Abstract: A cavity-backed slot antenna whose cavity has an artificial magnetic conductor (AMC) disposed therein, the AMC being loaded with active reactive elements. The active reactive elements are preferably formed by Non-Foster Circuits (NFCs).

Abstract: A reconfigurable electro-magnetic tile includes a laser layer including a plurality of lasers, and a pixelated surface comprising a plurality of metal patches and a plurality of switches, wherein each respective switch of the plurality of switches is in a gap between a first respective metal patch and a second respective metal patch, wherein each respective switch is optically coupled to at least one respective laser of the plurality of lasers, and wherein each switch of the plurality of switches comprises a phase change material.

Abstract: A method for fabricating and installing an artificial impedance surface antenna (AISA) includes locating a substantially flat surface having a line of sight to a satellite or satellites of interest, determining an angle ?o between a normal to the substantially flat surface and a direction to the satellite or satellites of interest, selecting an antenna superstrate from a pre-fabbed stock of antenna superstrates, the selected antenna superstrate configured for having a peak radiation within two (2) degrees of the angle ?o, laminating the selected antenna superstrate to an antenna substrate to form the AISA, and mounting the AISA on the substantially flat surface.

Abstract: A flexible, printable antenna for automotive radar. The antenna can be printed onto a thin, flexible substrate, and thus can be bent to conform to a vehicle body surface with compound curvature. The antenna can be mounted to the interior of a body surface such as a bumper fascia, where it cannot be seen but can transmit radar signals afield. The antenna can also be mounted to and blended into the exterior of an inconspicuous body surface, or can be made transparent and mounted to the interior or exterior of a glass surface. The antenna includes an artificial impedance surface which is tailored based on the three-dimensional shape of the surface to which the antenna is mounted and the desired radar wave pattern. The antenna can be used for automotive collision avoidance applications using 22-29 GHz or 76-81 GHz radar, and has a large aperture to support high angular resolution of radar data.

Abstract: The disclosed antenna structures and electronic microsystems are capable of physically disappearing in a controlled, triggerable manner. Some variations provide an on-chip transient antenna comprising a semiconductor substrate containing ion-implanted hydrogen atoms and a conductor network comprising metals bridged by low-melting-temperature metals. Some variations provide an off-chip transient antenna comprising a flexible substrate containing a polymer, nanoporous silicon particles, and an oxidant for silicon, and a conductor network comprising metals bridged by low-melting-temperature metals. Other variations provide a method of introducing physical transience to a semiconductor integrated circuit, comprising thinning a substrate from the back side, implanting hydrogen ions into the thinned substrate to introduce latent structural flaws, depositing a semiconductor integrated circuit or sensor chip, and providing a controllable heating source capable of activating the latent structural flaws.

Abstract: A steerable artificial impedance surface antenna steerable in phi and theta angles including a dielectric substrate, a plurality of metallic strips on a first surface of the dielectric substrate, the metallic strips spaced apart across a length of the dielectric substrate and each metallic strip extending along a width of the dielectric substrate, and surface wave feeds spaced apart along the width of the dielectric substrate near an edge of the dielectric substrate, wherein the dielectric substrate is substantially in an X-Y plane defined by an X axis and a Y axis, wherein the phi angle is an angle in the X-Y plane relative to the X axis, and wherein the theta angle is an angle relative to a Z axis orthogonal to the X-Y plane.

Abstract: An automatic tuning circuit for matching an antenna to a radio receiver. The automatic tuning circuit includes a tunable non-Foster circuit for coupling the receiver and the antenna; and sensing and feedback circuits for sensing the combined capacitance of the tunable non-Foster circuit and the antenna and for tuning the tunable non-Foster circuit to automatically minimize the combined capacitance of the tunable non-Foster circuit and the antenna.

Abstract: Methods for disambiguating the location of a radar contact using an N×M dimensioned radar array are provided. In the horizontal plane, the method comprises transmitting a first radar energy pattern in a direction, collecting reflected energy of the first radar energy pattern from the contact, transmitting a second radar energy pattern in the direction and collecting reflected energy of the second radar energy pattern from the contact. The method further comprises comparing the collected energy of the first radar energy pattern and the collected energy of the second radar energy pattern and determining if the contact is located in a side lobe or a main lobe of the first and second radar energy pattern based on the comparison. In the vertical plane, other similar embodiments may be used to determine if the radar antenna(s) are blocked by an obstacle.

Abstract: A flexible, printable antenna for automotive radar. The antenna can be printed onto a thin, flexible substrate, and thus can be bent to conform to a vehicle body surface with compound curvature. The antenna can be mounted to the interior of a body surface such as a bumper fascia, where it cannot be seen but can transmit radar signals afield. The antenna can also be mounted to and blended into the exterior of an inconspicuous body surface, or can be made transparent and mounted to the interior or exterior of a glass surface. The antenna includes an artificial impedance surface which is tailored based on the three-dimensional shape of the surface to which the antenna is mounted and the desired radar wave pattern. The antenna can be used for automotive collision avoidance applications using 22-29 GHz or 76-81 GHz radar, and has a large aperture to support high angular resolution of radar data.

Abstract: A reconfigurable electro-magnetic tile includes a laser layer including a plurality of lasers, and a pixelated surface comprising a plurality of metal patches and a plurality of switches, wherein each respective switch of the plurality of switches is in a gap between a first respective metal patch and a second respective metal patch, wherein each respective switch is optically coupled to at least one respective laser of the plurality of lasers, and wherein each switch of the plurality of switches comprises a phase change material.

Abstract: A system for measuring properties of a surface under test with surface waves includes a surface wave network including a dielectric substrate, a reactive grid of a plurality of metallic patches on a first surface of the dielectric substrate, a plurality of electronic nodes on the first surface of the dielectric substrate, and a ground plane on a second surface of the dielectric substrate permeable to RF fields of the surface waves, and a controller configured for causing a respective one of the electronic nodes to transmit at least one surface wave and configured for collecting data for signals received by at least one other of the plurality of electronic nodes.

Abstract: A differential circuit topology that produces a tunable floating negative inductance, negative capacitance, negative resistance/conductance, or a combination of the three. These circuits are commonly referred to as “non-Foster circuits.” The disclosed embodiments of the circuits comprises two differential pairs of transistors that are cross-coupled, a load immittance, multiple current sources, two Common-Mode FeedBack (CMFB) networks, at least one tunable (variable) resistance, and two terminals across which the desired immittance is present. The disclosed embodiments of the circuits may be configured as either a Negative Impedance Inverter (NII) or a Negative Impedance Converter (NIC) and as either Open-Circuit-Stable (OCS) and Short-Circuit-Stable (SCS).

Abstract: A method of and apparatus for mitigating adverse transmission and/or reception effects that an obstruction would otherwise have upon a RF signal to be transmitted or received, the RF signal being available at a feed point and wherein the obstruction is spaced from the feed point in a direction of desired transmission or reception. An artificial impedance surface is disposed adjacent the feed point and the obstruction, and the artificial impedance surface is designed (i) to have a spatially non-varying impedance function in a constant impedance region at least immediately adjacent the feed point and (ii) to have a non-constant impedance function in one or more regions spaced from the feed point and closer to the obstruction.

Abstract: A tunable impedance surface, the tunable surface including a plurality of elements disposed in a two dimensional array; and an arrangement of variable negative reactance circuits for controllably varying negative reactance between at least selected ones of adjacent elements in the aforementioned two dimensional array.

Abstract: A steerable artificial impedance surface antenna steerable in phi and theta angles including a dielectric substrate, a plurality of metallic strips on a first surface of the dielectric substrate, the metallic strips spaced apart across a length of the dielectric substrate and each metallic strip extending along a width of the dielectric substrate, and surface wave feeds spaced apart along the width of the dielectric substrate near an edge of the dielectric substrate, wherein the dielectric substrate is substantially in an X-Y plane defined by an X axis and a Y axis, wherein the phi angle is an angle in the X-Y plane relative to the X axis, and wherein the theta angle is an angle relative to a Z axis orthogonal to the X-Y plane.

Abstract: Methods for disambiguating the location of a radar contact using an N×M dimensioned radar array are provided. In the horizontal plane, the method comprises transmitting a first radar energy pattern in a direction, collecting reflected energy of the first radar energy pattern from the contact, transmitting a second radar energy pattern in the direction and collecting reflected energy of the second radar energy pattern from the contact. The method further comprises comparing the collected energy of the first radar energy pattern and the collected energy of the second radar energy pattern and determining if the contact is located in a side lobe or a main lobe of the first and second radar energy pattern based on the comparison. In the vertical plane, other similar embodiments may be used to determine if the radar antenna(s) are blocked by an obstacle.

Abstract: A method for fabricating and installing an artificial impedance surface antenna (AISA) includes locating a substantially flat surface having a line of sight to a satellite or satellites of interest, determining an angle ?o between a normal to the substantially flat surface and a direction to the satellite or satellites of interest, selecting an antenna superstrate from a pre-fabbed stock of antenna superstrates, the selected antenna superstrate configured for having a peak radiation within two (2) degrees of the angle ?o, laminating the selected antenna superstrate to an antenna substrate to form the AISA, and mounting the AISA on the substantially flat surface.

Abstract: A system for measuring properties of a surface under test with surface waves includes a surface wave network including a dielectric substrate, a reactive grid of a plurality of metallic patches on a first surface of the dielectric substrate, a plurality of electronic nodes on the first surface of the dielectric substrate, and a ground plane on a second surface of the dielectric substrate permeable to RF fields of the surface waves, and a controller configured for causing a respective one of the electronic nodes to transmit at least one surface wave and configured for collecting data for signals received by at least one other of the plurality of electronic nodes.

Abstract: A vehicle or other host station includes first and second antennas, a fast semiconductor switch, a switching controller, and an RF receiver. The controller toggles the switch at a calibrated switching rate to selectively and alternately connect the first antenna to one of the RF receiver and a load having a calibrated impedance value. The first antenna may be a parasitic element in any embodiment using the load. The semiconductor switch may be a CMOS device or a Gallium Arsenide semiconductor switch. A switching control method for use in a vehicle or other host station having the first antenna, the second antenna, and the RF receiver includes transmitting a switching signal from the controller to the switch, and toggling the switch at a calibrated switching rate in response to the switching signal to selectively and alternately connect the first antenna to one of the RF receiver and the load.

Abstract: A method of delaying the onset of a backward wave mode in a frequency selective surface having a two dimensional array of conductive patches or elements and an RF ground plane, the two dimensional array of patches or elements being interconnected by variable capacitors, the method comprising separating grounds associated with the variable capacitors from the RF ground plane and providing a separate conductive mesh structure or arrangement as a bias voltage ground for the variable capacitors. A tunable impedance surface comprises a RF ground plane; a plurality of patches or elements disposed in an array a distance from the ground plane; a capacitor arrangement for controllably varying capacitance between at least selected ones of adjacent patches or elements in the array; and a grounding mesh associated with the capacitor arrangement for providing a control voltage ground to capacitors in the capacitor arrangement, the grounding mesh being spaced from the RF ground plane by dielectric material.