Abstract: A field emission display having a plurality of pixels is disclosed wherein each pixel includes a cathode with a plurality of field emitters and corresponding gate electrodes to emit electrons, an anode distally disposed with respect to the cathode, the anode and the cathode capable of having a voltage difference greater than 6000 volts, and a focus grid disposed between the anode and the cathode, the focus grid having an aperture and disposed in proximity with the cathode to focus electrons from the plurality of field emitters of the cathode toward the anode. With such an arrangement, a field emission display is provided having greater brightness and efficiency.

Abstract: Charge coupled shift registers for sonar beamforming provide many channels of high resolution large delays by the cascading of two registers. Two equivalent embodiments are disclosed. In one embodiment the shift rate of the input shift register is an integer multiple "m" of the shift rate of the output shift register which is responsive to every m th signal presented to it. The other embodiment samples the signal in the input register by selected m th pulses of a pulse train whose frequency is m times the shift frequency of the output register. Each embodiment preserves the higher resolution phase information and incremental delay of the higher frequency sampling of the input shift register. The long time delay is provided by the output shift register operating at the lower shift rate.

Abstract: A DC to DC, fixed frequency, Buck family power converter having a first feedback control loop for regulating output current or output voltage depending on the operational mode selected, a second feedback control loop for current mode control and a third feedback control loop for providing improved dynamic response for all conditions of line and load. The third feedback control loop senses the output voltage and generates a variable ramp signal having a slope (M) which is proportional to the converter output voltage. By maintaining as a constant (K) a ratio of the variable ramp slope (M) to the falling slope (M.sub.2) of a voltage representation of the inductor current in an LC network of the Buck regulator or K=M/M.sub.2, improved dynamic operation of the power converter results for a plurality of output voltages particularly improving output ripple rejection and minimizing effects of injected noise in the current mode control loop.

Abstract: A narrow band receiver is shown to include a double downconversion arrangement wherein the frequency of the second local oscillator is controlled to maintain the frequency of the second I.F. signals at a predetermined value.

Abstract: An antenna system is described including a reflector antenna, responsive to radio frequency signals at a first frequency, having a first reflector surface, a second reflector surface and a Cassegrain feed. The antenna system further includes an array antenna having a plurality of antenna elements responsive to radio frequency signals having a second different frequency, wherein a center element is in a common location with the feed of the reflector antenna. With such an arrangement, an improved dual band antenna system is provided. By providing the center element of the array antenna in a common location with the feed of the reflector antenna, a dual band radio frequency antenna system is provided which is more compact with improved radiation characteristics than known similar configured antennas.

Abstract: A field effect transistor including a substrate comprised of a material having a spinel crystal structure and a buffer layer lattice matched to the crystal structure of the substrate comprising gallium aluminum indium arsenide is described. Several types of field effect transistors are possible with the described substrate arrangement, including metal semiconductor field effect transistors, insulating gate field effect transistors, pseudomorphically strained and pseudomorphically strain compensated metal semiconductor field effect transistors, as well as, high electron mobility transistor structures.

Abstract: A method of patterning a film of PZT material comprises the steps of providing a mask over a selected surface portion of the PZT material; and, plasma etching unmasked portions of the thin film material. The method includes the steps of: introducing a gas mixture of halogenated gases into a chamber; ionizing the gas mixture into a plasma in the chamber by imposition of an electric field across the introduced gaseous mixture, chemically reacting the ionized gaseous mixture, chemically reacting the unmasked portions of the lead zirconate titanate thin film material to selectively remove such exposed portion of the thin film material. The gas mixture is a mixture of a chloride and a compound of fluorine. Preferably the compound of fluorine is a halocarbon or fluorocarbon. In particular, the fluorocarbon is a trifluoromethane, CHF.sub.3, and the chloride is boron trichloride BCl.sub.3.

Abstract: An infrared detector array having a plurality of infrared detectors arranged in a matrix of rows and columns in a first semiconductor body; and, a plurality of integration/read circuits arranged in a matrix of rows and columns in a second semiconductor body, each one of the plurality of integration/read circuits being in vertical registration with, and electrically connected to, a corresponding one of the plurality of detectors. Each one of the integration/read circuits includes: a capacitor; a first transistor, electrically coupling the capacitor and the corresponding one of the detectors during an integration mode, for enabling current generated in the detector in response to impinging radiation to pass from the detector to the capacitor for integration; and a second transistor, electrically coupling the charge built-up on the capacitor during the integration mode to an output bus during a subsequent read mode.

Abstract: A data communication system comprising a plurality of fiber optic cables and a fiber optic switching system, comprising: a support structure for securing light emitting/light receiving ends of the plurality of fiber optic cables in predetermined positions; and, means for re-directing light emitted from the light emitting/light receiving end of one of the fiber optic cables to the light emitting/light receiving end to the light emitting/light receiving end of another one of the plurality of fiber optic cables. The re-directing means includes means for collimating and directing the light emitted from the end of one of the cables as a beam propagating along a predetermined direction and for re-directing the beam towards the end of another one of the cables selectively in accordance with an electrical signal. More particularly, the re-directing means includes electro-optical phase shifting medium, preferably liquid crystal molecules.

Abstract: A transducer having an energy conversion medium for converting changes in applied mechanical energy into corresponding changes in thermal energy and a pyroelectric material in thermal energy transfer relationship with the energy conversion medium for producing an electrical output substantially in response to the converted thermal energy. Such transducer is particularly useful as a hydrophone in detecting low frequency sound waves emitted by, or reflected from, underwater objects.

Abstract: A sonar system is provided for identifying a foreign object includes a technique for providing a two dimensional array of pixels, each one of the pixels representing the intensity of a signal at a predetermined range position and a predetermined cross-range position from a reference position and quantizing the intensity of each one of the pixels into one of a plurality of levels. The technique further includes comparing a distribution of the levels of pixels over a range scan at a cross-range position with the distribution of levels of pixels over a range scan at a different cross-range position to identify the existence of a foreign object. With such an arrangement a sonar system is provided that can automatically detect the existence of a foreign object such as a mine.

Abstract: A synthetic aperture radar guidance system adapted for use in a guided missile is described wherein the frequency of the transmitted pulses changes with time with a chirp slope which varies with range. The time between pulses also changes as a function of range. The desired values of the chirp slope and the interpulse interval are computed for all values within a range of interest and stored. Furthermore, the operating parameters of the SAR are changed as the range changes. The time intervals and frequencies are selected to avoid interruption ambiguities and eclipsing. The phase and frequency of the synthesized signal are controlled to adjust for motion of a vehicle on which the SAR is mounted. The SAR is operated in several modes. In a search mode, the beam of transmitted pulses is steered across a mapping area to form a plurality of patches of the mapping area. The patches are combined into one map of the entire area. Each pixel of the map is compared with a target template until a match is provided.

Abstract: A spinning projectile is described including a roll rate sensor for providing a spin frequency signal, a nutation frequency signal and a precession frequency signal and a seeker for providing a boresight angle signal. The spinning projectile further includes a torquer assembly, responsive to a control signal, for selectively providing a force in a desired lateral direction and a digital signal processor, responsive to the spin frequency signal, the nutation frequency signal, the precession frequency signal and the boresight angle signal, for providing a control signal to the torquer assembly to control the desired direction of the force. With such an arrangement, a projectile is provided having greater maneuverability wherein an increase in maneuver footprint is obtained by having the maneuver force equal the sum of the rocket force and the body force rather than being a difference as in known projectiles.

Abstract: A synthetic aperture radar guidance system adapted for use in a guided missile is described wherein the frequency of the transmitted pulses changes with time with a chirp slope which varies with range. The time between pulses also changes as a function of range. The desired values of the chirp slope and the interpulse interval are computed for all values within a range of interest and stored. Furthermore, the operating parameters of the SAR are changed as the range changes. The time intervals and frequencies are selected to avoid interruption ambiguities and eclipsing. The phase and frequency of the synthesized signal are controlled to adjust for motion of a vehicle on which the SAR is mounted. The SAR is operated in several modes. In a search mode, the beam of transmitted pulses is steered across a mapping area to form a plurality of patches of the mapping area. The patches are combined into one map of the entire area. Each pixel of the map is compared with a target template until a match is provided.

Abstract: A monitoring system is shown to include a connector, having an input path and a current return path, for connecting a two section wrist strap to said connector, said two section wrist strap, when affixed to an operator's wrist, would complete an electrical path between the input path and the current return path of the connector across the wrist skin surface. The monitoring system further includes a current source for providing an electrical current to the input path and a comparator for comparing a voltage at the input path to a high limit value and a low limit value and for providing an alarm signal whenever the voltage at the input path is not between the high limit value and the low limit value. With such an arrangement, an operator is ensured that a proper connection between the operator and ground is maintained thus significantly reducing the possibility of an electrostatic discharge harming an electronic component handled by the operator.

Abstract: A SAW oscillator circuit including a housing having disposed therein a surface wave propagation supporting substrate with a pair of transducers coupled by surface waves propagating through the substrate and electronic circuitry connected to the pair of transducers and arranged to provide, with the connected resonator, the SAW oscillator circuit. A weight is attached to the resonator. The housing is susceptible of vibratory deflections which induce vibratory deflections in the substrate and the weight suppresses the vibratory deflections induced in the substrate of the resonator. With such arrangement, while sufficiently thick externally mounted stiffeners are not used because of space limitations, the effects of vibratory deflections induced in the substrate of the insufficiently thick, or un-stiffened housing are compensated by the weight attached to the resonator.

Abstract: An antenna is described including a dielectric substrate having a first and second surface and a first sheet of conductive material disposed on the first surface of the first dielectric substrate, the first sheet of conductive material having a plurality of apertures. The antenna further includes a plurality of patch radiator elements disposed adjacent the second surface of the dielectric substrate, each one of the plurality of patch radiator elements disposed diametrically opposed a corresponding one of the plurality of apertures. With such an arrangement, an antenna is provided having broader bandwidth but less feedline radiation.

Abstract: An antenna is described including strip conductor circuitry for interconnecting a plurality of patch radiator elements to a common feed. The strip conductor circuitry includes a plurality of four port quadrature couplers having an isolation port. The antenna further includes a plurality of radio frequency terminating loads and a technique for capacitively coupling one of the plurality of radio frequency terminating loads to the isolation port of a corresponding one of the plurality of four port quadrature couplers of the strip conductor circuitry. With such an arrangement, a least expensive antenna is provided which can survive a high temperature environment.

Abstract: An optical system is described including an array of photodetectors, each photodetector having a surface, and a focusing system employing a liquid crystal phased array for focusing a beam of electromagnetic energy on the surface of at least one of the photodetectors. The focusing system further includes a focus-defocus technique for periodically defocusing the beam of electromagnetic energy on the surface of at least one of the photodetectors. With such an arrangement, a focusing system is provided wherein fixed pattern noise can be decreased.

Abstract: An integrated circuit having a semiconductor layer having formed therein a electronic circuit. An electrical device, electrically connected to the electronic circuit, has a corrugated platform supported over, displaced from, and integrally formed with, the substrate. In a preferred embodiment the electrical device is a bolometer and the electronic circuit is a read out circuit for the device. The platform includes a surface member and a leg, a proximate end of the leg being disposed on the substrate and the distal end being elevated from the substrate and terminating at the surface member. Preferably the leg and the surface member are corrugated. The supporting surface has a corrugation parallel with the leg. The surface member is supported, as a corrugated air-bridge, over the surface of the substrate by corrugated legs. The temperature sensitive resistive material is formed over the corrugated surface member.