Abstract: An electromagnetic wave ring resonator is disclosed wherein field distribution of electromagnetic waves are spatially rotated about the direction of propagation of such waves in said resonator. With such arrangement the electromagnetic field distribution rotation produces a phase difference between waves of opposite polarization senses, thereby enabling the waves to resonate with different frequencies. In a laser gyroscope the electromagnetic field distribution may be achieved by a catoptric arrangement which reduces the loss, scatter and linear birefringence associated with the ring resonator of the gyroscope.

Abstract: A programmable memory element for a programmable read only memory. The programmable memory element includes a Nichrome fusible link with a first metallization layer formed in contact with the Nichrome fusible link. An insulating layer is formed over the first metallization layer and over a portion of the Nichrome. The insulating layer is formed by first chemically vapor depositing a relatively thin layer of silicon dioxide at atmospheric pressure and then chemically vapor depositing a thicker layer of silicon nitride over the thin silicon dioxide layer, such silicon nitride layer being chemically vapor deposited in a vacuum.

Abstract: A method of preparing substantially homogeneous aluminum oxynitride powder is provided comprising the steps of reacting gamma aluminum oxide with carbon in the presence of nitrogen, and breaking down the resulting powder into particles in a predetermined size range.A method of preparing a durable optically transparent body from this powder is also provided comprising the steps of forming a green body of substantially homogeneous cubic aluminum oxynitride powder and sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron, in elemental or compound form, and at least one additional element selected from the group of yttrium and lanthanum or compounds thereof. The sintered polycrystalline cubic aluminum oxynitride has a density greater than 99% of theoretical density, an in-line transmission of at least 50% in the 0.3-5 micron range, and a resolving angle of 1 mrad or less.

Abstract: In a control circuit for a voltage-controlled oscillator including the combination of: (a) a source of D.C. power, the voltage out of such source being adjustable in discrete steps to provide a coarse frequency control signal; (b) a control loop, responsive to the signal out of the voltage-controlled oscillator, to provide a fine frequency control signal; and (c) a summer to combine the coarse and fine frequency control signals into a single frequency control signal for the voltage-controlled oscillator, an improvement is shown wherein the control loop comprises an interferometer wherein noise extant on the signal out of the voltage-controlled oscillator is degenerated by dividing a portion of such signal into a reference path, a delayed path and a parallel path, the signals in the latter two paths being processed to produce an amplitude corrected signal for combination with the signal, shifted by 90.degree., in the reference path, finally to produce the fine frequency control signal.

Abstract: A system for determining the difference in phase between a pair of radio frequency signals wherein quadrature components of one of such pair of signals are alternatively combined with the other one of such pair of radio frequency signals to provide sum and difference signals thereof. Alternative ones of such sum and different signals are alternatively coupled to an output to provide a composite signal having a phase related to the difference in phase between the pair of radio frequency signals. The composite signal is then amplified and the phase of the amplified radio frequency signal is detected to determine the difference in phase between the pair of radio frequency signals.

Abstract: A differential amplifier is provided having a pair of input transistors with first electrodes connected to a first voltage potential through a first current source, a second pair of electrodes providing a pair of input terminals for the differential amplifier, and a third pair of electrodes connected to a pair of terminals, the current produced by the first current source passing through the first and third electrodes of the pair of input transistors into the pair of terminals in a ratio related to the difference in voltage of input signals fed to the pair of input terminals and the degree of mismatch in the pair of input transistors. A selector network injects a compensation current substantially equal to the difference in the currents passing through the pair of input transistors when the voltages at the pair of inputs are equal, and which results from a mismatch in such pair of input transistors, into a selected one of the pair of terminals.

Abstract: An improved electronic circuit module retainer apparatus having interlocking, wedge-shaped components which are slotted and keyed together to allow tightening using a single screw which can be turned from the module insertion side of a module enclosure. A module retainer has a minimum of three interlocking parts which are held together by a tightening screw. A center body of the module retainer has holes for attaching it to a module or a module enclosure; it has a U-shaped channel with a square cross section and sloped ends. Each end body has a keying guide extending from a sloped end. A screw extends through a clearance hole in an end-body, then through the center body U-shaped channel and finally into a threaded hole in an opposite end body. When the screw is tightened, the end bodies slide along the sloped ends of the center body causing them to wedge the module against the module enclosure walls.

Abstract: A differential amplifier having a pair of common base transistors with emitter electrodes adapted for coupling to an input signal and collector electrodes coupled to a voltage source through a pair of resistors. A pair of clamping diodes is connected, in opposing polarity, across the collector electrodes to limit the differential voltages produced at such collector electrodes. A bias circuit is provided between the voltage source and the common base electrodes of the transistors to provide a bias voltage at the common base electrodes which is as close to the voltage of the voltage supply without biasing either one of such pair of transistors into saturation. The bias circuit includes a first resistor connected between the voltage source and the common base electrodes and, in parallel with such first resistor, second resistor and serially connected diode.

Abstract: A materials handling or processing system which includes at least two processing devices such as shredders, for example, which are subject to unexpected and relatively sudden discontinuance of operation as by clogging or other breakdown condition, and transporting apparatus for conveying materials being processed to the processing devices, the invention comprising means for detecting such breakdown in one of the devices and for consequently directing to the second device the flow of materials normally directed to the broken down device, thereby maintaining continued processing of materials without interrupting their flow through the system.

Abstract: A customizable impedance matching network for coupling a microwave transmission line to an FET. The network includes a plurality of conductive pads formed on the first surface of a dielectric substrate each pad providing in combination with the substrate and a conductor formed on an opposite surface of the substrate, a predetermined capacitance. Selective ones of such conductive pads are interconnected in parallel to form a capacitor having a capacitance related to the total surface area of such interconnected conductive pads, to provide the requisite capacitive reactance for the network. The network further includes a strip conductor formed on such first surface having a predetermined inductance per unit length and having a first end electrically connected to the network.

Abstract: A frequency measuring apparatus is provided wherein an input signal is separated into a pair of channels. A phase modulating circuit modulates the phase of the portion of the input signal fed to a first one of the pair of channels as a function of time in response to a phase modulating signal to provide a corresponding phase modulated signal. A power divider in the second one of the pair of channels separates the portion of the input signal fed to the second one of the pair of channels into a plurality of signals having phase delays imparted thereto which are proportional to the frequency of the input signal. The phase modulated signal is combined with each one of the phase delayed signals to produce a plurality of modulated signals, each one thereof having, as the envelope thereof, a signal having a frequency related to the frequency of the phase modulating signal and a phase angle relative to the phase of the phase modulating signal which is related to the frequency of the input signal.

Abstract: An impedance matching network for coupling a microwave transmission line to a field effect transistor (FET). The impedance matching network includes a resistor coupled in shunt with the FET and an inductor connected between the microwave transmission line and the resistor. The inductor is formed by wrapping a conductive wire around a post inserted into a hole formed in a support for the FET.

Abstract: A method for forming a protective layer from surface portions of a mesa-shaped semiconductor to electrically isolate a junction region formed within the semiconductor from external contaminants. A top contact electrode is formed on an upper surface of a substrate. An active region, having formed therein the junction, is formed on the bottom portion of the substrate. A support is then formed on the active region. The top contact is first used as an etching mask, and a chemical etchant is brought into contact with unmasked portions of the substrate to form a mesa-shaped structure with divergent side walls. The divergent side walls have bottom portions which include the active region and which extend beyond the periphery of the top contact electrode. The top contact is next used as an implant mask and particles are implanted in exposed portions of the side walls extending beyond the periphery of the top contact electrode to convert the exposed semiconductor material into the protective layer.

Abstract: A heater module having a cylindrical heat exchanger surrounding a central cavity and burner wherein an end manifold is covered with a layer of insulation to reduce the temperature differential between the outer annular trough of the manifold and the inner central flat disk which covers the end of the cavity. The annular trough and the disk are stamped from a unitary piece of plate steel. Without the insulation, the disk would heat to a temperature much higher than the annular trough because the trough communicates with tubes of the heat exchanger and contains recirculating liquid. By reducing the temperature differential, less strain is put on the end manifold as a result of nonuniform expansion.

Abstract: The transmission system of this invention provides for transmitting over a fiber-optic line serially sampled analog data from a plurality of channels. Each sampled analog signal has a interleaved digital pulse. A sequence of digital pulses provides synchronization data for the determination in the receiver of the output channel for each received sampled analog signal. The digital pulse associated with each sampled analog signal provides the timing for a sampling circuit to provide as an analog signal each of the sampled analog data as an analog signal to a separate channel. The digital pulses not needed for synchronization are used for digital data transmission.

Abstract: Chaff for protecting a ballistic missile from detection by radar during re-entry into the atmosphere is shown to be made up of a plurality of dart like elements, each fabricated from pyrolytically formed graphite and shaped so as to follow a ballistic path through the atmosphere upon release from said missile and to appear as a resonant dipole to interrogating signals from a radar.

Abstract: An improved combiner of microwave power out of a plurality of coaxial diode oscillators is shown to be made up of a circular cylindrical cavity dimensioned to operate in the TM.sub.020 mode at a selected microwave frequency, with such oscillators being disposed about the periphery of both end planes of such cavity and each individual one of such oscillators being reentrant at an angle of 180.degree. so as to double the number of such oscillators as compared with the number of straight coaxial diode oscillators that may be disposed about the periphery of such cavity.

Abstract: A ring laser gyroscope system uses a non-planar path and no-depolarizing Faraday bias means to achieve four-frequency differential operation. The use of the non-planar path eliminates the crystal rotator normally used to provide reciprocal bias and therefore eliminates scattering surfaces and a major cause of thermal sensitivity. The non-depolarizing Faraday means, such as a thin glass slab having a component of magnetic field along the optic axis of the laser, is used to reduce the corresponding thermal sensitivity of the traditional Faraday bias element normally implemented by a crystal such as quartz. Eliminating these major sources of drift then allows higher-order sources of drift to be corrected. Zeeman splitting of the laser gain medium is used to provide an equal amount of dispersion to each of the two counter-travelling waves of each wave pair, thus eliminating small amounts of drift due to the different phase shifts produced in the propagating waves by the gain medium.