Abstract: A double sideband suppressed carrier modulator apparatus for combining two serrodyne (i.e., single sideband) modulators to achieve double sideband, suppressed carrier modulation. An RF input signal is divided into two carrier signals which are 90 degrees out of phase and applied to the serrodyne modulator units. The modulated signals from the modulators are combined in a 90 degree power divider to provide a double sideband suppressed carrier modulated output signal.

Abstract: A digital phase meter to measure the phase difference between an input signal and a reference signal and output this phase information in the form of an eight bit number. The input signal and the reference signal, which are sinusoidal, are conditioned to a more defined leading edge by a high speed differential voltage comparator and a dual/differential line receiver. A series of uniquely configured D flip-flops are used to detect the leading edge of both the signal input and the reference input. An AND gate then acts as a switch that is activated on the leading edge of the signal input. The time interval between the two positive leading edges of the input signal and reference signal specifies the phase difference. The AND gate is in the high state for this duration. The phase difference is converted into an 8-bit binary number via two 4-bit cascaded counters. The high output of the AND gate is used to enable the counters for the duration of the phase difference.

Abstract: A CCD gate definition process utilizing a thin film layer in a double masking process to form a first and second oxide layer over the polysilicon gate material to provide a profiled and tapered oxide layer over the gate without any re-entrant oxide steps.

Abstract: A pulse repetition modulator apparatus having a pulse width modulator to supply a series of maximum transmitter power output bursts that have been generated with a pulse time correlation to the sampled amplitude of the voice signal input to the link. The output bursts would therefore be of variable length with the durations proportional to the amplitude of the voice input signal.

Abstract: An apparatus for locating passive interference sources by using a pair of different RF signals in conjunction with an acoustic signal to generate intermodulation products in metal-to-metal junctions. The acoustic tagging technique utilizes a focused, high power beam of acoustic energy to mechanically vibrate the suspected offending junction. This mechanical vibration causes the level of intermodulation products that are generated in the junction to become amplitude modulated at the frequency of the acoustic illumination. The detection of the AM sidebands with a low noise RF receiver that is tuned to a particular intermodulated component, permits the offending junction to be located.

Abstract: A laser weapon fire control computer apparatus for responding in real time to the escort/threat scenario that confronts the weapon. The first control computer apparatus compares the threat data with stored predicted scenarios to develop a firing strategy menu which takes into account the fact that the laser energy is instantaneously propagated to the target but requires a substantial amount of time to inflict damage. The fire control computer apparatus utilizes the weapon's status, dwell time, slew time and fuel limits to yield a weapon pointing sequence and weapon on-off times.

Abstract: A wide-band amplifier apparatus utilizing a low frequency and a high frequency phase lock loop to achieve low phase delay at the loop bandwidth. The bandwidth products of the low and high frequency loop paths are combined and applied to the voltage controlled oscillator to minimize phase delay and to achieve a more stable loop.

Abstract: A low pass T-section digital phase shifter apparatus having a pair of serially connected inductor-diode combinations connected in series which includes a parallel circuit connected between the common junction and ground. The parallel circuit has an inductor in parallel with a series capacitor and diode to provide a balanced insertion loss at each diode switching state. When the diodes are in the forward-biased state they act as closed short circuit switches. When the diodes are reversed-biased, the inductance in the series circuit resonates with the diode capacitance to provide a short path to the RF signal to pass the center frequency of the RF signal at the desired phase.

Abstract: A ferromagnetic eddy current probe apparatus having a double shielded magnetic coil to reduce the size of the magnetic filed and to generate a sharply focused electromagnetic field. A ferromagnetic steel alloy provides a double shield effect for greater concentration of the electromagnetic field onto a test specimen, and also to prevent probe tip wear and deformation when used to inspect fastener holes with a high speed designed feature maintenance the size setting of the probe (coil-end) diameter. An expansion slot in the end of the probe provides a spring action during probe radiation to keep a constant contact with the wall of a fastener hole. The ferromagnetic probe portion is removeable from the shank-end (a non-metallic portion of the probe) for easy repair or replacement and provides electrical isolation to prevent shorting of the signal.

Abstract: A magnetostatic wave frequency analyzer apparatus utilizing forward volume waves. A single input transducer is arranged opposite a plurality of output transducers to receive the different frequencies of the generated magnetostatic forward volume wave. A geometric ground plane is positioned in the propagation path between the input transducer and the plurality of output transducers to demonstrate the propagation characteristics of magnetostatic forward volume waves (MSFVW) in the 2-6 GHz range. The waves were propagated in two inch diameter YIG La-doped films of varying thickness (20,30,40 microns). The waves were launched by the microstrip input transducers on an alumina substrate. Receiver transducers were also on the substrate, but placed approximately one inch away, in a semi-circle with 10 degrees of arc between adjacent transducers.

Abstract: A low pass .pi. section digital phase shifter apparatus having an inductor and a diode connected in series between two identical parallel circuits. The parallel circuits connect to the series inductor/diode circuit at both the input and output and each circuit has inductor connected in parallel with a capacitor and a diode to provide balanced insertion loss at each diode switching state. When the diodes of the circuit are in the forward biased state they act as closed short circuit switches. When the diodes are reversed biased, the inductance in the series circuit resonates with the diode capacitance to provide a short circuit path to the RF signal to pass the center frequency of the RF signal at the desired phase.

Abstract: A tally cell circuit for counting the number of logical ones in an input signal utilizing a parallel-series combination of four CMOS field-effect transistors. The number of input ones in the input are expressed in a binary code at the output of the tally cell circuit.

Abstract: A rotor blade test apparatus having a striking solenoid to strike a rotor blade to generate an audio signal. A microphone receives the audio signal and applies it to a spectrum analyzer wherein the predominant natural frequencies of the rotor blade are determined.

Abstract: An extra high frequency .pi.-section digital phase shifter apparatus having a diode connected between two identical parallel shunt circuits. The parallel shunt circuits connect to the series inductor/diode circuit at both the input and output and each parallel shunt circuit has inductor connected in parallel with a capacitor and a diode to provide balanced insertion loss at each diode switching state. When the diodes of the circuit are in the forward-biased state they act as closed short circuit switches. When the diodes are reverse-biased, the inductance in the shunt circuit resonates with the diode capacitance to provide a short circuit path to the RF signal at the center frequency of the RF signal at the desired phase.

Abstract: An extra high frequency T-section digital phase shifter apparatus having a pair of back to back diodes connected between the input and output terminals with a parallel circuit connected between the common junction and ground. The shunt parallel circuit has an inductor in parallel with the series combination of a capacitor and a diode to provide a balanced insertion loss at each diode switching state. When the diodes are in the forward-biased state they act as closed short circuit switches and in the shunt circuit, the inductance resonates with the diode capacitance to provide a perfect transmission for the RF signal.

Abstract: An X-cut, 33.44 degree quartz crystal for propagating surface acoustic waves with a temperature stability in the order of -0.0209 ppm/C.sup.2. The crystal orientation requires only a single rotation (33.44.degree.) from the crystal axes. This orientation is substantially simpler than previously reported cuts with comparable temperature stability which typically require three rotations. The X cut orientation has a surface acoustic wave (SAW) velocity of 3175 m/sec, an electromechanical coupling (.DELTA.v/v) of 4.times.10.sup.-4, and a power flow angle of 2.7 degrees.

Abstract: The signal-to-noise enhancer can be used in frequency memory loops to prevent loop capture by noise. If a frequency selective limiter is incorporated in the loop, more than one signal can be stored simultaneously because the limiter prevents the loop amplifier from saturating. At present, the limiter must be a separate device. The frequency selective signal-to-noise enhancer/limiter apparatus comprises an enhancer apparatus and a limiter apparatus on a single substrate, using a single pair of magnets to bias both units.

Abstract: A multi-microprocessor apparatus utilizing a plurality of central processing units arranged in a parallel configuration. Each central processing unit which has its own local memory unit, communicates with a common memory unit on a time shared basis that is synchronized between each central processing unit and the common memory unit.

Abstract: A hand off integrator apparatus utilizing first and second recirculating integrator units in series to integrate a series of input pulses in order to detect the presence of weak signals in a high background noise environment.

Abstract: A pulsed modulator apparatus having a ground deck clock driver unit to provide pulse stretching and on-off trigger signals for a floating deck transistor switch unit. Voltage isolation is achieved between the ground and floating deck units through the use of trigger transformers.