Abstract: A high pressure air reservoir, a pump unit and an air pressure sensor are provided on each wheel of a motor vehicle. The sensor senses the air pressure in a tire which is mounted on the respective wheel. The pump unit is controllable to selectively pump air from the tire into the reservoir to deflate the tire, or to cause air to flow from the reservoir into the tire to inflate the tire. A control unit which displays the sensed air pressure and controls the pump unit to inflate or deflate the tire is mounted inside the vehicle for operation by the driver, and is electrically connected to the sensor and pump unit by brush contacts provided between the wheel and axle or inductive coils provided between the wheel and an adjacent structural member of the vehicle.

Abstract: A method is provided for forming selective electrical contacts on a structure of alternating ultrathin semiconductor layers of two different types, so that electrical connection can be made separately to the layers of a given type. Selective etching of first one type of layers at one side of the structure and then the second type of layers at another side produces digitate edge patterns suitable for deposition of ohmic contacts. Any method can be used which directs particles of a conducting material onto the digitate edge portions at an angle to build up material on only one set of layers at a time. The gaps between adjacent protruding layers of the same doping type are filled in as the deposition continues. In this way the high-temperature steps required for diffusion or ion implantation activation are avoided. For a mesa-etched n-i-p-i chip the contact is allowed to extend onto adjacent regions of the supporting wafer so that further electrical contacting can be done in those regions.

Abstract: Ultraviolet (UV) light from a lamp or UV laser, such as a metal can short arc xenon lamp or excimer laser, respectively, is provided for cracking Group V and Group VI species comprising clusters (dimers and tetramers) or metal-organic molecules to form monomers (atoms). The UV radiation interacts with a molecular beam of Group V and Group VI species subsequent to their generation in a source cell and thermal cracking. The source cell may comprise an effusion source in molecular beam epitaxy (MBE) apparatus, a thermal cracker cell in gas-source MBE apparatus, or a gas injector cell in metal-organic MBE apparatus (MOMBE). Light from the UV lamp or laser is coupled into a vacuum chamber in which the source cell is located, at a point below the source cell and is then directed along a path parallel to the source cell by a first reflector and finally directed onto the thermally-cracked beam of molecules by a second reflector, where the UV radiation photo-cracks the molecular beam.

Abstract: A vehicle lighting system includes one or more central light sources, a plurality of optical loads including headlight lenses, an optical fiber network that extends from the light sources to illuminate the headlight lenses and other optical loads, and optical switches and oscillators that include respective input fibers illuminated from the light source and output fibers to respective optical loads, and operate by enabling and disabling optical connections between their input and output fibers. The headlight assemblies switch between high and low beams by moving their fibers vertically, and control beam diffusion by moving the fibers parallel to the lens axes, including an automatic diffusion adjustment for a headlight reflection from a vehicle in front.

Abstract: Laser beam speckle effects are mitigated by frequency chirping a single-mode laser beam, reflecting it off a speckling surface, and then integrating the reflected beam over at least one chirp period. The speckle reduction is comparable to the use of a multi-longitudinal mode beam having a bandwidth similar to the chirped frequency excursion, while leaving the beam compatible with nonlinear optical processes that are not compatible with multi-longitudinal mode beams. Where the nonlinear process is stimulated Brillouin scattering (SBS) phase conjugation, the beam can be chirped at a rate up to the order of ##EQU1## where .DELTA..nu..sub.B is the gain bandwidth and L is the effective SBS interaction length of the phase conjugator, and C is the speed of light. Other nonlinear processes with which the beam may be used include harmonic generation and Raman-based beam cleanup or wavelength conversion.

Abstract: Yields of FETs such as HEMTs are significantly improved by establishing an elongate gate contact opening in a patterning material with the patterning material over-hanging the opening along both its elongate sides and its ends. A contact metal is next evaporated both into the opening and onto the adjacent patterning material, with the overhang producing a continuous gap around the periphery of the gate contact between it and the metal on the adjacent patterning material. The adjacent metal is then lifted-off without disturbing the gate contact. The inward tapered profile in the elongate direction of the contact opening is achieved with multiple parallel e-beam scans, while a similar profile is achieved at the ends of the elongate scans by increasing the electron beam dose in the vicinity of the scan ends, preferably by scanning the beam at a substantial angle to the elongate direction near the ends of the opening.

Abstract: A leak detection system (50) including a flow accelerator for directing and accelerating leaking gas toward a sampling probe (70). A probe input tube (72) is inserted into one end (62B) of a larger diameter adapter tube (60) to position the end of the tube (72) past a suction opening (62D). The other end (62A) of the adapter tube is positioned to receive leaking gas. A suction is applied to the suction opening, which tends to draw the leaking gas into the adapter tube end (62A). Some of the leaking gas is drawn into the suction opening, and some into the end of the sampling tube. The suction causes the leaking gas to be accelerated toward the sampling probe input port. The suction can be created by a venturi (66C) through which is passed a gas under pressure. The acceleration of the gas through the venturi creates the suction. The flow accelerator significantly reduces the time required to locate small gas leaks.

Abstract: A fiber optic corporate power divider/combiner for use in fiber optic systems is provided. When functioning as an optical divider, the invention includes a dielectric lens for converting incoming optical energy from a divergent spherical wave to a plane wave. A micro-lens array in optical alignment with the dielectric lens functions to partition and focus the plane wave to provide a coherent phase optical dot pattern. A fiber bundle is provided to receive and uniformly distribute the coherent phase optical dot pattern. When functioning as an optical combiner, the invention includes the micro-lens array to convert an incoming coherent phase optical dot pattern from a plurality of divergent spherical waves to a plane wave. The dielectric lens optically aligned with the micro-lens array receives and converts the plane wave to a convergent spherical wave and a single optical fiber receives and transforms the convergent spherical wave into parallel rays for transmission.

Abstract: The three axes thruster modulation (8) of the present invention accepts three axes of input torque commands or angular acceleration commands and generates thruster selection and thruster timing (40) information which is used to fire thrusters (48) for the purpose of spacecraft attitude control and velocity change maneuvers. The modulation logic (8) works in all three axes simultaneously and is suitable for use with an arbitrary thruster configuration, including a configuration in which individual thrusters or thruster groups do not produce torques about mutually orthogonal axes. After thruster selection and on-times have been determined, the modulation logic (8) uses this information to compute a best estimate of the actual rate change (42) which is then compared to the commanded rate change (44) to develop a residual unfired rate change.

Abstract: A method of attitude control for spacecraft with flexible structures utilizes an estimator/state controller pair with on-board time-varying gain scheduling. The control method includes an attitude estimator (100) for each axis, which uses rate input from inertial reference sensors (4, 5, 6) to produce estimates (37, 38, 39) of each of the state variables. The estimator employs a predictor-corrector structure which computes initial rate and position estimates for each sample interval and corrects these values by weighing them with iteratively-calculated time-varying gains according to equations 35 and 36. The state controller (40) for each axis operates on these inputs, combining them with position and rate commands (41, 42) and weighing the results with time-varying gains calculated iteratively for each sample period according to equations 46, 47, and 48. The final result is a commanded control acceleration (50) which is forwarded to a thruster modulation logic.

Abstract: A low noise frequency synthesizer 10 that uses uses frequency dividers 13, 15, at least one of which(divider 15) is incrementable and decrementable in half integer steps, and analog gain compensation in a phase/frequency detector 14 to achieve lower noise, lower spurious levels and faster switching speed than traditional methods of frequency synthesis. The key features of the present invention are its half integer dividers 13, 15 and the ability to adjust the phase detector gain to compensate the loop for varying divide numbers. The synthesizer 10 comprises two dividers 13, 15 that provide two reference frequency signals that are a function of an input signal and an output signal of the synthesizer 10. A voltage controlled oscillator (VCO) 18 provides the output signal (f.sub.O) of the frequency synthesizer 10. A phase/frequency detector 14 compares the reference frequency signals and provides a phase error output signal that drives the VCO 18.

Abstract: A predistortion linearizer (20) is operative with a microwave signal, as may be provided by signal source (62) to linearize the gain of a power amplifier, such as a traveling-wave-tube power amplifier (74), by introduction of an amplitude and/or a phase distortion to the microwave signal wherein the distortion is inverse to a distortion introduced by the power amplifier, thereby to compensate for the distortion of the power amplifier. The linearizer is constructed of two channels (22, 24) which are operated in parallel but approximately 180 degrees out of phase, with an additional phase increment provided by delay lines (46, 56) to offset one channel from the other channel by a phase difference in a range of approximately 160-200 degrees.

Abstract: A receiver for use in digital cellular communication systems determines the type of data transmitted without having to decode the data. Digital cellular communication systems typically use convolutional forward error correction (FEC) coding to allow for error detection and correction at the receiver. The type of encoding is different depending on whether voice data or control data is transmitted. In general, FEC coding is a redundant coding of the encoded data so that for a given encoding algorithm with FEC coding, there will be a limited number of valid code sequences less than the total possible number of code sequences for a transmission of the same number of bits. This characteristic is used to identify the type of encoding without decoding the received information. Consequently, decoding requirements are reduced to those corresponding to the active transmitting encoder, resulting in receiver complexity reduction.

Abstract: A spectral line selector for a laser comprises a diffraction grating that images a waveguide exit plane back into the waveguide with an essentially exact reproduction of the waveguide output intensity and phase distribution and with a predetermined wavelength. The selector also comprises lenses disposed between the waveguide exit at a point between the exit opening and the grating, the lenses providing a magnification and a phase compensation to the beam passing therethrough such that the phase of the beam returned to the waveguide matches that of the exiting beam. Thus, coupling losses due to clipping of the returned beam at the entrance to the waveguide bore and coupling losses due to a mismatch of the returning field phase to that of the waveguide mode are made essentially zero.

Abstract: A data router for receiving input data, having a timing characteristic, and transmitting output data that is either bursted or non-bursted. The non-bursted data comprises frames of data with each frame comprising slots of data, each slot having a position and a number. The invention (200) provides translation between bursted and non-bursted formats and includes an input buffer circuit (104) for receiving input data from an input channel and storing the input data as the input data is received from the input channel. An output buffer circuit (210) is included for formatting the stored input data, translating between bursted and non-bursted data formats and outputting the formatted and translated data to an output channel. A sequencer (105) routing controller circuit controls the operation of the input buffer circuit (104) and output buffer circuit (210).

Abstract: A mobile station cellular telephone transmitting system having a digital data source, waveform map, FIR filter with eight taps, a zero force circuit, start/end burst detection circuit, quadrature modulator, upconverter, and power amplifier. The ramping of the power output at the beginning and end of each frame slot or burst is controlled by forcing the first and last symbol of the burst's FIR filter output to zero.

Abstract: A satellite wide area communications network (10) includes a remote transmitter/receiver (28A) that is coupled through a modem unit (30A) to multiple card readers (12A-1 to 12A-n). A master transmitter/receiver (26) is satellite linked to the remote transmitter/receiver and is coupled through a central packet network (16) to multiple host computers (18-1 to 18-j). A network host computer address is determined for each transaction card inserted in the card readers, and the network address is processed to establish a direct link to the host computer for the card through the modem unit, the satellite link (22A, 20, 24), and the central packet network.

Abstract: An autotuning combiner particularly for use in combining signals for radio telephony transmission. The combiner has a series of filter cavities each with an adjuster for fine-tuning the cavity to an input carrier signal. The combiner cavities are stabilized from positional drift in the absence of a carrier signal by means of a mechanical brake which holds the adjuster or a pilot signal generator which simulates the absent carrier signal.

Abstract: A system and method for frequency acquisition by a mobile receiver 14 in a cellular communication system. Data for part of a frame 10 is sampled. Synchronization pattern 36 is rotated by a pattern rotator 37 to simulate fixed frequency offsets. The known sync pattern 36 is correlated with the sampled data by correlator 30 for a number of phase advances corresponding to the simulated fixed frequency offsets. The peak outputs 54 and 58 of the correlator 30 for the number of fixed frequency offsets is interpolated by parabolic interpolator 46 to adjust the receivers voltage controlled crystal oscillator 49 to reduce the offset.

Abstract: A frequency-based neural network in which the state of a neuron is indicated by the frequency of an impulse stream emitted by the neuron uses an interconnectivity structure employing a frequency-modulation multiplexing scheme to weight and communicate the pulse stream from an emitting neuron to receiving neurons in another network level.