Abstract: A multi band antenna feed, for supporting multiple frequency bands, is coupled to a reflector and includes a cylindrical core waveguide and at least three coaxial cylinders, encircling said cylindrical core waveguide and forming at least three coaxial waveguides, bounded between pairs of consecutive coaxial cylinders. The cylindrical core waveguide and the at least three coaxial waveguides provide a pair of sum and difference radiation patterns, for each frequency band: a C-band, an S-band and an L-band.

Abstract: The invention is to a system and method for detecting materials on a conductive surface and measuring the thickness and permittvity of the material. A polarized Radio Frequency signal is reflected from a conduction surface having a material thereon. The reflected de-polarized signal is then processed to determine the thickness and permittivity of the material on the conductive surface.

Abstract: An RF antenna and an associated receiver are proximately located in an integrated antenna/receiver unit thereby eliminating the need for baluns and inter-component cabling characteristic of prior designs. Integration of the receiver with the antenna provides for improved sensitivity as the need for utilizing signal dissipating and noise introducing cables and baluns to transmit the signal received by the antenna to the receiver is eliminated. Direct coupling of the antenna and receiver on a single gallium arsenide integrated circuit maintains balanced impedance from the antenna to the receiver.

Abstract: The total energy, wave type, orientation and rotation of an incident electromagnetic signal having an unknown polarization is identified through single channel frequency domain signal analysis of the incident electromagnetic wave power as measured by an orthogonally polarized electromagnetic sensor. A controlled switch samples between the power measurements at each orthogonal output of the sensor to generate a signal comprised of a carrier frequency component and two sideband frequency components in the frequency domain. The sampled radio frequency signal is down converted by a single channel receiver to an intermediate frequency where the carrier and one sideband frequency component are separated and coherently shifted to the same frequency. A phase detector and ratiometer measure the relative phase and amplitude differences between the separated carrier and sideband frequency components to identify the wave type, orientation and rotation of the incident electromagnetic signal.

Abstract: Monolithic microwave integrated circuit (MMIC) technology is advantageously used to fabricate microwave circuitry for an antenna-converter system to enable an antenna and its associated converter circuits to be integrated together into a unitary package. Small reliable radio frequency (RF) circuits, polarization switch matrix circuits, intermediate frequency (IF) circuits and power and control circuits for the converter are manufactured and integrated onto a plurality of small area microwave circuit disks using MIC/MMIC technology. The plurality of converter circuit disks are sandwiched together and directly mounted flat against the back of the antenna to form a unitary package. The disks for the converter circuits are further sized such that the circuit disks fit within an envelope volume defined by the size and shape of the antenna.

Abstract: The wave type, orientation and rotation of an incident electromagnetic signal having an unknown polarization is identified through single channel frequency domain signal analysis of the incident electromagnetic wave power as measured by an orthogonally polarized electromagnetic sensor. A controlled switch samples between the power measurements at each orthogonal output of the sensor to generate a signal comprised of a carrier frequency component and two sideband frequency components in the frequency domain. The sampled radio frequency signal is down converted by a single channel receiver to an intermediate frequency where the carrier and one sideband frequency component are separated and coherently shifted to the same frequency. A phase detector and ratiometer measure the relative phase and amplitude differences between the separated carrier and sideband frequency components to identify the wave type, orientation and rotation of the incident electromagnetic signal.

Abstract: A multi-element antenna formed of symmetrical paired elements symmetrically positioned in a concentric arrangement. The proximate ends of the elements are interconnected through a switching network which, when properly biased, permits exciting the element of the antenna to obtain right-hand or left-hand circularly polarized radiation.