摘要:
An adaptive surface has a dielectric surface with a repeating pattern of electrically conductive structures disposed thereon or therein, the dielectric surface in combination with repeating pattern of electrically conductive structures forming a metasurface for binding surface waves thereto. A plurality of actuators on the dielectric surface alter the shape of the metasurface in response to control signals. A plurality of sensors on the dielectric surface for measuring a desired parameter and converting it to data. A plurality of rectennae disposed on the dielectric surface for providing electrical power to said actuators and to said sensors. A plurality of data antennas are disposed on or in the dielectric surface, the data antennas being coupled with data receivers and data transmitters for receiving data from an external source for controlling the actuators and for transmitting data from said sensors to an external receiver.
摘要:
A method and apparatus for creating uniform heating of an microwave absorptive target. A microwave housing has a longitudinal axis and propagates a waveguide mode at an operating frequency. The target is located in an axial cross-sectional area relative to the longitudinal axis. First layer conductive strips are layered proximal to an inner wall of the microwave housing, substantially parallel to the longitudinal axis and being separated from an adjacent first layer conductive strip by a respective first layer gap, the inner wall acting as a ground plane. Second layer conductive strips are layered proximal to the first layer of conductive strips, parallel to the longitudinal axis and being separated from an adjacent second layer conductive strip by a respective second layer gap. Each first layer gap is centered under a respective second layer conductive strip and each second layer gap is centered over a conductive layer.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
The radiation properties and wave guiding properties of frequency selective surfaces are used in conjunction with closely spaced antenna elements to fabricate antenna structures having adjustable radiation characteristics. The direction, magnitude, and polarization of radiation patterns for such antenna structures can be adjusted by varying the texture or patterning of layers of conducting material forming the frequency selective surfaces. The invention enables the fabrication of low profile antenna structures that can easily be conformed or integrated into complex surfaces without sacrificing antenna performance.
摘要:
A switch arrangement comprises a plurality of MEMS switches arranged on a substrate about a central point, each MEMS switch being disposed on a common imaginary circle centered on the central point. Additionally, and each MEMS switch is preferably spaced equidistantly along the circumference of the imaginary circle. Connections are provided for connecting a RF port of each one of the MEMS switches with the central point.
摘要:
A low-profile multi-band antenna module includes first and second antennas that transmit first and second radio frequency (RF) signals in a first and second RF band, respectively. A first RF multiplexer combines the first and second RF signals for transmission. The first antenna, second antenna, and first RF multiplexer are arranged on a panel. A transmission line communicates with the first RF multiplexer and transmits the first and second RF signals. A second RF multiplexer communicates with the transmission line and separates the first and second RF signals. At least one of the antennas communicates with an amplifier. The transmission line supplies direct current (DC) power to the amplifier. The first and second antenna are arranged on the panel in an orientation that minimizes electrical interference between the first and second antenna. A combination of the first and second antenna minimizes interference between the first and second RF band.
摘要:
A crossed-slot antenna is fabricated using rectangular sheet of metal. A crossed-slot is etched or stamped in the sheet of metal. A feed structure is similarly formed in the sheet of metal. Sidewalls are integrally formed with the sheet of metal and are bent to form a rectangular box. A circuit board is attached to the rectangular box. An air-filled cavity is defined by the sheet of metal, the sidewalls, and the circuit board. Alternatively, a crossed-slot antenna with a solid cavity is fabricated using a sheet of plastic. Ridges are formed in a cross pattern on the sheet of plastic. The sheet of plastic is plated with metal. The metal is removed from a surface of the sheet of plastic, exposing the ridges.
摘要:
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.