Abstract: An air cooled, flash lamp pumped, solid state laser device wherein heating devices are disposed on the laser rod at both ends to heat and temperature stabilize the laser rod. The solid state, laser rod is longer than the arc length of the flash lamp. The ends of the laser rod can be heated directly by winding heating wire, such as Nichrome, around each end or by applying heat through thermal conductive supports. A feedback loop is provided to maintain temperature of the solid state laser rod, which is preferably Alexandrite, within a desired range of 80.degree. C. to 120.degree. C.

Abstract: A head support assembly is disclosed which may be worn continuously whenever it may be desirable to mount optical equipment, such as night vision goggles, on the head of a person. The head support assembly includes a main head piece which has a relatively rigid portion in the front and more flexible side and top pieces for fitting to a variety of head shapes. Webbing members connect the head piece to a chin piece and are of adjustable nature to provide strong securement to the wearer's head while permitting adjustment.

Abstract: A bi-directional converter offers power conversion between both 270 volts to 28 volts and 28 volts to 270 volts. The converter utilizes common magnetic components such as a transformer and a filter inductor and dual function built/in diodes across transistors. The converter also utilizes a bridge converter, a push-pull converter, and a boost converter.

Abstract: A two dimensional distributed amplifier phase shifter having a distributed reference amplifier circuit generating a reference signal, the reference amplifier circuit having its input connected to one end of a plurality of serially connected microstrip transmission lines. The phase shifter further has a plurality of phase shifted amplifier circuits, one associated with each of the microstrip transmission lines. Each phase shifted amplifier circuit has an input connected to an end of its associated microstrip transmission line which is opposite the reference amplifier circuit and generates an output signal, phase shifted from the reference signal or the output signal of an adjacent phase shifted amplifier by a predetermined phase angle. The phase shifter may be fabricated as a monolithic microwave integrated circuit.

Abstract: Display apparatus and method having window shade heating. The display has an active matrix LCD with a plurality of elements and a backlight having a variable brightness. During warm-up of the display, the operating temperature will be below the normal operating temperature. To decrease warm-up time, the LCD elements are darkened and the brightness of the backlight is increased.

Abstract: An audio system for use with a mobile radio. More particularly, a microprocessor controlled audio system capable accepting multiple audio input signals and providing an amplified audio signal to a local speaker and a remote speaker without the use of transformers or relays, and capable of driving the speakers either individually or simultaneously. The system provides for increased versatility in output configurations, and allows for microprocessor-controlled muting and power output level switching.

Abstract: A method for fabricating an all silicon absolute pressure sensor employing silicon-on-insulator structures. More particularly, a method for fabricating an all silicon absolute pressure sensor based upon an ungated metal-oxide semiconductor field-effect transistor which offers a high degree of immunity to temperature effects, increased reliability, minimal substrate parasitics, reduced manufacturing variations from device to device, as well as inexpensive and simple fabrication.

Abstract: The frequency of a variable frequency oscillator in a pulsed radar is adjusted using samples of an IF signal. An initial frequency adjustment is made using a sample taken during RF transmission. This initial adjustment contains an inaccuracy introduced by the magnetron's activity. An additional adjustment is made using temperature dependent values stored in a memory. Yet another adjustment is made during the radar's receive time using signals reflected by targets.

Abstract: A serial binary multiplier receives a multiplicand and a multiplier, and produces a product. The multiplicand is received in a serial format beginning with a most significant bit and ending with a least significant bit. The multiplier is received in a parallel format, and the product is available in both serial and parallel formats. The multiplier consists of a multiples generator, an arithmetic unit, and a decoder. The multiples generator generates a multiple of the multiplicand for each bit of the multiplier that is equal to logic one. The multiples generator produces the multiples in a serial format beginning with a most significant bit and ending with a least significant bit. The arithmetic unit serially receives the multiples produced by the multiples generator, and produces the sum of the multiples. The sum is produced in the form of two serial binary numbers which compose an unsigned redundant binary number. The decoder receives the unsigned redundant binary number produced by the arithmetic unit.

Abstract: A processing system using a number of distributed associative (content addressable) memory modules each connected through a sending device to a common serial communication bus. The memory modules are custom designed to unload stored data to a central receiver using a content induced transaction overlap (CITO) transmission.

Abstract: A multiple synchronized agile pulse generator is configured as high speed digital/analog test apparatus for providing complex patterns associated with modern avionics systems. The multiple synchronized agile pulse generator includes a network of counters and random access memory (RAM) banks which allow for predetermined hopping of pulse repetition intervals, pulse widths, pulse patterns, pulse amplitudes, and combinations of the above.

Abstract: A system for demodulating and decoding differential phase shift keying (DPSK) transmissions utilizes a bandpass filter, an analog to digital converter and a digital signal processor. Removal of the effects of unknown frequency component is achieved by applying a complex phase correction/rotation factor after DPSK demodulation. The actual phase of the complex signal is never computed directly. All of the processing from Rader decomposition through carrier tracking filter is performed on the complex values and therefore requires only multiplication and addition operations which can be performed at high speed in a microcomputer or in dedicated arithmetic hardware.

Abstract: A high-voltage, low-volume capacitor module, having a minimal amount of inherent stray inductance, and being configured so as to allow its integration into an electrical system in a manner which minimizes any stray inductance introduced by interconnection wiring. This is accomplished by integrating the capacitor into the bus bars of the voltage convertor, thereby eliminating the need for separate interconnecting wiring and reducing the overall amount of stray inductance evident within the system in which the capacitor is employed.

Abstract: A pulse-width modulated, bi-directional DC-to-DC voltage converter having a regulated output, and capable of converting between a high-potential direct current voltage and a low-potential direct current voltage. The converter's magnetic components, as well as several of its semiconductor rectifiers, perform dual functions (one in the step-up mode, and another in the step-down mode), which serves to minimize the total component count, and allows the converter to be both compact and lightweight.

Abstract: A proportional base drive circuit for a power transistor. A first MOSFET, when enabled by an ON pulse, initially supplies the base drive current from a power supply to the base of the power transistor. The resulting current flow through the transistor to a load causes a proportional current to be induced in a current transformer. The induced current is supplied to the base of the power transistor through the first MOSFET. When an OFF pulse is applied, the first MOSFET is disabled and supplies no current to the base of the transistor. At the same time a second MOSFET causes the base-emitter junction of the power transistor to be negatively biased, thereby quickly switching the power transistor off.

Abstract: In a ring laser gyroscope a laser beam is directed to travel in a closed path, however, temperature variations can cause a change in the path length which, if not corrected, can result in drift and scale factor errors. The present invention controls the length of this closed path or cavity by applying a force to the gyro normal to the lasing plane. This is accomplished by inserting a bolt through the longitude axis of the gyro and by utilizing the bolt to apply or to relieve force therefore maintaining the cavity length constant over a given temperature range.

Abstract: In a Microwave Landing System (MLS) transmitting landing guidance signals and data signals according to a time division multiplex signal format, a method and means for replacing faulty primary equipment with standby equipment. Redundant electronics units are provided for generating guidance and data signals. Transfer control means connect alternate ones of the electronics units to the appropriate antenna of the system such that no two consecutive transmissions of the same guidance or data signal is made by the same electronics unit. The signals transmitted by the system are monitored for accuracy and conformity to the signal format. If a fault is detected in a monitored signal, the electronics unit responsible for generating the faulty signal is no longer used and system operation continues with non-faulty units, unless the faulty detected indicates antenna misalignment. If antenna misalignment occurs, system operations are halted.

Abstract: A snubber circuit for a neutral clamped power inverter. The power inverter includes power transistors, a current sensor at the inverter output and a neutral clamping circuit connected between the inverter output and a neutral point in a DC power source which supplies the inverter. A controller circuit is connected to the current sensor, to the power transistors and to the neutral clamping circuit to selectively enable and disable the power transistors and the neutral clamping circuit in accordance with the inverter operation and current direction at the inverter output to minimize current transients at a load. An active snubber arrangement is provided to minimize snubber losses when the power transistors are inactive during alternate positive and negative half-cycles of operation.

Abstract: A digitally compensated modulation system for frequency synthesizers has a single modulation input line with flat frequency response to zero hertz. The above is accomplished while eliminating circuit components and adjustments by integrating reference oscillator temperature compensation, modulation compensation for changes in the voltage controlled oscillator modulation sensitivity and modulation compensation for changes in the reference oscillator modulation sensitivity. Signals requiring modulation enter a microprocessor and are summed together with a microprocessor generated signal and a temperature compensation input to create a composite modulation signal. The composite modulation signal is then multiplied by appropriate constants and sent to the synthesizer.

Abstract: A receiver system for measuring the bearing of a target having ambiguity correction. The receiver system includes a four element antenna array, three receivers and two phase detectors. The system further includes switching means for selectively connecting the antenna elements to the receivers and the receivers to the phase detectors to obtain two pairs of bearing components, from which the target bearing is computed.