Abstract: A differential phase shifting structure is disclosed, employing corrugated ridges in square or round waveguides or in coaxial lines operating in the TE.sub.11 mode. The structure provides a substantially constant differential phase shift between two waves polarized orthoganally to each other. The corrugations in the ridge provide a series inductance which can be optimized with the shunt capacitance of the ridge to provide a characteristic impedance matching that of the unloaded structure. The corrugated ridges provide increased differential phase shift per unit length. The differential phase shifting structure is particularly well suited to such applications as circular polarizers, quarter wave plates or polarization rotating half-wave plates.

Abstract: A method and apparatus for processing digital data representative of a digital array of points of a source image including a source image memory (12) or digitized camera (40) for providing a source image as a digital array of points, with provision for generating an end of array, or end of frame signal, (32) each time that the array has been computationally adjusted and transferred to a destination image memory. A control processor (14) includes a convolution kernel algorithm having the elements thereof configured for establishing a computational sequence or offset (18, 10) for each point in the array relative to a reference point, with each element having a constant value for computational adjustment of the array for each frame time represented by that element.

Abstract: A movable open center mounting for the tool of an ultrasonic wire bonding machine employs ball-bearing rollers (22, 24, 30, 32) to permit limited motion of the wire bonding tip (13a) substantially constrained to a vertical line with a minimum of tip skid. The mounting structure which is all positioned on one side of the tool tip includes a frame (10) of inverted U-shape having a pair of mutually spaced ball-bearing rollers (22, 24, 30, 32) on the end of each frame leg and a transducer support (12) positioned between the frame legs and having fixed roller contacting rods (90, 92, 96, 98) extending fore-and-aft between and partly under each of the respective rollers.

Abstract: A quick-release interfacing assembly (165) comprising first and second carriers (53, 53a), a plurality of module assemblies (11) carried by the first and second carriers (53, 53a) and a coupling (73, 75) for joining the first and second carriers (53, 53a) together to form a double cartridge assembly (71). A panel receiver (91) receives the double cartridge assembly (71) and couples the double cartridge assembly (71) to a test device. Each of the module assemblies (11) includes a connector body (13), a pressure member (27), and a flexible sheet (17) carrying contacts (21, 23) thereon.

Abstract: A hybrid power combiner and controller device is disclosed. The device includes a multiple branch hybrid network, with PIN diodes employed to selectively short circuit the midpoints of the branch lines to ground. With the PIN diodes biased to the open circuit condition, the device behaves as a conventional hybrid combiner, for example, to combine the power produced by two input sources at the device output port. With the PIN diodes biased to the conductive condition, thereby shorting the branch line midpoints to ground, the device behaves as a matched multiple stub filter tuned to the desired band. Substantially all the power provided by one input power source will be provided at the device output in this case.

Abstract: An electromagnetic energy interference seal arrangement is provided for use in light beam touch panel systems. The electromagnetic energy interference seal includes the use of waveguides associated with the light beam sources and detectors to improve light beam touch panel performance. The waveguide size is selected so that it operates as a waveguide above cutoff frequency for the light beams but operates as a waveguide below cutoff frequency for blocking electromagnetic energy interference. The waveguides improve the light beam signal to noise ratio since they shade the detectors from reflections and from extraneous light such as from overhead room lighting. Bonding of part of the electromagnetic energy interference seal is effected by an electrically conductive compound which enables nondestructive disassembly when required. Environmental sealing strips are provided to cover the waveguide apertures to protect against dust, liquids and other environmental contaminants.

Abstract: A system for optimizing the RF input drive to a TWT amplifier over a frequency band of interest is disclosed. The system includes a microprocessor-based controller, an RF detector for detecting the TWT output, and a variable attenuator for adjusting the input drive to the TWT. The controller comprises an analog-to-digital converter for converting the video detector signals and providing digital RF level signals which are representative of the TWT output power level. Frequency data is also provided to the controller indicating the frequency of the RF exciter signals driving the TWT. The controller is, therefore, provided with frequency and RF level information, and is adapted to control the attenuator to adjust the TWT input drive for optimum TWT output. The system is operable in a calibration mode wherein the controller follows a calibration algorithm to determine the optimum attenuator setting, resulting in the maximum RF output, for each frequency of interest.

Abstract: A dual band, phased array antenna especially adaptable for tactical radar capable of performing search, track and identification in a hostile jamming environment. The dual band array antenna is essentially two antennas sharing a common antenna aperture. The two antennas possess separate feed system and beam steering control. Thus, the beams for each frequency band can be steered independently and simultaneously. This design utilizes an ultra-wide band radiating element which can operate over approximately an octave bandwidth encompassing two adjacent microwave bands. In particular, the dual band signals can be received efficiently by the radiating element. A dual band coaxial-to-waveguide transition can be used to carry the signals to a diplexer. The dual band signals are separated at the diplexer and can be processed in separate feed networks.

Abstract: A multiple range interval clutter cancellation circuit for MTI radars is disclosed, for assuring cancellation of narrow band clutter in the second or further range interval, while preserving wideband cancellation in the nearer range intervals and economizing on the number of fill pulses. The circuit includes two clutter cancellers. One canceller has a relatively narrow band clutter rejection bandwidth, and effectively a higher number of fill pulses in relation to the clutter rejection bandwidth and effective number of fill pulses for the second canceller. The outputs of the two cancellers are subjected to an AND gate function, such that only targets which pass through the clutter rejection bandwidth of both cancellers are reported as a target. The circuit obtains the elimination of returns from ambiguous range interval clutter with less transmitted energy and time than conventional canceller circuits.

Abstract: A digital cathode current control circuit for controlling the cathode current of a traveling wave tube (TWT) amplifier is disclosed. The cathode current control circuit includes circuitry for providing a comparison signal indicative of the occurrence and amplitude of TWT cathode current pulses; clocking circuitry responsive to the comparison signal for providing a clock signal delayed relative the occurrence of a cathode current pulse; comparison circuitry for comparing the comparison signal with predetermined reference signals indicative of a predetermined cathode current level, and for providing adjustment signals indicative of the adjustment of the TWT cathode current necessary to tend to achieve the predetermined cathode current; and counter circuitry clocked by the delayed clock signal for providing an output count in response to the adjustment signals.

Abstract: A charge packet differencer is implemented in a charge coupled device in such a manner that a first charge packet may be subtracted from a second charge packet thus giving a resultant charge packet equal to the difference between the first and second charge packets. The charge coupled device differencer comprises a semiconductor substrate in which there is formed first and second charge transfer devices, first and second charge substraction mechanisms, and a charge reservoir cooperating to produce a charge packet output representative of the difference between two input charge packets using a gate charge subtraction technique.

Abstract: A local area network transceiver (10) which includes a transmitter section (20) for providing a data signal and a pilot tone signal which are combined as a transmit signal for transmission on a local area network data bus (11). The transceiver further includes a receiver section (30) which receives signals on the data bus (11) and includes circuitry for filtering the received signal into a received data signal and a received pilot tone signal (23,25,27). Comparison circuitry (29,31,33) is responsive to the transmit pilot tone signal and the received pilot tone signal, and produces an output indicative of whether the received pilot originated from the transmit pilot tone. Logic circuitry (35,37,39,41,43) is responsive to the comparison output to provide outputs indicative of whether transmission collision has occurred or whether activity is present on the data bus.

Abstract: A high resolution pipelined digital-to-analog converter is disclosed having at least one switching circuit for conveying charge to at least one conversion capacitor upon receipt of a digital signal during the first half of a clock cycle. Additional switching circuits are provided for transferring the charge from the conversion capacitors to a feedback capacitor during the second half of the clock cycle. Also provided is a circuit for discharging an analog output from, and preventing the charging of, the feedback capacitor during the first half of a succeeding clock cycle. In a preferred embodiment, the pipelined digital-to-analog converter comprises a first plurality of electrical circuits having at least one feedback capacitor and a plurality of conversion capacitors adapted for accepting digital and analog inputs, wherein the ratio of the feedback capacitance to each of the conversion capacitances is substantially independent of the resolution of the converter.

Abstract: A single channel antenna tracking system for frequency-hopping communication systems. The tracking system utilizes the synchronization pulses accompanying the frequency-hopping data bursts. The receive antenna system includes an antenna feed network for providing sum and difference antenna receive signals. The tracking system comprises a tracking switch circuit which normally switches the antenna system sum signal to the receiver during reception of a frequency-hopping data burst. During the reception of an agile synchronization pulse, however, the switching system is adapted to timeshare between the antenna sum signal and the difference signal or signals. During the synchronization pulse duration, the receiver thus receives a single waveform which during one portion of the sync pulse represents the sum signal and during one or two other portions represents the difference signals. The respective sum and difference signals may then be processed to determine the antenna tracking error.

Abstract: An electrical interconnection assembly is disclosed for use with high voltage devices such as traveling-wave tubes. The assembly includes an electrically insulating housing having a plurality of recesses formed in its outer and inner surfaces. Leads from the high voltage device can be connected directly to respective conductive pins mounted in recesses in the housing inner surface, and electrical conductors from a power supply can be connected directly to respective conductive pins mounted in recesses in the outer surface of the housing and which are electrically connected to respective conductive pins on the inner surface. Protruding staggered gripping elements on the housing outer surface and on a removable cover plate for the housing minimize the possibility of separation of electrical conductors from the conductive pins.

Abstract: A phase-locked frequency synthesizer (10) having a voltage controlled oscillator (40), a divider circuit (60), and a sample-and-hold phase detector (30, 80, 90, 100, 110) which utilizes gain compensation (90,110) for optimizing phase-locking speed. The sample-and-hold circuit (FIG. 6) also includes circuitry for substantially reducing perturbations at its output. The frequency synthesizer further includes control circuitry (70) and a reference frequency generator (20) for quickly reinitializing the synthesizer in response to a command to change frequency.

Abstract: A process is disclosed for preparing selectively doped and recrystallized silicon-on-insulator semiconductor wafers, and wafers prepared thereby, wherein successive amorphizing and annealing sequences are utilized to optimize the defect structure and doping of multiple regions or islands of the silicon on an insulator substrate. Prior to fabrication of the active devices, the various silicon islands are given customized ion implantation treatments to amorphize a silicon near-interface layer under differing sets of implantation conditions. The entire wafer is then annealed to achieve downward epitaxial recrystallization of the amorphized near-interface layers in all of the amorphized islands, growing on the near-surface crystalline layer of the silicon remote from the interface. The near-surface layers of the islands are then amorphized and annealed to achieve upward epitaxial recrystallization of the layers on the underlying silicon layer.

Abstract: A technique for a vibration isolation module (VIM) used for towed arrays is disclosed. The VIM has a stretchable cable on which is mounted one or more rigid spacers which make contact with an outer hose formed of a flexible material having a selected vibration attenuation characteristic. The spacer transmits energy between the parts of the VIM which contact the spacer for attenuation purposes. The spacer is "soft mounted" on the stretchable cable so that it may be moved by a limited amount along the cable in response to forces of a specified minimum magnitude. This ability to move allows adjustment of the internal parts of the VIM during use to avoid concentrating stress at any one particular contacting area. Disclosed is an embodiment where two sleeves are used to abut the spacer at opposing ends thereof.

Abstract: A compact, full color, light projection system using a liquid crystal light valve (LCLV) and a unique combination of optical devices. The LCLV operates to modulate a light beam which has been polarized by one of the optical devices. The modulated light beam is converged and registered by other optical devices to form the output image.

Abstract: Edge conduction in a silicon-on-sapphire transistor is minimized by a process which permits precise doping of the edge channel regions of the transistor. The silicon island (19) containing the transistor (24) is precisely doped around its edges by ion implanting an epitaxial silicon layer (13) on a sapphire substrate (11), with an oxide mask (29) covering, with the exception of a narrow peripheral edge (37), the portion of the silicon which is eventually to form the island (19') on which the transistor is to be constructed. The mask (29) is then expanded by the addition of a sleeve (43) to cover the additional peripheral edge region (37) in the silicon. When the silicon is subsequently etched using the expanded oxide pattern 45 as a mask, the periphery of the remaining silicon will be doped to a predetermined depth (37) corresponding to the width of the sleeve (43).