Abstract: A display is disclosed for indicating in the peripheral vision of a viewer the deviation between the actual position of a target and a reference position such as an aiming point. Light sources are arranged around a common circle which is of a particular size such that when viewed from a particular distance, the viewer sees the display by peripheral vision. There are two sets of light sources, one of which indicates the azimuth and elevation deviations of the target from the aiming point and the other of which may be used to indicate range. The direction of azimuth and elevation deviation is indicated by flashing selected light sources around the circle and the magnitude of deviation is indicated by flashing those light sources at a flash rate indicative of the magnitude. Range is indicated by causing the second set of light sources around the circle to illuminate upon attainment by the target of a certain range.

Abstract: A mask and solder form for mounting of multi-leaded integrated circuit carriers to printed wiring boards during a soldering process is disclosed. The form comprises a multi-layer composite frame-like structure. The top layer is a translucent sheet, and is provided with a solder and flux strip. The top layer is bonded to a divider layer which is slotted to accept the multi-wire leads of the circuit carrier. The bottom surface of the divider layer is coated with adhesive. The transparent top layer permits precise alignment of the leads of the carrier and the printed wiring board lines. The divider layer blocks the flow of molten solder between leads by providing each wire with its own individual slot. The form is well suited to production loading of the circuit carriers on the printed wiring boards for vapor phase soldering.

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 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 liquid crystal light valve projector is disclosed which includes a first color separator responsive to unmodulated polarized light for reflecting light of a first primary color, for transmitting the remaining portion of the incident unmodulated polarized light, and for internally reflecting incident light; a transparent plate window for transmitting incident unmodulated polarized light to the first color separator and for internally reflecting the light of the first primary color reflected by the first color separator; a second color separator responsive to the light transmitted by the first color separator for reflecting light of a second primary color and for transmitting the remaining portion of the incident light which includes a third primary color, whereby the second color separator reflects the light of the second primary color to the first color separator which internally reflects such second primary color light; and light modulators respectively responsive to the light of the first, second, and thi

Abstract: A system for automatic alignment of two pulses is disclosed. The disclosed system is particularly adapted to align the cathode current pulse supplied to a TWT amplifier with the RF exciter pulse so as to improve the efficiency of the TWT amplifier. The system includes a programmable delay circuit for selectively delaying the cathode current pulse after the system trigger. A pulse alignment signal indicates when the two pulses are in alignment. A system controller carries out a calibration algorithm to interatively change the delay while monitoring the alignment signal to determine the calibrated delay setting resulting in pulse alignment. The calibrated delay setting is then stored in memory, and is employed by the controller during the normal operation mode to adjust the programmable delay circuit to the calibrated value.

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: 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 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 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 includes sample-and-hold circuitry (FIG. 6) having variable efficiency. Specifically, the sample-and-hold circuitry provides a sampling pulse of variable width which is controlled to be wider during acquisition and narrower during steady-state operation.

Abstract: A limiter amplifier having a pair of transistors connected in a common emitter, balanced push-pull amplifier type of circuit arrangement is disclosed. The transistors are interconnected by a series tuning capacitor at their emitters. A separate constant current source is connected to each of the emitters of the transistor pair. By selecting the value of the tuning capacitor to resonate with the inherent inductive component of the emitter source impedances in a particular frequency band, the limiter amplifier acts as a differential amplifier in the particular frequency band. The ac coupling of the emitters gives the limiter amplifier a bandpass filter type feature as well as high gain and low phase variation over large dynamic ranges of input signal amplitude. Impedance matching/buffer circuitry and isolation circuitry are also disclosed which permit the cascading of limiter amplifier gain stages.

Abstract: A particular plastic material is formed into the desired component shape and then is plated by a process comprising; a particular surface preparation step, electroless deposition and electrolytic deposition which results in excellent plating adhesion. The plated component is then assembled with other components manufactured in the same manner or with compatible metal components such as aluminum and soldered together in a disclosed hot oil dip soldering process. In the soldering process, the plated plastic substrate is completely immersed in a hot oil medium at a temperature of approximately 243.degree. C. (470.degree. F.) for a time of approximately 60 seconds for solder reflow.

Abstract: A solid state microwave power combiner is disclosed having a central combining cavity with a plurality of coaxial oscillator circuits disposed about and coupled to the cavity. The oscillator circuits are oriented such that their longitudinal axes are parallel with the central axis of the combining cavity. They alternate in configuration about the cavity such that adjacent oscillator circuits have their power generating diodes located on opposite sides of the cavity. In one embodiment, the coaxial lines used in the oscillator circuits have two parts of different sizes. The oscillator circuits are oriented about the cavity so that the smaller sized coaxial line part of one is adjacent the larger sized coaxial line part of the next. Both rectangular and circular combining cavities are disclosed.

Abstract: An analog phase interpolator for use in Fractional-N frequency synthesis is disclosed. The interpolator employs a precision gating circuit adapted to generate analog signals indicative of a precisely determined time interval. The signals switch a precision correction current to precisely compensate for the phase detector "beat note" to reduce the magnitude of FM spurious signals. The time interval is inversely proportional to the synthesizer output frequency and the gating circuit automatically compensates for changes in the output frequency. The precision gating circuit includes a prescaler circuit for prescaling the output signal frequency to provide a clock signal, and is responsive to an "initiate" pulse to provide two pulses delayed by a predetermined number of clock signal periods. A very high degree of time integrity exists in the relation of the edges of the two pulses.

Abstract: A self-calibration technique which provides detector responsivity normalization for a charge-coupled device, hereinafter referred to as CCD, area imager. The CCD area imager is designed such that the detectors can be electrically decoupled from CCD multiplex register inputs. Calibration reference and gain normalization are provided by a pulsed light source and an analog divider circuit. This technique is applicable to both CCD visible imagers which are fabricated on an intrinsic semiconductor substrate and CCD infrared imagers which can be fabricated on an extrinsic or intrinsic substrate. The technique is applied to a visible imager for illustration of its self-calibration capability.