Abstract: A vertically polarized array comprised of both bottom fed and top fed conurations having a driven element comprising at least one but, when desirable, two generally horizontal wire conductor segments of a length substantially equal to one half the operating wavelength of the array and with the ends of the half-wave conductor segments being connected to or extending into generally vertical quarter wavelength wire conductor segments. In a bottom fed configuration the feedpoint is at the bottom end of one vertical quarter wavelength conductor segment while in a top fed configuration one vertical quarter wavelength segment comprises a quarter wavelength of coaxial transmission line having one end configured into signal isolation means, comprising a cable choke, while the feedpoint is located at the other end.

Abstract: Silicon wafers are imprinted with microelectronic circuit patterns by first ithographing the outlines or peripheries of all circuit features of a given wafer level by means of a narrow line formed by direct-writing electron beam lithography utilizing a positive electron resist, then using proximity photoprinting to complete the lithography of that level using a positive photoresist and a photomask with oversized opaque areas so that the pattern edges on the wafer exposed to the flux passing through the photomask will fall within the peripheral lines formed by the electron beam.

Abstract: A circuit for biasing a solid state crystal used as a radiation detector in hich the passage of the initial gamma ray pulse from the explosion of a nearby tactical nuclear weapon is utilized to temporarily remove the bias from said crystal for a time sufficient to permit the fast neutron pulse from the same explosion to pass by without permanently damaging the counter crystal. The circuit comprises an RC circuit between the bias supply and the crystal with a reverse biased diode across the capacitor.

Abstract: The frequency-temperature characteristic of the piezoelectric resonator in a temperature compensated crystal oscillator is adjusted by the inclusion of an equivalent inductive reactance connected in series with a piezoelectric crystal resonator coupled to an oscillator circuit, with the equivalent inductive reactance being realized in the form of an inductorless Maxwell type bridge circuit containing the resonator. Such an arrangement provides a much larger variation in the temperature-frequency characteristic than can be realized with a conventional capacitor in series with the piezoelectric resonator.

Abstract: Apparatus for implementing a multi-color printout capability with respect to a dot matrix printer and the like. The apparatus is comprised of an ink reservoir system which includes individual ink reservoirs for replenishing ink of a selected color from a reservoir to individual sections of ink transfer material. The sections are mounted in tandem pairs on elongated ink transfer material holding members which are reciprocally moved linearly back and forth beneath the print head and across the face of a printing medium by a solenoid actuated cam. Each reservoir is continuously in contact with respective section of ink transfer material.

Abstract: A radiochromic optical waveguide dosimeter is protected from the adverse perature effects of exposure in the desired operational temperature range of -40.degree. C. to +60.degree. C. by flattening the round plastic tubing to be used for the fabrication of the dosimeter until the tubing attains an elliptical cross section and then fabricating the dosimeter from the tubing having the elliptical cross section.

Abstract: A programmable optical sensor is formed by coupling a proximity focused channel intensifier tube to a silicon target vidicon. The photocathode is gated by a first time programmed voltage and the gain of the microchannel plate is also controlled by a second time programmed voltage. The second voltage is less than 1,000 volts permitting the use of solid state circuitry.

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: A control processing method and apparatus for dot matrix printers which are ubjected to relatively high levels of vibration and shock. Vibration and shock are detected and, in the event that a known safe vibration or shock level is exceeded, print line data being fed alternately to the print head from a pair of data print buffers coupled to the output of a logic data input buffer are inhibited while the input buffer temporarily stores the incoming data. Drive pulses applied to the stepper motor used to move the print head carriage are simultaneously stopped. When the detected level falls below a set threshold indicative of a safe operating level, normal operation is resumed with the print data again being fed from the input buffer to the print line buffers which are reactivated along with the carriage stepper motor.

Abstract: An acoustic surface wave device is configured as a bandpass filter. The device employs two interdigital transducer pairs for input and output. Each transducer pair has a slant finger geometry. The fingers are electrodeposited into grooves etched into the substrate. The grooves are deeper at the high frequency side of the substrate. The grooves enhance the electromechanical coupling of high frequency components and thus provide a flatter amplitude response curve.

Abstract: Noise codes are generated of a type termed "code mates" having correlation unctions which, upon detection in a matched filter, provide an impulse autocorrelation function. More particularly, code mate pairs of at least two code bits each are generated and shown, for purposes of illustration, utilized in a communications system and wherein one code mate is comprised of two signal bits of first and second or opposite polarity, one bit of which has a larger amplitude than the other bit and wherein the other code mate is comprised of two signal bits of said second polarity, one bit of which has a like larger amplitude than the other bit.

Abstract: An acoustic surface wave device is configured as a bandpass filter. The device has similar groups of sinusoidal corrugations cut into portions of both the top and bottom surfaces of an otherwise flat piezoelectric substrate. A pair of input interdigital transducers is located upon one end of the top flat surface of the substrate. A similar pair of output interdigital transducers is located on the bottom flat surface of the substrate at the end opposite the input interdigital transducers. When an input RF spectral signal is applied to the input interdigital transducers, the transducers convert the electrical signal spectrum to a surface acoustic wave spectrum. When the surface acoustic wave spectrum strikes the corrugations cut into the top surface of the substrate, the corrugations selectively scatter certain spectral components into bulk vibration.

Abstract: A chemical sensor matrix is provided for sensing the presence of chemical agents by chemo-electronic means. The chemical sensor matrix is comprised of a plurality of resonators embedded in a single monolithic piece of piezoelectric crystal. The resonators are arranged in rectangular row and column configuration including m rows and n columns, each of the resonators being separated from its neighboring resonators by distances such that the resonant energies do not overlap. Each of the resonators is coated with a different chemical substance to be sensitive to a chemical agent to be detected so that when the chemical substance reacts with the chemical agent, the frequency f.sub.mn changes. Each of the rows of resonators bears a metallic electrode stripe for that row, and each of said columns of resonators bears a metallic stripe for that column. The electrode row stripes are positioned on the top surface of the crystal, and the electrode column stripes are positioned on the bottom surface of the crystal.

Abstract: An apparatus and a method which permits a plurality of master stations to be attached to a communications channel and to provide an arbitrating mechanism within each master by which one master station is designated as in control of the communications channel. The method overcomes the single point failure of the true master slave station by providing redundant masters. Furthermore, each station in the network is polled by a grant transmission at a constant interval of time irrespective of which master is in control of the bus to assure efficient utilization of the bus.

Abstract: This tool permits rapid and easy stripping of the outer insulation from cxial cables or the like. The end of the cable to be stripped is first inserted into a gauging hole in a block of insulating material. A pair of blade-shaped electrical heating elements are clamped against opposite sides of the cable at the mouth of the hole and the cable rotated to form a thermal circumferential cut in the outer insulation. The cable end is then placed in another jig with a V-shaped groove therein and a blade-shaped heating element at the bottom of the groove. A second similar heating element is arranged above the groove and the cable. These two heating elements produce diametrically opposed longitudinal cuts in the insulation, after which two pieces of the insulation can be easily removed.

Abstract: A beamforming system for a linear phased array antenna system which can be sed in a monopulse transceiver, comprising a pair of series connected parallel plate constrained unfocused lenses which provide a suitable amplitude taper for the linear array to yield a low sidelobe radiation pattern. Digital phase shifters are used for beam steering purposes and the unfocused lenses decorrelate the quantization errors caused by the use of such phase shifters.

Abstract: An electro-optical interface unit is shown for interfacing an all-optical telephone to a conventional electrical-metallic-type telephone communications system, having conventional electrical subscriber units, switching, and supervisory systems. An overall all-optical telephone communication system, of which an all-optical telephone is a part, is envisioned. The disclosed system makes use of optical-acoustic-electrical types of transducer elements, light modulators, and optical junctions, among other novel elements.

Abstract: A method and apparatus for pressing magnetic powder in a toroidal-shape we in a radial magnetic field. A magnetic flux is produced and carried by a die rod through the axial center of toroidally-shaped magnetic powder. An annular portion coaxially surrounding the die rod and magnetic powder is connected to a yoke member which carries the magnetic flux back to the magnetic flux producing means. This completes the magnetic circuit, and creates a radial magnetic field across the toroidally-shaped magnetic powder between the die rod and the annular portion. This radial magnetic field aligns the granules of the toroidally shaped magnetic powder during pressing.

Abstract: A filter reflection image guide oscillator and a line scanning device. The device includes a brass metal heat sink base on which a dielectric waveguide is mounted. A resonant cavity is defined in the dielectric waveguide and an oscillator diode, Gunn or IMPATT, for example, is located in the resonant cavity. The resonant cavity is enclosed by a metal cover with a post which is made to extend into the resonant cavity to contact one electrode of the oscillator diode. The top surface of the waveguide includes a perturbation surface consisting of parallel and spaced metal stripes which are laterally positioned along the length of the waveguide. The spacing of the metal stripes defines the function performed by the device. When the stripes are at 1/2.lambda..sub.z spacings (.lambda..sub.z is the guide's longitudinal wavelength), a filter reflection image guide oscillator is provided and the perturbation surface is non-radiative. Only a small portion of the energy radiates out of the front of the waveguide.

Abstract: An electronic varactor tuner is integrally combined with a mechanically tuned Gunn oscillator to provide an increased tuning range in a light weight, compact, rugged combination with easily and quickly replaceable components.