Abstract: A heterodyne CO.sub.2 optical Doppler radar comprising a ring type of traitter laser and twin local oscillator lasers which are automatically controlled to operate at a difference frequency equal to the intermediate frequency of the radar, which may be in the VHF band. The output of one of the twin lasers is injected into the transmitter laser for stabilization purposes and the output of the other of the twin lasers is heterodyned with the received target return signals to form the radar's intermediate frequency signal.

Abstract: A routing method implemented in the stored programs of a digital computer ich is programmably operated to generate the wire interconnect masks for a two level metallization automated universal array having undefined roadbeds between rows of cells comprised of identical semiconductor device basic units which are further interconnected to provide a particular integrated circuit structure. Conductor routing is provided by a computer aided design system that, among other things, carries out a route analysis process which determines in which roadbed each wire should be tentatively routed in conjunction with generating a routing density profile for minimizing congestion for a particular circuit design and when the roadbed density is exceeded, certain wires are removed under a set of criteria for routing by a pathfinder routing process.

Abstract: The placement of one or a pair of suitably biased thin semiconductor epital layers on the secondary emission surface of a multipactor device provides an improvement of devices which operate in accordance with the principle of multipactoring. A multipactor device is disclosed having a multipactor region comprised of at least one surface formed of one or more thin epitaxial semiconductor layers, the outer layer being of n-type semiconductor material consisting of, for example, gallium phosphide covered with cesium which provides an abundance of free electrons at the surface when biased in the forward direction. In one disclosed configuration the multipactor region is located in a section of waveguide while in another arrangement the region is located on the top of a post in a multipactor input cavity.

Abstract: An optical radar operating in the infrared region of the spectrum and adad to efficiently detect elongated targets such as wires. The pulsed transmitter is preferably passively Q-switched and produces optical pulses polarized in one direction. A CW local oscillator laser is locked to a frequency slightly offset from the transmitter frequency. A Brewster angle duplexer and a quarter wave plate in the transmit/receive path of the radar permit the transmitter flux to pass to a scanner and direct the orthogonally polarized echo signals to the heterodyne receiver which includes a display or alarm circuit. The transmitter and local oscillator lasers include frequency control circuits. Either wedge or ball joint type scanners may be used to scan the radar beam over a target area of interest.

Abstract: Apparatus for determining the levels or echelons of a multi-character code f a supply source, maintenance and recoverability (SMR) code for component items in a parts inventory for military equipment comprising a circular code wheel including a first circular member in the form of a disc having first and second faces respectively divided into indicia bearing sectors the outer perimeter of which identify a particular character position of the code.

Abstract: Misfit dislocation density at an InAs-GaAs interface is reduced in both InAs-GaSb and In.sub.1-x Ga.sub.x As-GaSb.sub.1-y As.sub.y superlattices grown on GaAs substrates by means of an MBE (molecular beam epitaxy) growth technique consisting of a step graded sequence of composition layers between substrate and superlattice whose composition changes in discrete concentration steps from the composition of the substrate to the composition of the superlattice.

Abstract: A method and apparatus for interleaving and deinterleaving psuedo-randomly a digital signal which is transmitted over a transmission channel is disclosed. A received bit stream is interleaved such that the order of the bits is varied in a non-random manner. The order of the interleaved bits is permutated in a pseudo-random manner and the bits are then transmitted over a transmission channel. The received bits are inverse permuted so as to return the order of the received bits to the order of the bits after the non-random interleaving step. The inverse permuted bits are then deinterleaved in the reverse order in which they were interleaved so as to reconstitute the original bit stream.

Abstract: Method and apparatus permitting a multi-module digital system, such as a puter, having built-in test hardware associated with each module, including a plurality of signal processing units to communicate over two wire circuitry not only the existence of a failure of a particular module, but also its causality. This is accomplished by means of a four state signaling circuit interposed between each signal processing unit of a particular module and a module built-in test circuit which operates once an error output is reported by a signal processing unit to provide a further four state indication of the details of the failure.

Abstract: A millimeter wavelength bandpass filter arrangement is produced by using a first dielectric waveguide as an input for a broadband signal to a ferrite circulator. This signal is delivered to a second dielectric waveguide having a bandstop filter formed therein. The bandstop filter reflects the desired bandpass frequency(s) back to the ferrite circulator where it is delivered to a third dielectric waveguide which is the output for the bandpass frequency(s).

Abstract: A termination for a VHF inverted-V half-rhombic antenna is described, consisting of a transformer terminated into a length of high attenuation coaxial cable acting as a power dissipation line.

Abstract: An output driver circuit for fast memories and microprocessors and the li The driver circuit is responsive to a binary input voltage and includes first and second signal control paths respectively coupled to a pair of series connected output stage transistors coupled between two high and low reference voltages and switched alternately between conducting and non-conducting states in mutual opposition to provide a binary output voltage substantially equal to either of the two reference voltages depending upon the binary state of the input voltage. Additionally included is an anticipatory circuit having means responsive to both an externally applied precharge signal and a feedback signal corresponding to the binary state of the output voltage which alternately predrive the transistors close to their respective conducting switching points for increasing the speed of transition of the transistors between conductive and non-conductive states.

Abstract: Apparatus and a method are shown for automatically aligning a map with fi topographic and other features therein with an underlying display on which appear electronically produced symbols which must register with the map features. The misalignment of the map is automatically sensed and measured and the positions of all of the display symbols are shifted by an amount equal to the map's misalignment, so that the map and the display information are brought into proper registration.

Abstract: Circuitry and a method for correcting errors in binary data which is stored n memory and subject to errors upon recall therefrom. The technique involves generating a redundant byte related to each original byte to be stored, storing both bytes in memory, and applying the recalled bytes to a decoder designed to correct the errors. If more than a single adjacent error per byte is expected, it is necessary to transpose the bits of the original and redundant bytes before storage so that the bits thereof alternate, and re-transpose the recalled bytes to their original sequence before application to the said decoder.

Abstract: Misfit dislocation density at an InAs-GaAs interface is reduced in both I-GaSb and In.sub.1-x Ga.sub.x As-GaSb.sub.1-y As.sub.y superlattices grown on GaAs substrates by means of a MBE (molecular beam epitaxy) growth technique consisting of a step graded sequence of composition layers between substrate and superlattice whose composition changes in discrete concentration steps from the composition of the substrate to the composition of the superlattice.

Abstract: A high voltage protection device for protecting personnel from injury or th as well as damage to radios and vehicles when a whip antenna comes in contact with overhead high voltage power lines or the like and comprises a high voltage coaxial capacitance device which is coupled in series between the upper and lower section of a whip antenna. The capacitive reactance of the capacitance device is very high at power line frequencies and relatively low at RF frequencies. The capacitance element is comprised of two concentric cylindrical conductors formed in a fiberglass shell and separated from one another by a dielectric such as polytetra fluorethylene.

Abstract: An active antenna system for an airborne high frequency single sideband receiver comprised of a shorted loop type antenna having an inductive characteristic over the frequency range of 2.0 to 10.0 MHz and which is tuned to resonance at a selected operating frequency by shunting the antenna at its feedpoint by selectively switched sets of voltage variable capacitors. Also coupled to the feedpoint is a field effect transistor which is adapted to provide radio frequency amplification. Impedance matching between the output of the field effect transistor and the input of a radio frequency receiver is further provided by a transistor configured as an emitter follower.

Abstract: A method and apparatus for frequency conversion comprising sampling an input signal having a first frequency with first time delays between samples in an input delay line, and distributing the samples of the input signal in sequence to an output delay line with different time delays between samples than the first time delays, to generate an output signal of different frequency than the input signal.

Abstract: Disclosed is apparatus for providing for increased heat transfer efficiency f a heat exchanger by separating contiguous fluid conductive channels by means of a flexible sheet fabricated from a piezoelectric polymer. An electrode pattern of predetermined configuration is applied to one or both sides of the piezoelectric sheet and an electrical signal applied thereto in order to set the sheet into a flexual resonance condition whereupon a standing wave pattern is established to not only break up the boundary layer of fluid which adheres to each side of the sheet, but also minimizing the thickness of the laminar sub-layer.

Abstract: A discharge device for use with pulsed, CO.sub.2 laser power conditioner tems, is disclosed. The device is comprised of Elkonite or molybdenum electrodes in a controlled nitrogen-xenon-oxygen environment, and having long life potential of close to twenty million discharges possible.

Abstract: A method of fabricating CO.sub.2 waveguide type lasers of the type comprising a slot formed in a broad surface of a hard ceramic material, comprising grinding the slot in a conventional surface grinding machine in two steps. The first step utilizes a coarse grinding wheel and the second a finer grinding wheel. The resultant laser cavity can produce high optical power output when provided with RF excitation.