Abstract: A communication system 10 for providing uninterrupted radio operation, including: a pre-transmitter system 12 comprising: (i) a first buffer 14 for storing a sequence of digital audio samples from an audio source 16, the first buffer 14 having a beginning 18, an end 20 and a length 22; (ii) storing means 24 for storing the audio samples in the first buffer 14 in shift register configuration format; and (iii) frame construction means 26 for constructing a data frame including a first audio sample from the end 20 of the first buffer 14 and a second audio sample from the beginning 18 of the first buffer 14; wherein the data frame can be transmitted and received.

Abstract: A technique for detecting and verifying a fingerprint includes a skin resistance sensing array for translating the skin resistance of a fingertip into an electrical signal. The fingertip is moved relative to the skin resistance sensing array in a first linear direction for producing a reference trajectory signal which is stored into a memory. The fingertip is again moved relative to the skin resistance sensing array in a second linear direction for producing a sample trajectory signal. The second linear direction of movement is offset from the first linear direction of movement by a predetermined angle. A processor is provided for performing a set of functions on the reference trajectory signal and the sample trajectory signal. The sample trajectory signal is correlated with the reference trajectory signal for producing a verification signal related to the probability that the fingertip generated both the sample trajectory signal and the reference trajectory signal.

Abstract: In accordance with the teachings of the present invention, a telescoping deployable mesh antenna reflector for space communication applications and a method of deployment is provided. The antenna reflector includes a plurality of telescoping radially extending ribs between which a plurality of interconnected guylines are secured to form a wire truss structure. The telescoping radially extending ribs include pivotally coupled inner and outer ribs that are collapsed and folded to stow the antenna. A highly reflective wire woven mesh is connected to the front surface of the wire truss structure with flexible radially extending strip members allowing for folding and telescoping of the antenna reflector.

Abstract: A standby power supply dedicated to a peripheral electronics apparatus on aircraft provides an isolated ungrounded self-contained source of DC operating voltage. That source is applied to the electronics apparatus upon indication of turbine generator shut-down or failure before the voltage generated by the turbine generator completely falls off. Formed with an EMI filter, a fast pulse mode battery charger, a lead-acid battery pack, a DC to DC converter, and a pair of electromagnetic relays, the standby power supply ensures that the electronic apparatus is never without operating power even momentarily.

Abstract: A SQUID 10 was multiple junctions, each junction allowing a critical current to flow therethrough. The SQUID 10 comprises a laminar structure including: (a) a substantially planar substrate 12; (b) a first high temperature superconductive layer 14 of substantially uniform thickness deposited on the substrates; (c) a dielectric layer 16 deposited on the first superconductive layer 14, the dielectric layer 16 comprising a planar level segment 18 having two ramp segments defining SQUID junctions at opposing ends 20 and defining SQUID hole; and (d) a second high temperature superconductive layer 24 of substantially uniform thickness deposited on the dielectric layer 16, the second high temperature superconductive layer 24 covering all three segments of the dielectric layer 16.

Abstract: There is provided an apparatus 10 for transceiving millimeter electromagnetic waves (MEW) creating a high resolution image of a field of view sensed by a flexibly resilient tapered slot antenna 12 formed with a resonant cavity 18 and a transformer horn 19; the antenna is affixed to solenoid unit 20 for imparting a vibratory force to the antenna causing it to scan a field of view. There is provided an integrated circuit signal processor chip 32 and a MEW signal affixed to the antenna 12. A 2 D amplitude modulator 34 is affixed to the leading edge of the antenna 12 adjacent the transformer horn 19 to impart orthogonality to the MEW signal that is transceived in order to achieve a 2 D azimuthal scan. The sensed signal is matched in the processor 32 which has input a template of an orthogonally power distributed beam by auto-correlation to the template.

Abstract: The problem of reducing the size of a dual offset Cassegrain reflector type microwave antenna without adversely affecting performance while retaining the simplicity of the main reflector's (1) and subreflector's (3) traditional simple surface curvatures is solved by having the paraboloidal shaped main reflector's focal length, fm, and diameter, D, fulfil the criteria that the ratio of fm to D is less than 1.0; and in which the hyperboloidal shaped subreflector (3) is oriented so that its left foci, at which the microwave feed (5) aperture is placed, lies above the main reflector's focal axis. It's subreflector subtends an angular arc about the focal point that is slightly larger than the corresponding arc subtended by the main reflector. The elegance of the compact antenna is demonstrated by improved performance, attaining efficiencies in excess of seventy three percent.

Abstract: An omnidirectional isotropic antenna employing a tubular waveguide 12, a dielectric insert 18 which includes a lens 20 and a depending stem 22. The lens 20 is an elliptoid generated by rotating an elliptoid form about the longitudinal axis 42 of the tubular waveguide 12 with its foci 40 aligned with the longitudinal axis 42 and its major axis 38 lying in a zone of rotation 43 intersecting the horizontal plane 44 that is normal to the axis 42 and containing the foci 40. The stem 22 has integrally formed a polarizing element 36, and an impedance to matching element 21. There is provided a passband filter 50 and a modified tubular waveguide 60 that provides node differences for the RF signals.

Abstract: A system for preparing excited molecular oxygen in the excited singlet-delta electronic state for use in a chemical laser that minimizes salt formation utilizing the common ion effect. In one version, basic hydrogen peroxide is formed by combining H.sub.2 O.sub.2 and at least two bases. In another version of the invention, the basic hydrogen peroxide is reacted with a gas containing at least two halogen species.

Abstract: A precision deployable boom assembly 10 for terrestrial and celestial applications comprises an extendable and retractable boom 12 having a fixed end 14, a movable distal end 20 and three or more cables 30 attached to the distal end to form a tripod configuration of the deployed boom. The boom is spring biased to urge extension of the boom and to produce a tensile pre-load in the cables. The cables are wound and unwound by cable drums 28 selectively driven by precise motors such as stepping motors 33. The cables are preferably formed of graphite which provides high stiffness, light weight and a very low coefficient of thermal expansion. The position of the distal end is highly stable at all deployed lengths of the boom and is also precisely repeatable.

Abstract: The invention relates to a method for fabricating III-V semiconductor micro-optical lenses for hybrid integration with micro-optical devices, where a micro-optical lens is formed from a semiconductor wafer by selectively etching a surface of the semiconductor wafer and a lens arm is formed from the semiconductor wafer on a surface opposite the surface by selectively etching the surface of the semiconductor wafer. The lens and lens arm are then cleaved from the substrate wafer and directly mounted to a micro-optical device. As a result of using III-V semiconductor material to form micro-optical lenses for hybrid integration to micro-optical devices of the same semiconductor material, thermal expansion stability is increased and efficient transfer of light between micro-optical lenses and micro-optical devices is achieved.

Abstract: A weighted interleaving system (10) is used for correlated channel coding. The weighted interleaving system (10) includes a weighted interleaver (12) having a pseudo-random demultiplexer (18), a first branch (28), a second branch (30), a third branch (32) and a pseudo-random multiplexer (38). The pseudo-random demultiplexer (18) receives input data bits at an input (20) and randomly distributes the input data bits to first (22), second (24) and third (26) outputs of the pseudo-random demultiplexer (18). The first branch (28) in communication with the first output (22) delays the transmission of the input data bits routed to it by a minimum delay. The second branch (30) in communication with the second output (24) delays the transmission of the input data bits routed to it by a delay uniform in probability from the minimum delay to a maximum delay. The third branch (34) in communication with the third output (26) delays the transmission of the input data bits routed to it by the maximum delay.

Abstract: A True Time Delay system for creating variable time delays of an optical signal suitable for use with a phased array antenna system in order to avoid beam-squint in broadband applications. The TTD is adapted to be integrated on a planar silica waveguide in order to substantially reduce the package size of the device. In one embodiment of the invention, the TTD is formed from a polarization beam splitter, a polarization rotator and a spiral waveguide. In an alternate embodiment of the invention, the TTD includes a polarization sensitive Mach Zehnder interferometer, a quarter wave polarization rotator and a spiral waveguide. In both embodiments of the invention Bragg reflective gratings are written into the spiral waveguide at different spacings to reflect optical signals of different wavelengths to create various time delays.

Abstract: A rotating mirror drum radiometer imaging apparatus. The apparatus generally comprises a two-sided mirror, a drum for securely supporting the two-sided mirror therein at an angle of preferably about 45 degrees relative to a longitudinal axis of symmetry extending through the drum, support walls for supporting the drum for rotational movement, and a motor and drive wheel for rotationally driving the drum. In one embodiment the drum includes first and second cut-outs in a side surface thereof. The cut-outs are further spaced preferably about 180 degrees from each other about the longitudinal axis of symmetry and enable a transmitted signal to be alternately received therethrough by first and second sides of the two-sided mirror as the drum and mirror are concurrently rotated by the motor and drive wheel. A first antenna is disposed adjacent a first end of the drum and a second antenna is disposed adjacent a second end of the drum.

Abstract: A lanthanum aluminate (LaAlO.sub.3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO.sub.3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also be used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.

Abstract: The invention pertains to a digital video horizontal synchronization pulse detector and processor comprising pulse detector for generating a timing pulse in response to each horizontal synchronization pulse. A sync position error device generates a time position error signal for each timing pulse relative to a corresponding window pulse. A window pulse generator generates the window pulses and limits the time position error signals to a maximum value. An acquisition device tracks when the timing pulses occur inside and outside the corresponding window pulses. An averaging device averages the time position error signals to generate an average error signal.

Abstract: A method is provided for determining the geolocation of a mobile terminal within a telecommunications satellite system. The system supports first and second forward communications links from first and second earth stations through first and second satellites to a common mobile terminal. The method includes receiving, at the mobile terminal, first and second forward link communications signals from the first and second earth stations and, based thereon, obtaining synchronization differential data. The synchronization differential data may include timing and frequency synchronization data necessary to maintain synchronization between the first and second communications at the mobile terminal. The mobile terminal transmits the synchronization differential data to the first earth station over the return link. The first earth station receives communications signals from the mobile terminal and based thereon calculates return link synchronization data.

Abstract: A sensor having an interferometer, and a corresponding method, for use in the sensing of focal shifts in high energy laser beams are provided. The interferometer includes optical elements for generating a reference beam with a known wavefront phase curvature. In a preferred form of the invention, the reference beam is dithered and recombined with a sample beam, to produce a time-varying interference pattern indicative of the focal shift in the high energy laser beam. The interference pattern is focused by a lens onto a detector that produces electrical signals indicative of the detected interference pattern. The electrical signals are synchronously detected to remove the dither-frequency component, integrated, and amplified to generate a focal shift correction signal. The focal shift correction signal is then applied to an axially adjustable lens positioned to effect phase curvature changes in the reference beam wavefront to match those of the sample beam.

Abstract: A heterojunction bipolar transistor with a vertically integrated profile includes a substrate layer, a collector contact layer, a collector layer, a base layer and an emitter layer, formed from AlGaAs, etched to form an emitter mesa leaving a relatively thin passivating layer, adjacent the emitter mesa. The base metal contacts are formed on the passivating layer, resulting in a wider bandgap, thus minimizing surface recombination velocity at the emitter-base junction and increasing the overall gain (.beta.) of the device. The base metal contacts are formed by evaporating a p-ohmic metal onto the n-type passivation layer. The p-ohmic contacts are annealed, resulting in p-type metal diffusion through the passivating layer and reaction with the base layer, resulting in ohmic contacts.

Abstract: The present invention provides a solid state laser gain medium 28 comprising: (a) a gain layer 30 having pump regions 32 and first and second contact regions 34 and 36, respectively; (b) a first transparent layer 38 optically connected to the first contact region 34 of the gain layer 30 by diffusion bonding; and (c) a second transparent layer 40 optically connected to the second contact region 36 of the gain layer 30 by diffusion bonding. The transparent layers 38 and 40 are transparent to the lasing wavelength of the gain medium 28.