Abstract: An inherently rugged multi-color dot matrix impact printer having a yoke type optical code detector assembly mounted on the neck portion of an impact dot matrix print head through which a multi-colored print ribbon passes. The print ribbon is configured in alternating vertical segments of selected colors of ink which have top and bottom photo-optical code regions on the outer edge of the ribbon. Coding comprises the presence or lack of an aperture in the form of a hole which is adapted to pass light therethrough and which is aligned with each ink segment. The yoke additionally includes upper and lower light emitter/sensor pairs for sensing the coded aperture pattern to control the presence of a predetermined colored segment of printing ribbon in front of the print head.

Abstract: A millimeter wavelength oscillator combining a mechanically tunable resonating cavity oscillator element with an electronically tunable solid state diode element provides a basic stable steady wave energy source with fine-tuning capabilities not possible with a resonating cavity oscillator alone, and with an apparatus structure which is light in weight, compact, mechanically sturdy, and with easily accessible and quickly replaceable component parts.

Abstract: A continuity detecting apparatus for testing the continuity of conductors in damaged cables, comprises at least two test cables, each having a proximal end and distal end. The distal end of each test cable is adapted to be electrically connected to a respective end of a conductor to be tested. The apparatus includes a detector adapted to provide an output signal in response to an input signal exceeding a predetermined threshold level, a device for connecting the proximal end of at least one of the cables to a signal source and the proximal end of another of the remaining cables to the detector, and an indicator responsive to the output signal for providing an indication of current flow through a conductor connected between the distal ends of the one and the other cables.

Abstract: An integrated circuit tunable cavity oscillator for extremely high freque operation in image line waveguide. The oscillator includes a metal base with a cylindrical bore, a dielectric or semiconductor waveguide mounted atop the metal base and having a bore which is continuous with the metal base bore. A Gunn or IMPATT diode is assembled in the metal base bore on top of a drum which is urged upwards toward the waveguide bore by a spring located behind the drum. From above, cavity tuning means including a top disk and a threaded screw cover the waveguide bore and push the diode into the metal base bore to define the cavity height of the coaxial cavity of the oscillator. The waveform, which is set up in the recessed cavity in the metal base, is launched into the waveguide. Thus, a ruggedized, low cost, tunable (by a tuning screw) and low weight oscillator for millimeter wave image line or microstrip operation is obtained. Furthermore, the oscillator diode and cavity defining hardware are easily replaceable.

Abstract: A method and apparatus is disclosed for automatically and repeatably measng the effectiveness of jamming applied against a communications link. The method is machine performed, free of the need of listener personnel, and the recording and scoring tasks required in conventional methods. Using a ratio of auto and cross-correlation functions, a number is produced (CCI Index) which is the desired measure of jamming effectiveness. The CCI Index is a standardized value which indicates jamming effectiveness in any type communications link regardless of equipment or type of modulation in use. The Index, rapidly obtainable, can be used to pinpoint which jamming technique might be most advantageously employed, and by precisely how many db it would be superior.

Abstract: A computer process for the automatic layout of a multiport, two-dimensional icrocircuit. The program provides for improved cell placement and power distribution while minimizing the overall chip area dimensions. The power distribution layout provides for the supply of power to cell rows which is independent of the peripheral power routes.

Abstract: A method and means for producing a zero temperature coefficient for providing frequency stabilization as well as adjusting the frequency at a particular temperature of a dielectric resonator comprised of a cylindrical dielectric resonator element mounted on a substrate and having a dielectric disc affixed to the top of the resonator element. A zero temperature coefficient is obtained by selectively choosing the thickness of the dielectric disc depending upon the temperature coefficients of the constituent material of both the disc and resonator element. The operating frequency at a given temperature is furthermore adjusted by including two mutually contiguous patterns of metallization on the top surface of the resonator element and the bottom surface of the dielectric disc and thereafter rotating the disc so that a predetermined percentage of overlap between the two patterns exists.

Abstract: A coded linear array antenna comprised of a plurality of multiple element barrays, each providing sin mx/sin x patterns which are combined, i.e. summed into a composite pattern by having the subarrays commonly connected to a signal summation means. Each subarray is comprised of multiple elements which are respectively spaced equidistantly apart and positioned symmetrically on either side of a common array axis center or axis of symmetry and wherein the individual antenna elements of each subarray are positioned at an i.sub.th location according to the normalized equation ##EQU1## where i=1, 2, 3, . . . h, n.sub.m defines the maximum number of elements in the length or aperture of the composite array, h is the number of elements in the respective subarray, and n is proportional to the element spacing of the respective subarray.

Abstract: High power optically activated switches of the semiconductor type utilizing broadbanded flashlamp as the source of light for rendering the semiconductor conductive and thus close the switch. In order that the conductivity of the semiconductor when in the "on" state be uniform over the load current carrying cross-section thereof, the semiconductor is treated to produce a tapered density of trapping or re-combination centers therein, with the density being a maximum at the semiconductor surface which faces the flashlamp. Several novel configurations of these switches are shown, including reflectors for concentrating the flashlamp output on the semiconductor, and a plurality of semiconductor switches all activated by a single light source, as well as liquid cooled semiconductors.

Abstract: A millimeter-wave electronic scan, phased array antenna in a slotted dielectric waveguide having a semi-insulating core and at least one semi-conducting epitaxial layer. A controller affixed to the epitaxial layer is used to apply a bias voltage thereby varying the conductivity of the layer and influencing wave propagation in the guide to effect beam scanning.

Abstract: A crystal oscillator, including two crystals of unequal acceleration sensvity magnitude and mounted such that their respective acceleration sensitivity vectors are aligned in an anti-parallel relationship, further includes at least one electrical reactance, such as a variable capacitor, coupled to one of the crystals for providing cancellation of acceleration sensitivities. After the acceleration sensitivity vectors of the two crystals are aligned anti-parallel, the variable capacitor is adjusted until the net or resultant acceleration sensitivity vector of the pair of resonators is reduced to zero. A second electrical reactance, such as a variable capacitor, is utilized as a tuning capacitor for adjusting the oscillator's output frequency to the desired value, while maintaining the cancellation of acceleration sensitivities.

Abstract: A dual Gunn self-oscillating mixer is shown which can mix signals in the range substantially without introducing any noise and with high input signal power handling capacity and with higher output mixed signal power than conventional, owing to boosted power from more than one microwave cavity. The device is comprised of two cavities and connected by a 180.degree. phase shift coax line for injection locking, or a cavity wall hole in yet another embodiment. The device handles larger power levels without burning out as compared to conventional type mixer devices such as Schottky barrier diodes having nearly 30 times the burnout susceptibility.

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: A high power high frequency field effect transistor is achieved with a vertical structure of gallium arsenide including a semi-insulating substrate, a conductive layer over the substrate, a narrow-central post having small metal gate electrodes on each side, metal drain electrodes on the conductive layer spaced from the central post and a metal source electrode supported on the central post. A deep channel around the post separates the metal drains, gates and source. Increased power is obtained from a cellular unit including two parallel source stripes, four gates and three drains. The drains are connected together by the conductive layer and a drain pad at one end, and the gates are connected at the other end by a gate pad on an outer region of the substrate. The gate connections to the pad are isolated from the conductive layer by a bridge over a space etched in the lower layer. A method for fabrication of this structure is also provided.

Abstract: Expanded multilevel noise codes are generated of a type termed "code mates" aving autocorrelation functions which, upon detection in a matched filter, provide an impulse autocorrelation function. More particularly, expanded multilevel code mate pairs are generated by butting two multi-bit codes comprising a mate pair wherein one of the codes in each expanded mate pair comprises a code having a larger amplitude than the other code and whose position is mutually transposed in the expanded mate pairs and further wherein one of the butted codes is the complement or negative of one of the original or base code mates.

Abstract: Improvement of resonator circuit parameters, unwanted mode suppression, and the frequency-temperature characteristic of a crystal resonator is provided by a doubly cut crystal resonator plane having at least one major face including a cylindrical contour, the axis of which is parallel to the direction of the projection of the eigenvector (the normal coordinate) for the desired operating mode. The cylinder axis is at an angle to the doubly rotated electrical axis such that the fast shear "b" mode is suppressed while the slow shear "c" mode is unaffected. The radius of the cylinder is selectively chosen for altering the frequency-temperature characteristic.

Abstract: A millimeter-wave cut-off switch in a dielectric waveguide having a semi-insulating core and a semi-conducting epitaxial layer. A controller affixed to the epitaxial layer is alternately switched to vary the conductivity of the epitaxial layer thereby influencing wave propagation in the waveguide. When the waveguide is properly dimensioned such that the operating frequency lies in the high-loss section near the cut-off frequency on the loss vs. frequency characteristic curve, an applied reverse bias voltage produces a switching function in the loss characteristics associated with the wave propagating in the guide thereby resulting in low-loss propagation.

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: A high voltage multiplexer comprising as the switching elements for each nnel thereof a pair of series connected double diffused metal oxide semiconductor transistors connected source-to-source to obtain very high `off` resistance, with optical links comprising LEDs to switch the pairs of transistors `on` and `off`. A logic chip controls the switching of the transistors in accordance with externally applied signals. Circuitry is provided for rapidly discharging any voltage remaining on the gate-to-source capacity of the series-connected transistors upon the switching `off` of any channel.

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.