Abstract: A full band waveguide orthomode transducer (OMT) includes first, second, and third waveguide sections coupled to one another, the first, second, and third waveguide sections respectively having a first port, a second port, and a third port. A first wire grid polarizer in the first waveguide section is transparent to electromagnetic signals having a first polarization and reflective of electromagnetic signals having a second polarization orthogonal to the first polarization. A second wire grid polarizer in the second waveguide section is transparent to electromagnetic signals having the second polarization and reflective of electromagnetic signals having the first polarization. The third waveguide section is configured to transmit and/or receive electromagnetic signals having the first polarization and/or the second polarization.

Abstract: A full band waveguide orthomode transducer (OMT) includes first, second, and third waveguide sections coupled to one another, the first, second, and third waveguide sections respectively having a first port, a second port, and a third port. A first wire grid polarizer in the first waveguide section is transparent to electromagnetic signals having a first polarization and reflective of electromagnetic signals having a second polarization orthogonal to the first polarization. A second wire grid polarizer in the second waveguide section is transparent to electromagnetic signals having the second polarization and reflective of electromagnetic signals having the first polarization. The third waveguide section is configured to transmit and/or receive electromagnetic signals having the first polarization and/or the second polarization.

Abstract: A full band waveguide orthomode transducer (OMT) includes first, second, and third waveguide sections coupled to one another, the first, second, and third waveguide sections respectively having a first port, a second port, and a third port. A first wire grid polarizer in the first waveguide section is transparent to electromagnetic signals having a first polarization and reflective of electromagnetic signals having a second polarization orthogonal to the first polarization. A second wire grid polarizer in the second waveguide section is transparent to electromagnetic signals having the second polarization and reflective of electromagnetic signals having the first polarization. The third waveguide section is configured to transmit and/or receive electromagnetic signals having the first polarization and/or the second polarization.

Abstract: A scanning antenna system includes a feed line having first and second ends, and a scanning antenna element disposed with respect to the feed line so that, in the transmit mode, a signal input to one of the first and second ends of the feed line is evanescently coupled to the antenna element, whereby the antenna element radiates the signal as a shaped beam through an angular scanning field having a negative angular scanning space and a positive angular scanning space on either side of the stop band near 0°. A switching network, operatively coupled to the feed line, switches the signal input between the first and second ends of the feed line in a controlled sequence, whereby the shaped beam radiated by the antenna element is scanned in the negative scanning space, the stop band, and the positive scanning space. The antenna system performs reciprocally in the receive mode.

Abstract: A scanning antenna system includes a feed line having first and second ends, and a scanning antenna element disposed with respect to the feed line so that, in the transmit mode, a signal input to one of the first and second ends of the feed line is evanescently coupled to the antenna element, whereby the antenna element radiates the signal as a shaped beam through an angular scanning field having a negative angular scanning space and a positive angular scanning space on either side of the stop band near 0°. A switching network, operatively coupled to the feed line, switches the signal input between the first and second ends of the feed line in a controlled sequence, whereby the shaped beam radiated by the antenna element is scanned in the negative scanning space, the stop band, and the positive scanning space. The antenna system performs reciprocally in the receive mode.

Abstract: A waveguide includes a dielectric substrate having first and second opposed surfaces defining a longitudinal wave propagation path therebetween; and a conductive grid on the first surface of the substrate and comprising a plurality of substantially parallel metal strips, each defining an axis. The grid renders the first surface of the substrate opaque to a longitudinal electromagnetic wave propagating along the longitudinal wave propagation path and polarized in a direction substantially parallel to the axes of the strips. The grid allows the first surface of the substrate to be transparent to a transverse electromagnetic wave having a transverse propagation path that intersects the first and second surfaces of the substrate and having a polarization in a direction substantially normal to the plurality of metal strips. A diffraction grating on the second surface allows the waveguide to function as an antenna element that may be employed in a beam-steering antenna system.

Abstract: A waveguide includes a dielectric substrate having first and second opposed surfaces defining a longitudinal wave propagation path therebetween; and a conductive grid on the first surface of the substrate and comprising a plurality of substantially parallel metal strips, each defining an axis. The grid renders the first surface of the substrate opaque to a longitudinal electromagnetic wave propagating along the longitudinal wave propagation path and polarized in a direction substantially parallel to the axes of the strips. The grid allows the first surface of the substrate to be transparent to a transverse electromagnetic wave having a transverse propagation path that intersects the first and second surfaces of the substrate and having a polarization in a direction substantially normal to the plurality of metal strips. A diffraction grating on the second surface allows the waveguide to function as an antenna element that may be employed in a beam-steering antenna system.

Abstract: A waveguide includes a dielectric substrate having first and second opposed surfaces defining a longitudinal wave propagation path therebetween; and a conductive grid on the first surface of the substrate and comprising a plurality of substantially parallel metal strips, each defining an axis. The grid renders the first surface of the substrate opaque to a longitudinal electromagnetic wave propagating along the longitudinal wave propagation path and polarized in a direction substantially parallel to the axes of the strips. The grid allows the first surface of the substrate to be transparent to a transverse electromagnetic wave having a transverse propagation path that intersects the first and second surfaces of the substrate and having a polarization in a direction substantially normal to the plurality of metal strips. A diffraction grating on the second surface allows the waveguide to function as an antenna element that may be employed in a beam-steering antenna system.

Abstract: An electronically controlled monolithic array antenna includes a transmission line through which an electromagnetic signal may be propagated, and a metal antenna element defining an evanescent coupling edge located so as to permit evanescent coupling of the signal between the transmission line and the antenna element. The antenna element includes a conductive ground plate; an array of conductive edge elements defining the coupling edge, each of the edge elements being electrically connected to a control signal source, and each of the edge elements being electrically isolated from the ground plate by an insulative isolation gap; and a plurality of switches, each of which is selectively operable in response to the control signal to electrically connect selected edge elements to the ground plate across the insulative isolation gap so as to provide a selectively variable electromagnetic coupling geometry of the coupling edge.

Abstract: A microwave switch array includes a plurality of microwave slotlines, each of which is controlled by a semiconductor switch including a first PIN junction formed by a primary P-type electrode and a primary N-type electrode separated by the slotline. The switches inject a plasma into the slotline in response to a potential applied across the first PIN junction. Each of the switches includes a second PIN junction between the primary P-type electrode and a secondary N-type electrode, and a third PIN junction between the primary N-type electrode and a secondary P-type electrode. Metal contacts connect the primary P-type electrode and the secondary N-type electrode across second PIN junction, and the primary N-type electrode and the secondary P-type electrode across the third PIN junction. The secondary electrodes extract plasma that diffuses away from the first PIN junction, thereby minimizing the performance degrading effects of plasma diffusion.

Abstract: A scanning antenna with an antenna element having an evanescent coupling portion includes a waveguide assembly including a transmission line, adjacent the coupling portion, through which an electromagnetic signal is transmitted, permitting evanescent coupling of the signal between the transmission line and the antenna element. First and second conductive waveguide plates, on opposite sides of the transmission line, define planes that are substantially parallel to the axis of the transmission line, each plate extending distally from a proximal end adjacent the antenna element, whereby the propagated signal forms a beam that is confined to the space between the plates and thus limited to a plane that is parallel to the planes defined by the plates. The signal coupled between the transmission line and the antenna element is preferably polarized so that its electric field component is in a plane parallel to the planes defined by the plates.

Abstract: A waveguide includes a dielectric substrate having first and second opposed surfaces defining a longitudinal wave propagation path therebetween; and a conductive grid on the first surface of the substrate and comprising a plurality of substantially parallel metal strips, each defining an axis. The grid renders the first surface of the substrate opaque to a longitudinal electromagnetic wave propagating along the longitudinal wave propagation path and polarized in a direction substantially parallel to the axes of the strips. The grid allows the first surface of the substrate to be transparent to a transverse electromagnetic wave having a transverse propagation path that intersects the first and second surfaces of the substrate and having a polarization in a direction substantially normal to the plurality of metal strips. A diffraction grating on the second surface allows the waveguide to function as an antenna element that may be employed in a beam-steering antenna system.

Abstract: An electronically controlled monolithic array antenna includes a transmission line through which an electromagnetic signal may be propagated, and a metal antenna element defining an evanescent coupling edge located so as to permit evanescent coupling of the signal between the transmission line and the antenna element. The antenna element includes a conductive ground plate; an array of conductive edge elements defining the coupling edge, each of the edge elements being electrically connected to a control signal source, and each of the edge elements being electrically isolated from the ground plate by an insulative isolation gap; and a plurality of switches, each of which is selectively operable in response to the control signal to electrically connect selected edge elements to the ground plate across the insulative isolation gap so as to provide a selectively variable electromagnetic coupling geometry of the coupling edge.

Abstract: An electronically controlled monolithic array antenna includes a transmission line through which an electromagnetic signal may be propagated, and a metal antenna element defining an evanescent coupling edge located so as to permit evanescent coupling of the signal between the transmission line and the antenna element. The antenna element includes a conductive ground plate; an array of conductive edge elements defining the coupling edge, each of the edge elements being electrically connected to a control signal source, and each of the edge elements being electrically isolated from the ground plate by an insulative isolation gap; and a plurality of switches, each of which is selectively operable in response to the control signal to electrically connect selected edge elements to the ground plate across the insulative isolation gap so as to provide a selectively variable electromagnetic coupling geometry of the coupling edge.

Abstract: A scanning antenna with an antenna element having an evanescent coupling portion includes a waveguide assembly including a transmission line, adjacent the coupling portion, through which an electromagnetic signal is transmitted, permitting evanescent coupling of the signal between the transmission line and the antenna element. First and second conductive waveguide plates, on opposite sides of the transmission line, define planes that are substantially parallel to the axis of the transmission line, each plate extending distally from a proximal end adjacent the antenna element, whereby the propagated signal forms a beam that is confined to the space between the plates and thus limited to a plane that is parallel to the planes defined by the plates. The signal coupled between the transmission line and the antenna element is preferably polarized so that its electric field component is in a plane parallel to the planes defined by the plates.

Abstract: An electronically controlled monolithic array antenna includes a transmission line through which an electromagnetic signal may be propagated, and a metal antenna element defining an evanescent coupling edge located so as to permit evanescent coupling of the signal between the transmission line and the antenna element. The antenna element includes a conductive ground plate; an array of conductive edge elements defining the coupling edge, each of the edge elements being electrically connected to a control signal source, and each of the edge elements being electrically isolated from the ground plate by an insulative isolation gap; and a plurality of switches, each of which is selectively operable in response to the control signal to electrically connect selected edge elements to the ground plate across the insulative isolation gap so as to provide a selectively variable electromagnetic coupling geometry of the coupling edge.

Abstract: A microwave switch array includes a plurality of microwave slotlines, each of which is controlled by a semiconductor switch including a first PIN junction formed by a primary P-type electrode and a primary N-type electrode separated by the slotline. The switches inject a plasma into the slotline in response to a potential applied across the first PIN junction. Each of the switches includes a second PIN junction between the primary P-type electrode and a secondary N-type electrode, and a third PIN junction between the primary N-type electrode and a secondary P-type electrode. Metal contacts connect the primary P-type electrode and the secondary N-type electrode across second PIN junction, and the primary N-type electrode and the secondary P-type electrode across the third PIN junction. The secondary electrodes extract plasma that diffuses away from the first PIN junction, thereby minimizing the performance degrading effects of plasma diffusion.

Abstract: A reconfigurable directional antenna for transmission and reception of electromagnetic radiation includes a transmission line aligned with and adjacent to a metal antenna element with an evanescent coupling edge having a selectively variable electromagnetic coupling geometry. The shape and direction of the beam are determined by the selected coupling geometry of the coupling edge, as determined by the pattern of electrical connections selected for physical edge features of the coupling edge. The electrical connections between the edge features are selected by the selective actuation of an array of “on-off” switches that close and open electrical connections between individual edge features. The selection of the “on” or “off” state of the individual switches thus changes the electromagnetic geometry of the coupling edge, and, therefore the direction and shape of the transmitted or received beam. The actuation of the switches may be accomplished under the control of an appropriately-programmed computer.

Abstract: A reconfigurable directional antenna for transmission and reception of electromagnetic radiation includes a transmission line aligned with and adjacent to a metal antenna element with an evanescent coupling edge having a selectively variable electromagnetic coupling geometry. The shape and direction of the beam are determined by the selected coupling geometry of the coupling edge, as determined by the pattern of electrical connections selected for physical edge features of the coupling edge. The electrical connections between the edge features are selected by the selective actuation of an array of “on-off” switches that close and open electrical connections between individual edge features. The selection of the “on” or “off” state of the individual switches thus changes the electromagnetic geometry of the coupling edge, and, therefore the direction and shape of the transmitted or received beam. The actuation of the switches may be accomplished under the control of an appropriately-programmed computer.

Abstract: A method reduces movement of a reflector in an unintended mechanical mode during movement of the reflector in an intended mechanical mode. The method includes using a reflector driver to apply a distribution of forces to the reflector so as to move the reflector in both the intended mechanical mode and in the unintended mechanical mode. The distribution of forces is applied at a resonant frequency of the unintended mechanical mode. The method further includes adjusting the reflector driver to alter the distribution of forces applied to the reflector such that the movement of the reflector in the unintended mechanical mode is reduced.