structure100or the antenna structure500respectively described herein. The electronic system700, in combination with the antenna structure701, enables selective emission of high-power microwaves having a selected polarization from among a plurality of polarizations. More particularly, the electronic system700may be controlled to generate high-power microwaves having a horizontal polarization, a vertical polarization, a left-hand circular polarization, and/or a right-hand circular polarization. The foregoing polarizations may be implemented with the antenna structure100having the orientation shown inFIG.3(relative to the horizon) or the antenna structure500being rotated 900 clockwise. For instance, the antenna element102-1corresponds to the antenna element702-1, the antenna element102-2corresponds to the antenna element702-2, and so on.

Advantageously, use of the antenna structures described herein also enables omission of power combiners in an RF system, the power combiners combining RF signals from a plurality of RF sources and feeding the combined RF signal are into a single port antenna. Instead, the systems described herein directly feed the RF signals from the plurality of RF sources into a corresponding one of the plurality of input ports of the multiport antenna and radiatively power combine the multiple signals at the output of the antenna. The multiport antenna is configured such that the active reflection at one of the plurality of input ports is minimized by destructively interfering the reflection at that input port with RF power coupled into that port from the remaining plurality of the input ports to reduce an amount of the active reflection at that port. The absence of additional power combining network eliminates size, weight, and loss restrictions.

The electronic system700includes an RF signal generator706, one or more driver amplifiers708, and a 90° hybrid coupler710. The RF signal generator706is configured to generate an RF signal712having a defined frequency. The one or more driver amplifiers708are configured to amplify the RF signal712to a desired level to generate an amplified RF signal714. The 90° hybrid coupler710receives the amplified RF signal714and outputs a first signal716from a first terminal and outputs a second signal718from a second terminal. The first signal716corresponds to the amplified RF signal714and the second signal718corresponds to the amplified RF signal714phase-shifted by 90°. The first signal716is conveyed through a first set of transmission paths717. The second signal718is conveyed through a second set of transmission paths719.

The electronic system700includes a 180° hybrid coupler720, an N-bit phase shifter722, and a 180° hybrid coupler724. The 180° hybrid coupler720outputs a third signal726corresponding to the first signal716and a fourth signal728corresponding to the first signal716phase-shifted by 180°. The N-bit phase shifter722phase shifts the second signal718by a variable amount to output a fifth signal730. The 180° hybrid coupler724outputs a sixth signal732corresponding to the fifth signal730and outputs a seventh signal734corresponding to the fifth signal730phase-shifted by 180°.

The electronic system700includes a controller736coupled to the N-bit phase shifter722and configured to control a state thereof. In some embodiments, the N-bit phase shifter722is a single bit phase shifter that may be controlled to transition the electronic system700between a horizontal polarization mode and a vertical polarization mode. In such embodiments, the two-state phase shifter722is controlled to emit the fifth signal730that is either phase-shifted by either 0° relative to the second signal718or by 180° relative to the second signal718.

In some embodiments, the N-bit phase shifter722is a two-bit phase shifter that may be controlled to transition the electronic system700between a horizontal polarization mode, a vertical polarization mode, a right-hand circular polarization mode, and a left-hand circular polarization mode. In such embodiments, the four-state phase shifter722is controlled to emit the fifth signal730that is phase-shifted by 0° relative to the second signal718, by 90° relative to the second signal718, by 180° relative to the second signal718, or by 270° relative to the second signal718. The two-bit phase shifter722may include first circuitry that is configured to selectively introduce a 1800 phase shift and second circuitry that is configured to introduce a 900 phase shift. The controller736may be a digitally controlled device configured to control the two-bit phase shifter722according to the following Table 1:

The controller736, in some embodiments, includes one or more hardware devices having circuitry that is hard-wired to perform as described herein (e.g., a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some embodiments, the controller736includes an electronic processing system (e.g., a general-purpose processor, a DSP, a central processing unit (CPU), a microcontroller, any combination thereof) and memory storing logic that, as a result of execution by the electronic processing system, causes the controller736to perform as described herein.

The electronic system700further includes a plurality of RF power amplifiers738-1,738-2,738-3,738-4(collectively “power amplifiers738”) that respectively amplify the third signal726, the fourth signal728, the sixth signal732, and the seventh signal734to a desired range. For instance, the power amplifiers738may amplify the RF signals by a desired ratio of input to output (e.g., ˜+20 dB). The power amplifiers738may be solid-state high power (e.g., 1000 W+) amplifiers that amplify RF signals in a desired frequency range. Input of the power amplifiers738may cause the power amplifiers738to operate in a desired class (e.g., Class A, Class AB). The power amplifiers738may include one or more wide bandgap semiconductor materials, such as Gallium Nitride or Silicon Carbide.

The power amplifiers738-1,738-2,738-3,738-4respectively generate amplified RF signals740-1,740-2,740-3,740-4. The amplified RF signals740-1,740-2,740-3,740-4are emitted by the antenna elements702-1,702-2,702-3, and702-4collectively via the antenna structure701as electromagnetic radiation having a selected polarization. The antenna structure701may be a single antenna structure among a plurality of antenna structures arranged in an array comprising one or more rows and/or one or more columns. For instance, a plurality of the antenna structures701and associated electronic systems700may be arranged in an N×N or M×N array, wherein N and M are integers equal to or greater than 1. The array of electronic systems700coupled to the array of antenna structures701may be collectively controlled to operate as a phased array. In some embodiments, the array of electronic systems700may include a single RF signal generator that generates and provides RF signals to the electronic systems700. During operation, the power amplifiers738emit amplified RF signals that are equal in RF signal amplitude. As a result, each of the antenna elements702is equally excited in terms of power received.

The first set of transmission paths717comprises a first transmission path including the power amplifier738-1and the antenna element702-1and comprises a second transmission path including the power amplifier738-2and the antenna element702-2. The second set of transmission paths719comprises a third transmission path including the power amplifier738-3and the antenna element702-3and comprises a fourth transmission path including the power amplifier738-4and the antenna element702-4.

In some embodiments, the electronic systems700may include a plurality of RF circulators742each coupled between outputs of the power amplifiers738and the antenna elements702. In some embodiments, the circulators742help to prevent or reduce inter-antenna element702active reflection due to mutual coupling and intra-element active reflection due to phase and/or magnitude imbalance between each of the ports704. The circulators742are three terminal devices that permit RF signals to travel and exit in a single direction between the terminals. One terminal of the circulators742is coupled to a high power (e.g., 500 W, 1000 W) termination node or component.

FIG.8illustrates a second simplified block diagram of an electronic system800according to one or more embodiments. Various features of the electronic system800are substantially similar to those described with respect to the electronic system700, so further description thereof is omitted for brevity. The electronic system800, in combination with an antenna structure801, enables selective emission of high-power microwaves having a selected polarization from among a plurality of polarizations. More particularly, the electronic system800and antenna structure801enable emission of high-power microwaves having either a vertical polarization or a horizontal polarization.

The electronic system800is coupled to an antenna structure801that is substantially similar to the antenna structure701. However, outputs of the electronic system800(e.g., from the RF power amplifiers) are coupled to different antenna elements of the antenna structure801relative to connection of the electronic system700to the antenna structure701.

The electronic system800includes an RF signal generator806having an output coupled to one or more driver amplifiers808, as described with respect to the electronic system700. The driver amplifier(s)808generate an amplified RF signal814is coupled to an input of a 1800 hybrid coupler810. The 180° hybrid coupler810outputs a first signal816that is conveyed along a first set of transmission paths817. The 180° hybrid coupler810outputs a second signal818that is conveyed along a second set of transmission paths819. The first signal816corresponds to the amplified RF signal814and the second signal816corresponds to the amplified RF signal814phase-shifted by 180°.

The first signal816is received by a 180° hybrid coupler820and the second signal818is received by a 180° hybrid coupler822. The 180° hybrid coupler820outputs a third signal824corresponding to the first signal816and outputs a fourth signal826corresponding to the first signal816phase-shifted by 180°. The 180° hybrid coupler822outputs a fifth signal828corresponding to the second signal818and outputs a sixth signal830corresponding to the second signal818phase-shifted by 180°.

The electronic system800includes a first two-state phase shifter832coupled to receive the fourth signal826. The electronic system800also includes a second two-state phase shifter834coupled to receive the sixth signal830. The first and second two-state phase shifters832and834are configured to operate in a first state in which an output thereof is not phase-shifted relative to an input. The first and second two-state phase shifters832and834are configured to operate in a second state in which an output thereof is phase-shifted relative to an input. In some embodiments, the first and second two-state phase shifters832and834, during operation in the second state, emit an output that is phase-shifted by 180° relative to the input.

The electronic system800further includes a controller836coupled to and configured to control states of the first and second two-state phase shifters832and834. In some embodiments, the controller836generates an output that collectively controls a state of the first and second two-state phase shifters832and834. In some embodiments, the controller836generates separate outputs that individually control states of the first and second two-state phase shifters832and834. An operational state of the two-state phase shifters832and834is controlled based on memory or registers thereof that include a first bit controlling whether a first phase shift (e.g., 180°) is implemented.

As a specific non-limiting example, during operation in the first state, the first and second two-state phase shifters832and834respectively emit seventh and eighth signals838and840. The seventh signal838is phase shifted (e.g., by 180°) relative to the third signal824and the eighth signal840is phase shifted (e.g., by 180°) relative to the fourth signal828. As a result, the third signal824and the eighth signal840are in-phase with each other (e.g., have a phase of 0°). Also, the fourth signal828and the seventh signal838are in-phase with each other (e.g., have a phase of 180°). Accordingly, the antenna structure801emits high-power microwaves having a first polarization (e.g., vertical polarization).

As another specific non-limiting example, during operation in the second state, the seventh signal838and the third signal824are in-phase with each other and the eighth signal840and the fourth signal828are in-phase with each other. The third and seventh signals824and838are phase-shifted (e.g., by 180°) relative to the fourth and eighth signals828and840.

Accordingly, the antenna structure801emits high-power microwaves having a second polarization (e.g., horizontal polarization) different than the first polarization.

The third signal824is coupled to an input of an RF power amplifier842-1and the seventh signal838is coupled to an input of an RF power amplifier842-3. The fourth signal828is coupled to an input of an RF power amplifier842-2and the eighth signal840is coupled to an input of an RF power amplifier842-4. During operation, the power amplifiers842emit amplified RF signals that are equal in RF signal amplitude. As a result, each of the antenna elements802is equally excited in terms of power received.

FIG.9illustrates a third simplified block diagram of an electronic system900according to one or more embodiments. Various features of the electronic system900are substantially similar to those described with respect to the electronic systems700and800, so further description thereof is omitted for brevity. The electronic system900, in combination with an antenna structure901, enables selective emission of high-power microwaves having a selected polarization from among a plurality of polarizations. More particularly, the electronic system900and the antenna structure901enable emission of high-power microwaves having a vertical polarization, a horizontal polarization, a right-hand circular polarization, and/or a left-hand circular polarization. The electronic system900is coupled to an antenna structure901that is substantially similar to the antenna structure801.

The electronic system900includes an RF signal generator906having an output coupled to one or more driver amplifiers908, as described elsewhere herein. The driver amplifier(s)908generate an amplified RF signal914is coupled to an input of a 1800 hybrid coupler910. The 180° hybrid coupler910outputs a first signal916that is conveyed along a first set of transmission paths917. The 180° hybrid coupler910outputs a second signal918that is conveyed along a second set of transmission paths919. The first signal916corresponds to the amplified RF signal914and the second signal9816corresponds to the amplified RF signal914phase-shifted by 180°.

The first signal916is received by a 90° hybrid coupler920and the second signal918is received by a 90° hybrid coupler922. The 90° hybrid coupler920outputs a third signal924corresponding to the first signal916and outputs a fourth signal926corresponding to the first signal916phase-shifted by 90°. The 90° hybrid coupler922outputs a fifth signal928corresponding to the second signal918and outputs a sixth signal930corresponding to the second signal918phase-shifted by 90°.

The electronic system900includes a first four-state phase shifter932coupled to receive the fourth signal926. The electronic system900also includes a second four-state phase shifter934coupled to receive the sixth signal930. The first and second four-state phase shifters932and934respectively emit seventh and eighth signals938and940, which may output signals that are phase-shifted relative to an input thereto.

The electronic system900further includes a controller936coupled to and configured to control states of the first and second four-state phase shifters932and934. In some embodiments, the controller936generates an output that collectively controls a state of the first and second four-state phase shifters932and934. In some embodiments, the controller936generates separate outputs that individually control states of the first and second four-state phase shifters932and934.

The first and second four-state phase shifters932and934are configured to operate, according to a first control signal from the controller936, in a first state in which an output thereof is not phase-shifted relative to an input. As a specific non-limiting example, during operation in the first state, the seventh signal938is phase shifted by 90° relative to the third signal924, the fifth signal928is phase shifted by 180° relative to the third signal924, and the eighth signal940is phase shifted by 270° relative to the third signal924. As a result, the antenna structure901emits high-power microwaves having a right-hand circular polarization.

The first and second four-state phase shifters932and934are configured to operate, according to a second control signal from the controller936, in a second state in which an output thereof is phase-shifted by a first amount (e.g., 180°) relative to an input thereto. As a specific non-limiting example, during operation in the second state, the seventh signal938is phase shifted by 270° relative to the third signal924, the fifth signal928is phase shifted by 180° relative to the third signal924, and the eighth signal940is phase shifted by 90° relative to the third signal924. As a result, the antenna structure901emits high-power microwaves having a left-hand circular polarization.

The first and second four-state phase shifters932and934are configured to operate, according to a third control signal from the controller936, in a third state in which an output thereof is phase-shifted by a second amount (e.g., 90°) relative to an input thereto. As a specific non-limiting example, during operation in the third state, the seventh signal938is phase shifted by 180° relative to the third signal924, the fifth signal928is phase shifted by 180° relative to the third signal924, and the eighth signal940is phase shifted by 0° relative to the third signal924. As a result, the antenna structure901emits high-power microwaves having a vertical polarization.

The first and second four-state phase shifters932and934are configured to operate, according to a third control signal from the controller936, in a fourth state in which an output thereof is phase-shifted by a fourth amount (e.g., 270°) relative to an input thereto. As a specific non-limiting example, during operation in the third state, the seventh signal938is phase shifted by 0° relative to the third signal924, the fifth signal928is phase shifted by 180° relative to the third signal924, and the eighth signal940is phase shifted by 180° relative to the third signal924. As a result, the antenna structure901emits high-power microwaves having a horizontal polarization.

The third signal924is coupled to an input of an RF power amplifier942-1and the seventh signal939is coupled to an input of an RF power amplifier942-3. The fourth signal929is coupled to an input of an RF power amplifier942-2and the eighth signal940is coupled to an input of an RF power amplifier942-4. During operation, the power amplifiers942emit amplified RF signals that are equal in RF signal amplitude. As a result, each of the antenna elements902is equally excited in terms of power received.

Operational states of the electronic system900relative to polarization of high-power microwaves emitted by the antenna structure901may be summarized according to the following Table 2 relative bit states of the four-state phase shifters932and934, and the phase-shifts of the signals938,928, and940relative to the signal924:

Those skilled in the art will appreciate that the electronic systems and associated antenna structures may be modified to achieve different or greater scopes of polarization. For instance, the number of antenna elements and/or feeds may be increased to eight to enable diagonal polarizations in addition to those described herein. The electronic system may be modified accordingly by increasing the number of transmission paths and adjusting the amounts of phase shifting associated with each bit state of the phase shifters.

FIG.10illustrates a two-state phase shifter1000according to one or more embodiments. The two-state phase shifter1000may be implemented, for example, in the electronic system800. The phase shifter1000shown is a switched line phase shifter but may be implemented in a variety of other ways as discussed below. The phase shifter1000includes a first RF signal path1002, a second RF signal path1004, a signal input1006, a first switching device1008, a signal output1010, and a second switching device1012. The first switching device1008is a single-pole double-throw (SPDT) switching device coupled between the signal input1006and the first and second signal paths1002and1004. The second switching device1012is a SPDT switching device coupled between the signal output1010and the first and second signal paths1002and1004. The SPDT switching devices may be implemented using field-effect transistors (FETs), diodes, mechanical switches, or micro-electro-mechanical-system (MEMS) devices.

The first signal path1002has a first path length providing a first phase shift (e.g., 0°) for a given frequency or range of frequencies of a signal passed therethrough. The second signal path1002has a second path length providing a second phase shift (e.g., 90°, 180°) for the given frequency or range of frequencies of a signal passed therethrough. The first and second switching devices1008and1012collectively switch between connection to the first and second signal paths1002and1004.

The phase shifter1000includes control circuitry or logic1014(e.g., Boolean logic, TTL) and a control input terminal1016for receiving a signal (e.g., analog signal, digital signal) to control a signal path state of the phase shifter1000. The phase shifter1000is an example of one implementation of a two-state phase shifter1000, which may be implemented in a variety of other ways. For instance, the two-state phase shifter1000may be implemented as a high-pass/low-pass phase shifter or a passive reciprocal phase shifter, by way of non-limiting example.

FIG.11shows a four-state phase shifter1100according to one or more embodiments.

The four-state phase shifter1100may be implemented, for example, in the electronic system700or the electronic system900. The phase shifter1100shown is comprised of switched line phase shifters but may be implemented in a variety of other ways. The phase shifter1100includes a first two-state phase shifter1102and a second two-state phase shifter1104connected in series with the first two-state phase shifter1102. Each of the first and second phase shifters1102and1104include a pair of SPDT switching devices that collectively transition between connection to a first signal path and a second signal path to adjust a phase shift of the signal passed therethrough.

The first phase shifter1102includes a first signal path1106having a first path length providing a first phase shift (e.g., 0°) for a given frequency or range of frequencies of a signal passed therethrough. The first phase shifter1102also includes a second signal path1108having a second path length providing a second phase shift (e.g., 180°) for a given frequency or range of frequencies of a signal passed therethrough. The second phase shifter1104includes a third signal path1110having the first path length providing the first phase shift (e.g., 0°) for a given frequency or range of frequencies of a signal passed therethrough. The second phase shifter1104includes a fourth signal path1112having a fourth path length providing a third phase shift (e.g., 90°) for a given frequency or range of frequencies of a signal passed therethrough. The second phase shift of the second signal path1108is different than the third phase shift of the fourth signal path1112.

The phase shifter1100also includes control circuitry or logic1114(e.g., Boolean logic, TTL) and a set of control input terminals1116for receiving signals (e.g., analog signals, digital signals) to control a signal path state of the first and second phase shifters1102and1104. As discussed above with respect toFIG.10, the four-state phase shifter1100may be implemented using high-pass/low-pass phase shifters or passive reciprocal phase shifters, by way of non-limiting example.

FIG.12illustrates a simplified block diagram of a phased array system1200according to one or more embodiments. The phased array system1200includes a central computer1202, an RF signal generator1204, an array of amplifier modules1206, and an antenna array1208.

In some embodiments, the phased array system1200may include a target detector1210comprising one or more sensors (e.g., electro-optical, radar, infrared) configured to detect targets, such as unmanned aerial vehicles.

The central computer1202comprises one or more CPUs1212coupled to memory1214. The memory1214may store instructions that, as a result of execution by the one or more CPUs1212, cause the central computer1202to perform operations described herein. The memory1214, for instance, may store target classification instructions1216that enable the one or more CPUs1212to classify a target detected. The memory1214may also store a waveform data structure1218, such as a look up table (LUT), that specifies waveform parameters. The memory1214may further store waveform selector instructions1220that enable the one or more CPUs1212to select waveform parameters based on the classification of the target detected. The waveform selector instructions1220may access one or more locations in the waveform data structure1218as a result of executing the waveform selector instructions1220.

The RF signal generator1204, in some embodiments, is implemented as an RF system on a Chip Field Programmable Gate Array (RFSoC FPGA). The signal generator1204may include a direct digital synthesizer (DDS)1222that digitally generates a signal having a desired frequency. The DDS1220, for instance, may create waveforms of the frequency, pulse width, pulse repetition interval and intra-pulse modulation specified by the RF frequency waveform parameters generated by the central computer1202. The gate array1224is configured to perform a variety of functions including, but not limited to, determining the time intervals at which different components of an amplifier module is powered up and powered down. The digital waveforms are passed to a set of digital-to-analog (DAC) converters1226-1,1226-2, . . . ,1226-N (collectively “DACs1226”).

Outputs from the DACs1226may be provided to a set of signal conditioning units (SCUs)1228-1,1228-2, . . . ,1228-N (collectively “SCUs1228”). In various implementations, the SCUs1228may comprise filters that filter the RF signals according to a frequency band of interest. In some implementations, the SCUs1228can comprise one or more phase shifters and/or attenuators that can achieve the desired azimuth and elevation angles for an RF beam to be generated. Each of the SCUs may, for instance, adjust a phase of the RF signal passed therethrough to achieve the desired azimuth and elevation angles of electromagnetic radiation to be emitted by the phased array system1200.

The outputs from the RF signal generator1204are provided to the amplifier module array1206, which includes a plurality of electronic systems1230-1,1230-2, . . .1230-N (collectively “electronic systems1230”). The electronic systems1230individually correspond to the electronic system700, the electronic system800, the electronic system900, or variants thereof. The central computer1202is configured to control various aspects of the amplifier module array1206. For instance, the central computer1202may transmit signals causing the electronic systems1230to transition to operate in a desired state among a plurality of selectable states, each of the selectable states corresponding to a desired polarization of high-power microwaves to be emitted from the antenna array1208. The central computer1202may control other aspects of the amplifier module array1208, such as causing a defined gate bias to be applied to individual RF power amplifiers of the electronic systems1230. The electronic systems1230may each be contained within a separate module that includes a housing.

The antenna array1208comprises a plurality of antenna structures1232-1,1232-2, . . .1232-N (collectively “antenna structures1232”). The antenna structures1232-1,1232-2, . . .1232-N individually correspond to the antenna structure100or the antenna structure500(see, e.g.,FIG.1,FIG.5). Each of the electronic systems1230is coupled to an individual antenna structure of the antenna structures1232. In some embodiments, the electronic systems1230and the antenna structures1232are arranged in an N×N array or an M×N array, wherein N and M are integer values. In such embodiments, each antenna structure1232is coupled directly to the four output ports of an individual electronic system of the electronic systems1230.

The RF signal generator1204allows digital formation of signal beams which has several advantages including but not limited to increasing/maximizing signal power in certain regions of space and decreasing/minimizing signal power in certain other regions of space. Accordingly, signal power can be focused on targets in certain regions of space while reducing the signal power on targets in certain other regions of space. Digitally forming signal beams as discussed above also advantageously allow the power, frequency and other parameters of the signal beam to be changed in sufficiently real time (e.g., in less than 1 millisecond).

The central computer1202may be configured to classify targets (e.g., by type) and select RF waveform parameters based on the target classification. The central computer1202passes the RF waveform parameters to the RF signal generator1204. The RF waveform parameters include a waveform polarization type in some embodiments. In various implementations, the RF signal generator1204is programmable and controlled by the computer1202to change various parameters of the generated RF signal including but not limited to frequency and power of the RF signal. The RF signal generator1204creates RF signals in accordance with the RF waveform parameters. Each RF signal has a waveform of the frequency, pulse width, pulse repetition interval, and/or intra-pulse modulation specified by the RF waveform parameters received from the central computer1202. The frequency, pulse width, pulse repetition interval and intra-pulse modulation of the generated RF signal can be changed by the computer1202in real time or in substantially real time.

The RF signal generator1204produces RF signals for multiple channels that are applied to the electronic systems1230. The RF signals for the multiple channels are phase shifted relative to one another in accordance with RF frequency waveform parameters. In one embodiment, the phase shifting is digitally performed within the RF signal generator1204. Alternately, analog phase shifters may shift the RF signals prior to applying them to the electronic systems1230. In some implementations, the amplitude of some of the RF signals for the multiple channels can be attenuated as compared to the amplitude of some other of the RF signals for the multiple channels. Although, in the illustrated implementation, the computer1202is distinct from the RF signal generator1204, in various other implementations, the computer1202and the RF signal generator1204can be integrated together. Each electronic system1230has a plurality of solid-state power amplifiers, each of which has a gate voltage on set point derived from an automatic calibration operation. Some of the plurality of solid-state power amplifiers may be arranged serially/sequentially in some implementations. Some of the plurality of solid-state power amplifiers may be arranged in a power combining configuration. Each amplifier chain produces an amplified RF signal. In one embodiment, a few mW RF signal from the RF signal generator1204is amplified to a few kWs. The amplifier chain may utilize a combination of solid-state amplifiers, including silicon laterally diffused metal-oxide semiconductors, Gallium Nitride, Scandium Aluminum Nitride, Gallium Arsenide, and Indium Phosphide.

Other Variations

While certain embodiments have been described, these embodiments have been presented by way of example only and are not intended to limit the scope of protection.

Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes disclosed and/or illustrated may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. For example, the actual steps and/or order of steps taken in the disclosed processes may differ from those described and/or shown in the figure. Depending on the embodiment, certain of the steps described above may be removed, others may be added. For instance, the various components illustrated in the figures and/or described may be implemented as software and/or firmware on a processor, controller, ASIC, FPGA, and/or dedicated hardware. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure.

In some cases, there is provided a non-transitory computer readable medium storing instructions, which when executed by at least one computing or processing device, cause performing any of the methods as generally shown or described herein and equivalents thereof.

Any of the memory components described herein can include volatile memory, such random-access memory (RAM), dynamic random-access memory (DRAM), synchronous dynamic random-access memory (SDRAM), double data rate (DDR) memory, static random-access memory (SRAM), other volatile memory, or any combination thereof. Any of the memory components described herein can include non-volatile memory, such as magnetic storage, flash integrated circuits, read only memory (ROM), Chalcogenide random access memory (C-RAM), Phase Change Memory (PC-RAM or PRAM), Programmable Metallization Cell RAM (PMC-RAM or PMCm), Ovonic Unified Memory (OUM), Resistance RAM (RRAM), NAND memory (e.g., single-level cell (SLC) memory, multi-level cell (MLC) memory, or any combination thereof), NOR memory, EEPROM, Ferroelectric Memory (FeRAM), Magnetoresistive RAM (MRAM), other discrete NVM (non-volatile memory) chips, or any combination thereof.

Any user interface screens illustrated and described herein can include additional and/or alternative components. These components can include menus, lists, buttons, text boxes, labels, radio buttons, scroll bars, sliders, checkboxes, combo boxes, status bars, dialog boxes, windows, and the like. User interface screens can include additional and/or alternative information. Components can be arranged, grouped, displayed in any suitable order.

Unless otherwise explicitly stated, articles such as “a” or “an” should generally be interpreted to include one or more described items. Accordingly, phrases such as “a device configured to” are intended to include one or more recited devices. Such one or more recited devices can also be collectively configured to carry out the stated recitations.

The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the disclosure. However, it will be apparent to one skilled in the art that specific details are not required in order to practice the disclosed embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed; obviously, many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, they thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the claims as presented herein or as presented in the future and their equivalents define the scope of the protection.