Abstract: A radio frequency transparent photovoltaic cell includes a back contact layer formed of an electrically conductive material, at least one aperture formed in the back contact layer, and at least one photovoltaic cell section disposed on the back contact layer. An airship includes one or more radio frequency antennas disposed in an interior of the airship. One or more radio frequency transparent photovoltaic cells are disposed on an outer surface of the airship.

Abstract: A radio frequency transparent photovoltaic cell includes a back contact layer formed of an electrically conductive material, at least one aperture formed in the back contact layer, and at least one photovoltaic cell section disposed on the back contact layer. An airship includes one or more radio frequency antennas disposed in an interior of the airship. One or more radio frequency transparent photovoltaic cells are disposed on an outer surface of the airship.

Abstract: A radio frequency transparent photovoltaic cell includes a back contact layer formed of an electrically conductive material, at least one aperture formed in the back contact layer, and at least one photovoltaic cell section disposed on the back contact layer. An airship includes one or more radio frequency antennas disposed in an interior of the airship. One or more radio frequency transparent photovoltaic cells are disposed on an outer surface of the airship.

Abstract: A radio frequency transparent photovoltaic cell includes a back contact layer formed of an electrically conductive material, at least one aperture formed in the back contact layer, and at least one photovoltaic cell section disposed on the back contact layer. An airship includes one or more radio frequency antennas disposed in an interior of the airship. One or more radio frequency transparent photovoltaic cells are disposed on an outer surface of the airship.

Abstract: A radio frequency transparent photovoltaic cell includes a back contact layer formed of an electrically conductive material, at least one aperture formed in the back contact layer, and at least one photovoltaic cell section disposed on the back contact layer. An airship includes one or more radio frequency antennas disposed in an interior of the airship. One or more radio frequency transparent photovoltaic cells are disposed on an outer surface of the airship.

Abstract: A radio frequency transparent photovoltaic cell includes a back contact layer formed of an electrically conductive material, at least one aperture formed in the back contact layer, and at least one photovoltaic cell section disposed on the back contact layer. An airship includes one or more radio frequency antennas disposed in an interior of the airship. One or more radio frequency transparent photovoltaic cells are disposed on an outer surface of the airship.

Abstract: A radio frequency transparent photovoltaic cell includes a back contact layer formed of an electrically conductive material, at least one aperture formed in the back contact layer, and at least one photovoltaic cell section disposed on the back contact layer. An airship includes one or more radio frequency antennas disposed in an interior of the airship. One or more radio frequency transparent photovoltaic cells are disposed on an outer surface of the airship.

Abstract: An apparatus and methods for operating a frequency selective surface are disclosed. The apparatus can be tuned to an on/off state or transmit/reflect electromagnetic energy in any frequency. The methods disclosed teach how to tune the frequency selective surface to an on/off state or transmit/reflect electromagnetic energy in any frequency.

Abstract: A tunable impedance surface capable of steering a multiband radio frequency beam in two different, independently band-wise controllable directions. The tunable surface has a ground plane and a plurality of first conductive elements disposed in a first array a first distance therefrom, the first distance being less than a wavelength of a lower frequency band of the multiband radio frequency beam. A first capacitor arrangement controllably varies capacitance between selected ones of the first conductive elements. A plurality of second conductive elements are disposed in a second array a second distance from the plurality of first conductive elements, the second distance being less than a wavelength of a higher frequency band of the multiband radio frequency beam, the plurality of first conductive elements serving as a ground plane for the plurality of second conductive elements. A second capacitor arrangement controllably varies capacitance between selected ones of the second conductive elements.

Abstract: An apparatus and methods for operating a frequency selective surface are disclosed. The apparatus can be tuned to an on/off state or transmit/reflect electromagnetic energy in any frequency. The methods disclosed teach how to tune the frequency selective surface to an on/off state or transmit/reflect electromagnetic energy in any frequency.

Abstract: An imager comprising a sphere of dielectric material and a geodesically configured substrate disposed adjacent said sphere. The geodesically configured substrate comprises a plurality of triangularly shaped elements, at least selected ones of the triangularly shaped elements having an array of detectors disposed thereon, the detectors in the array also being disposed adjacent the dielectric sphere for receiving and detecting incoming electromagnetic waves delivered via said sphere.

Abstract: Methods for tuning at least a region of a tunable frequency selective surface. The methods disclosed how to achieve an opaque or absorptive state in at least a region of tunable frequency selective surface.

Abstract: An antenna having an impedance matching section for attaching to a sheet or a garment. The antenna has a first, a second, and a third leaky substantially coaxial conductor. The first and the third coaxial conductors have an electrically conductive layer placed on the dielectric in a double helix. The second coaxial conductor has an electrically conductive layer placed on the dielectric in a single helix. The first coaxial conductor is coupled to the second coaxial conductor, the second coaxial conductor is coupled to the third coaxial conductor; and the third coaxial conductor is coupled in use to a first termination impedance. Methods to make the foregoing structures are also described.

Abstract: A radio frequency transparent photovoltaic cell includes a back contact layer formed of an electrically conductive material, at least one aperture formed in the back contact layer, and at least one photovoltaic cell section disposed on the back contact layer. An airship includes one or more radio frequency antennas disposed in an interior of the airship. One or more radio frequency transparent photovoltaic cells are disposed on an outer surface of the airship.

Abstract: A chaff element for interfering with radar signals. The chaff element has a dielectric substrate and a pair of elongate electrically conductive elements, having a total length of approximately one-half wavelength of the radar signals or otherwise tuned to the radar signals, disposed on the dielectric substrate. A switch is arranged to electrically couple the pair of elongate elements together in response to a control signal generated by an oscillator circuit and a battery. The chaff element can be used in a method of providing a countermeasure against radar signals. A plurality of chaff elements can be deployed in an airspace above a radar unit emitting a radar signal and interfere with the radar signal by opening and closing the switches of the chaff elements while deployed in said airspace above the radar unit.

Abstract: A method and system for determining an optimized artificial impedance surface is disclosed. An artificial impedance pattern is calculated on an impedance surface using an optical holographic technique given an assumed surface wave profile and a desired far field radiation pattern. Then, an actual surface wave profile produced on the impedance surface from the artificial impedance pattern, and an actual far field radiation pattern produced by the actual surface wave profile are calculated. An optimized artificial impedance pattern is then calculated by iteratively re-calculating the artificial impedance pattern from the actual surface wave profile and the desired far field radiation pattern. An artificial impedance surface is determined by mapping the optimized artificial impedance pattern onto a representation of a physical surface.

Abstract: A method for designing artificial impedance surfaces is disclosed. The method involves matching impedance component values required for a given far-field radiation pattern (determined, for example, by holographic means) with measured or simulated impedance component values for the units of a lattice of conductive structures used to create an artificial impedance surface, where the units of the lattice have varied geometry. For example, a unit could be a square conductive structure with a slice (removed or missing material) through it. The measured or simulated impedance components are determined by measuring wavevector values for test surfaces in three or more directions over any number of test surfaces, where each unit of a given test surface has the same geometric shape and proportions as all of the other units of that test surface, but each test surface has some form of variation in the unit geometry from the other test surfaces. These test measurements create a table of geometry vs.

Abstract: A reflectarray is disclosed. The reflectarray includes a first array of conductive patches supported by a substrate, wherein each conductive patch in the first array has a first center line along a Y-direction and a second centerline along an X-direction, a plurality of first variable capacitors, wherein each first variable capacitor is electrically coupled to one of the conductive patches in the first array along the first centerline, and a plurality of second variable capacitors, wherein each second variable capacitor is electrically coupled to one of the conductive patches in the first array along the second centerline.

Abstract: A method of and apparatus for modulating an optical carrier by an incident electromagnetic field. The electromagnetic field propagates in a dielectric-filled transverse electromagnetic waveguide, At least one slice of an electro-optic material is disposed in the dielectric-filled transverse electromagnetic waveguide, the electro-optic material in the dielectric-filled transverse electromagnetic waveguide having at least one optical waveguide therein which has at least a major portion thereof guiding light in a direction orthogonal with respect to a direction in which the dielectric-filled transverse electromagnetic waveguide guides the incident electromagnetic field. Light is caused to propagate in the at least one optical waveguide in the at least one slice of an electro-optic material in the dielectric-filled transverse electromagnetic waveguide for modulation by the incident electromagnetic field.

Abstract: An artificial impedance structure and a method for manufacturing same. The structure contains a dielectric layer having generally opposed first and second surfaces, a conductive layer disposed on the first surface, and a plurality of conductive structures disposed on the second surface to provide a preselected impedance profile along the second surface.