Abstract: A tunable narrow-band filter is described incorporating a phase-locked loop that includes a phase detector, amplifier, loop filter, and voltage controlled oscillator wherein the loop filter transfer function is derived or extracted from the desired closed-loop transfer function that is of order n=3 or greater. The loop filter may furthermore have finite transmission zeros or peak attenuation at specific frequencies close to the passband which also appear in the characteristics of the narrow-band filter.The invention overcomes the problem of providing peak attenuation close to the passband of an electronically tunable narrow-band filter.

Abstract: An integrated circuit including a charge-coupled device for accumulating charge in a potential well and pair of metal-oxide semiconductor (MOS) transistors connected to form a differential amplifier. The gate of one transistor is coupled to the CCD potential well. The integrated circuit is provided with means for coupling the differential outputs, the drain of each transistor of the differential amplifier, to the differential inputs of an external op amp. Means are provided for coupling electrical feedback from the output of the op amp to the gate of the second transistor of the differential amplifier.

Abstract: A radiant energy sensor incorporating a substrate having two electrodes on a first surface and a third electrode on a second surface is described wherein a first electrode collects a first portion of charge generated by radiant energy absorbed in the substrate to provide an output signal and wherein the second electrode is biased with a voltage supply to attract and remove a second portion of charge from the substrate and first electrode to prevent blooming due to excess charge. The sensor includes a layer of semiconductor material deposited over the substrate and over the first and second electrode to conserve detector area and to permit the location of circuitry over top of the second electrode.

Abstract: A method for eliminating the latch-up effect in integrated circuits having parasitic pnpn structures has been described comprising the step of irradiating the circuit with high energy particulate ions to provide low lifetime regions in the circuit to lower parasitic transistor gain.The invention overcomes the problem of latch-up effect in integrated circuits where parasitic pnpn structures act as thyristors or silicon-controlled rectifiers which provide a low impedance path across the pnpn structure when the thyristor or silicon-controlled rectifier is turned on such as by transient ionizing radiation or by transient circuit voltages which forward bias the external junctions of the pnpn structure.

Abstract: Electroacoustic apparatus is described incorporating a substrate having a transducer on an upper surface and a transducer on a lower surface positioned for receiving bulk acoustic waves; substrate taper along with transducer geometry are combined to provide bulk acoustic signals in the near zone or Fresnel zone which provide for phase and amplitude cancellation of a triple transit signal.The invention overcomes the problem of spurious triple transit signals in bulk mode acoustic delay lines for input signals having a wide bandwidth, such as an octave, and where the delay times are short such that the bulk acoustic wave remains in the near zone or the transition region between the near zone and far zone.

Abstract: A circuit for use with sensors for providing background subtraction of signals below a predetermined frequency is described incorporating a first transistor for providing a zero to low frequency path and a second transistor or charge coupled device for providing a desired signal path wherein the g.sub.m of the first transistor is large compared to the g.sub.m of the second transistor or CCD device and the first transistor transconductance decreases at frequencies above the time constant determined by the gate capacitance of the first transistor and a resistor in series with the gate.The invention overcomes the problem of large signals in relation to a desired signal during sensing of radiant energy such as infrared. In particular, large background signals tend to saturate signal storage shift registers during time delay integration or just time integration.

Abstract: Apparatus for providing a plurality of filtered outputs is described incorporating a substrate suitable for propagating surface acoustic waves having an input transducer, a first plurality of spaced-apart taps coupled together, a second plurality of spaced-apart taps coupled together where at least two of the second plurality of taps are positioned in spaces between the first plurality of taps.The invention overcomes the problem of providing separate substrate surface area for each plurality of taps coupled together.

Abstract: A microwave combiner assembly is described incorporating a coaxial transmission line having a plurality of diodes exhibiting negative resistance at high frequency mounted between the center conductor and the outer conductor of the transmission line. Each diode is mounted on a segment forming a portion of the center conductor which are separated by slots containing lossy dielectric. A signal is capacitively coupled from each diode by capacitively coupling each segment to a common center conductor. Each diode is biased by coupling a bias voltage to each segment. The microwave combiner overcomes the problem of mechanically assembling a plurality of diodes in an oscillator or amplifier while attenuating anti-phase currents in the diodes indicative of undesired oscillator modes.

Abstract: Apparatus for generating noise is described incorporating means for generating a noise frequency spectrum, a plurality of voltage controlled oscillators and means for coupling the voltage controlled oscillators to an output.The invention overcomes the problem of a single voltage controlled oscillator which could not slue and settle at an appropriate frequency prior to being coupled to an output which resulted in undesired frequencies being generated during this slueing and settling time.

Abstract: An iris for a stage of a receiver protector is described incorporating a metal plate having a slot opening wherein the electric field across the slot opening is enhanced by tapering or beveling the edges of the slot.The invention overcomes the problem of high firing threshold and high recovery time of a gas plasma by providing metal in close proximity to the gap for providing free electrons.

Abstract: A receiver protector is described incorporating a waveguide containing several isolation stages followed by at least one iris plate filter.The invention overcomes the problem of RF or microwave leakage power of out-of-band frequencies some of which may be generated by non-linear elements in the prior isolation stages of the receiver protector.

Abstract: A method and apparatus for removing heavy metal impurities such as gold, silver, nickel and copper from a crystalline substrate is described incorporating a damaged crystalline layer which may be formed by excessive doping to trap or getter heavy metal impurities to enhance the majority carrier lifetime of the detector material.The invention overcomes the problem of degraded responsivity in radiant energy crystalline detectors after high temperature processing, in excess of 900.degree. C., which permits surface contaminants such as gold, silver, nickel and copper to diffuse through the detector material raising the net donor density.

Abstract: Electroacoustic apparatus is described incorporating a substrate having a plurality of transducers on an upper surface and a plurality of transducers on a lower surface each positioned for receiving bulk acoustic waves from a respective transducer on the upper surface wherein each receiving transducer has a predetermined acoustical path length from its respective transducer on the upper surface, means for coupling an input signal to the transducers on the upper surface, and means for coupling an output signal from the transducers on the lower surface. The invention further provides a plurality of bulk mode acoustic delay lines having predetermined acoustical path lengths which are coupled in parallel to suppress the triple transit signal.The invention overcomes the problem of spurious triple transit signals in bulk mode acoustic delay lines for input signals having a wide bandwith, such as an octave.

Abstract: A power amplifier that divides input power among a plurality of parallel channels through a radial line divider, amplifies the power in each channel with three terminal devices, and combines the amplified power in a radial line combiner to produce an output signal. The radial line divider/combiner includes a radial transmission line having a plurality of sectors symmetrically disposed around the inner radius of a supporting annular substrate. The sectors are connected to respective three terminal devices through microstrip transmission lines, and are isolated from laterally adjacent sectors by thin film isolation resistors.

Abstract: A suppressed carrier radio signaling system is described in which there is a servo loop utilizing balanced circuit techniques and using the carrier as the reference, in which a phase detector (or coherent demodulator) constantly senses the phase difference between the carrier source and the carrier component in the output signal to derive an error signal which is used to vary the amount of the carrier component toward zero.

Abstract: An angle modulation radio communications system having privacy and security characteristics. The system utilizes two or more communication units, one at the transmitting terminal and the other at the receiving terminal of identical functional construction and each having a transceiver module, an antenna and a phase reversal modulator-demodulator module between the transceiver module and the antenna. Complex phase reversal modulation of the transmitted carrier is accomplished which produces a constant amplitude spread spectrum frequency-modulated carrier from which the modulation is not recoverable without a proper code in an autocorrelation process.

Abstract: Described herein a technique for constructing a complementary MOS device on a sapphire substrate so that the surface of the device is planarized, the P-channel and N-channel devices are in substantially correct registration, the threshold voltage for the back-channel leakage effect inherent in sapphire substrate device to occur is increased, and the areas of gate oxidation are pseudo self-aligned so as to minimize overlap of the gate oxide with the source and drain regions.

Abstract: An improved multiprocessor system for providing fault isolation test upon itself is described incorporating at least a first and second digital processor, a first, second and third memory and means for switching in one memory in place of another. In addition, methods are provided for fault isolation test in a multiprocessor system and for protecting the contents of one or more selected memories.

Abstract: A memory sense circuit is described incorporating a number of field effect transistors for comparing the threshold voltage of two variable threshold transistors.

Abstract: A high speed sensing circuit is described incorporating complementary metal oxide semiconductor field effect transistor circuitry for sensing, amplifying and storing a signal indicative of the polarity of the difference voltage across two load elements. The load elements may be a pair of variable threshold transistors.