Abstract: An improved plasma vessel (i.e., plasma applicator) that provides effective cooling includes a plurality of generally linear tubes having a dielectric interior fluidly connected together by dielectric connectors. The tubes and connectors are joined together to form a leak-tight plasma vessel. A cooling system surrounding the improved plasma vessel includes a rigid cooling plate and a deformable thermal transfer material disposed between the plasma vessel and the cooling plate. After use or at an operator's discretion, the plasma vessel can be removed from the cooling system and a new vessel may be inserted in its place. Alternatively, the used vessel may be refurbished and re-inserted into the cooling system. The new or refurbished vessel may or may not be of the same size or configuration as the used vessel. Thermal contact between the cooling system and the new or refurbished vessel, however is maintained through the deformable thermal transfer material.

Abstract: A method for controlling pulsed power that includes measuring a first pulse of power from a power amplifier to obtain data. The method also includes generating a first signal to adjust a second pulse of delivered power, the first signal correlated to the data to minimize a power difference between a power set point and a substantially stable portion of the second pulse. The method also includes generating a second signal to adjust the second pulse of delivered power, the second signal correlated to the data to minimize an amplitude difference between a peak of the second pulse and the substantially stable portion of the second pulse.

Abstract: Apparatus and method for self-contained calibration and failure detection in a phased array antenna having a beamforming network. The beamforming network includes a plurality of array ports and a plurality of beam ports or a space fed system. A plurality of antenna elements and a plurality of transmit/receive modules are included. Each one of the modules is coupled between a corresponding one of the antenna elements and a corresponding one of the array ports. A calibration system is provided having: an RF input port; an RF detector port; an RF detector coupled to the RF detector port; and an antenna element port. A switch section is included for sequentially coupling each one of the antenna elements through the beam forming/space-fed network and the one of the transmit/receive modules coupled thereto selectively to either: (a) the detector port during a receive calibration mode; or, (b) to the RF input port during a transmit calibration mode.

Abstract: Failure detection in a phased array antenna system is accomplished using a cluster-oriented detection scheme and a mutual coupling test signal injection technique. RF BITE TRM (110) is connected to an RF BITE port (120) on an illuminating means (140). Illuminating means (140) provides a uniform input signal level to many TRMs (150). Each TRM (150) is connected to an antenna element (210). Controller (170) causes one element (220) in a cluster to operate in a transmit mode and causes other elements (230) to operate in a receive mode. Internal detectors in TRMs (150) are used to detect signal levels, and these detected signal levels are used to identify failure modes. This cluster search method operates well for many types of phased arrays including rectangular and triangular lattices, planar and conformal apertures, single frequency and shared aperture types.

Abstract: A Doherty-type power amplifier suitable for satellite telecommunication systems provides linear amplification of noise-like RF signals that have multiple carriers spread over a large instantaneous bandwidth. Efficiencies of 40% to 50% are achieved using PHEMT devices. The power amplifier includes a carrier amplifier that operates a low power levels and a peak amplifier that operates at high power levels. For low power levels, the carrier amplifier delivers its output into twice the optimum load resulting in high efficiency, while the peak amplifier is turned off. At high power levels, both the carrier and the peak amplifier is working into an optimum load and maximum power is delivered. Output matching sections are used to transform the very low optimum load impedance of the PHEMT devices prior to phase shifting and combining.

Abstract: A lightweight patch radiator phased array antenna having a single layer patch construction on an artificial dielectric, such as syntactic foam, which achieves a factor-of-ten weight savings over an array constructed with conventional materials. An additional sixty-five percent weight reduction is achieved by cutting away the dielectric material down to the array antenna's ground plane everywhere except under the patch radiator. This construction allows placement of a thermal control material over the patch and ground plane for space applications.

Abstract: A low array antenna having transmit/receive (T/R) modules, which contain a digitally-controlled variable attenuator, for each of the two polarizations (horizontal and vertical). The array has a cylindrically curved surface which closely conforms to the shape of the fuselage of an airborne vehicle or another structure. Each polarization feeds into an elevation beamformer apparatus which provides both a uniform taper and a Bayliss/Taylor taper. As the beam is scanned in elevation, the amplitude taper is adjusted via the variable attenuator to control the taper of a sum pattern and thereby achieve low sidelobe far field sum patterns. The same attenuators that are used for the sum pattern also feed a difference network. The T/R module attenuators are set to yield the desired low sidelobe sum illumination for a desired elevation scan angle.

Abstract: A radar type center fed antenna comprising a small radiating horn supported at the focal point of a parabolic reflector by three struts which are oriented to minimize the parallel polarization scattering and which have a low scattering ogive cross-section. The horn is mounted at the vertex of the parabolic surface and the intersection of the three struts using a bracket that provides minimal blockage. The struts are attached to the perimeter of the reflector. One strut having a feed waveguide is attached to the top-center of the reflector and the other two are attached at points on either side of the bottom-center at thirty degree angles to the vertical plane. The strut shape and feed-horn supporting and attaching arrangement and the integration of the feed waveguide into one of the struts results in a very low sidelobe antenna that produces a far-field pattern that has very low forward scattering due to feed and strut blockage.

Abstract: A low-profile patch radiator for use in an array antenna has a multilayer structure which includes a double-tuned impedance matching network and balun and a coaxial feed for linear polarization of the radiated waves. A second embodiment further includes a second double-tuned impedance matching network and balun and a second coaxial feed for dual polarization operation. The matching networks/baluns, which comprise microstrip circuits on Duroid substrates, increase the frequency bandwidth of the patch radiator.

Abstract: A space fed antenna system is adapted to correct for beam pointing (squint) errors and collimation errors caused by frequency variations of the R.F. energy radiated by the antenna system. A subarray of radiating elements is spatially positioned between an electronic lens and the focal point of said lens. The subarray radiates R.F. energy with a spherical wavefront for illuminating the electronic lens, such spherical wavefront having a focal point coincident with the focal point of the electronic lens. A programmer is provided which controls the electronic lens to collimate and direct the R.F. energy from the subarray. A corporate feed is provided which couples to a plurality of phase shifters which feeds corresponding time delay units, which in turn feeds corresponding radiating elements in the subarray. The phase shifters, responsive to the programmer, provide the spherical wavefront to the R.F. energy radiated by radiating elements in the subarray.

Abstract: This invention provides different length glass fibers for providing a broad range of optical time delays for short incident chromatic light pulses for the selective spatial and frequency analysis of the light with a single light detector. To this end, the frequencies of the incident light are orientated and matched with the different length fibers by dispersing the separate frequencies in space according to the respective fiber locations and lengths at the input terminal of the glass fibers. This makes the different length fibers useful in the field of plasma physics. To this end the short light pulses can be scattered by a plasma and then passed through the fibers for analyzing and diagnosing the plasma while it varies rapidly with time.