Abstract: Automatic responsivity control for an array of infrared photodetectors is provided without additional hardware such as a beam chopper or a reference object of known irradiance. The requisite modulated reference signal is provided instead by uniformly modulating the bias voltage applied to each of the plurality of photodetectors in the array. Photodetectors having different responsivities respond to the same bias modulation differently to produce a superimposed sinusoidal component in the photodetector output current which is used to compensate for differences in responsivities of the individual photodetectors.

Abstract: An optically scanned monolithic focal plane array includes an on-chip aperture corrector interposed between the photodetector output register and the multiplexer, thereby providing data to the aperture corrector in an order parallel to the direction of optical scan, advantageously eliminating any requirement of additional hardware for demultiplexing, memory or timing functions. The desired transfer function is achieved by providing a supplementary source of charge flow in addition to the photodetector signal, the supplementary charge flow being reduced in response to each signal charge packet at first and second intervals which are advanced and delayed respectively with reference to each corresponding signal charge packet by a selected interval. This reduction is proportional to a portion p of the signal charge packet which is determined by adjustment of bias voltages controlling injection of supplementary charge without requiring a charge splitting mechanism.

Abstract: Apparatus is provided comprising two antennas generally oriented in non-parallel directions such that their effective apertures are different relative to received radiation, each antenna being individually connected to two integrated optica spectrum analyzers. Switching means is provided which alternately switches signals provided by the two antennas between the two integrated optic spectrum analyzers. A microcomputer is connected to the outputs of the two integrated optic spectrum analyzers for comparing the relative intensities of signals received therefrom and provide a signal indicative of the direction of arrival of radiation received by the two antennas.

Abstract: An optically scanned monolithic focal plane array includes an on-chip aperture corrector interposed between the photodetector output register and the multiplexer, thereby providing data to the aperture corrector in an order parallel to the direction of optical scan, advantageously eliminating any requirement for additional hardware for demultiplexing, memory or timing functions. The desired transfer function is achieved by providing a supplementary source of charge flow in addition to the photodetector signal, the supplementary charge flow being reduced in response to each signal charge packet at first and second intervals which are advanced and delayed respectively with reference to each corresponding signal charge packet by a selected interval. This reduction is proportional to a portion P of the signal charge packet which is determined by a charge splitting mechanism.

Abstract: Various techniques for merging charge into and splitting charge from CCD's are described. Specifically disclosed in detail is a racetrack shaped charge coupled device (CCD), provided with special input and output stations operating on the principle of progressive charge read in and readout. During read in (which is a special case of charge merging), charge is injected in the direction of prevailing charge flow in the main channel of the CCD, with the injected charge packets being transferred laterally into the main charge stream while being stepped forward in the channel. During readout (which is a special case of charge splitting), charge is transferred from the main channel to an auxiliary channel through a plurality of interconnecting ports and, as during read in, transfer of a given charge packet takes place over a time period during which the charge packet is stepped forward in the main channel through several storage sites.

Abstract: A dye laser is disclosed wherein a plastic disk containing laser dye is moved within a cylindrical race relative to a stationary pumping laser beam such that the pumping beam effectively scans the surface of the laser disk along a cycloidal path as the disk rolls along the race surface. The cycloidal illumination pattern on the disk enables a significantly increased amount of laser material to be exposed to the pumping beam.

Abstract: Circuits are described which optimize the signal-to-noise ratio of a signal amplifier by means of active circuits which simulate low-noise resistors. When such "absorbers" or "desorbers," as they are termed, are used in amplifier circuits with signal sources characterized by equivalent thermal noise resistances they provide low-noise means for matching the source and amplifier for optimum noise behavior. In accordance with the invention therefore, it is possible to utilize active circuit elements such as transistors or op-amps in such a way as to realize amplifiers which have better noise figures than conventional amplifiers fabricated of the same circuit elements.

Abstract: A spark timing control circuit for an internal combustion engine, includes a speed band selector circuit which responds to an electrical signal indicative of engine speed and provides an output signal indicative of which of a plurality of speed bands is occupied by the engine speed. Spark timing information for each speed band is stored in a memory as a first word in units of angular rotation of the engine for the heaviest engine operating load, and a second and third words indicative of the slope of straight line approximations to the curve of engine load plotted against advance in said angle units. A build up circuit responds to an electrical signal indicative of the engine operating load and computes from the second and third words a build up word which is added to the first word in an accumulator so as to derive an accumulated word in said angle units indicative of the desired spark timing.

Abstract: High energy alkaline storage batteries exhibiting exceptionally long storage life are fabricated from cells which show no sign of deterioration after more than 3000 cycles at 80% depth of discharge. The exceptional characteristics of these cells are attributed to improved separators fabricated from zirconium oxide cloth reinforced with organic polymeric materials.

Abstract: An electrically excited laser is disclosed wherein a laser gas is caused to flow along a gas flow channel and through an excitation region thereof in which an electric discharge is established between an anode and a cathode disposed substantially flush with respective opposing walls of the gas flow channel, and wherein an electron beam is introduced into the excitation region along a direction parallel to the discharge direction. A shield arrangement is provided immediately downstream from the laser excitation region to confine the discharge to the region directly between the anode and the cathode. The shield arrangement includes a plurality of planar electrically insulating rack members disposed across the gas flow channel in respective spaced planes parallel to both the direction of the discharge and the gas flow direction, and a plurality of planar shelf members carried by the rack members and oriented with their board surfaces transverse to the rack members.

Abstract: In an ignition circuit for a split section gas discharge laser having a common anode, a positive sustaining voltage is applied to the common anode while independent negative starting potentials are applied through high resistances to cathodes at either end of the laser tube which are grounded through diodes to prevent shorting of the ignition voltage source while providing a return path for the sustaining voltage source. The cathodes are immediately brought to ground potential upon ignition so that gas discharge in each of the two sections may be independently ignited while mirrors at either end of the laser tube are maintained at or near ground potential during operation of the laser after ignition.

Abstract: A waveguide switch having four RF ports in coplanar relationship and incorporating four waveguide transmission lines in a single rotating mechanism on two levels, the rotating mechanism being driven by an electromagnetic stopper motor or the like to efficiently function as a multiple redundant waveguide switch.

Abstract: A waveguide filter is herein described that employs a resonator ordering which allows a direct realization of all canonical couplings while retaining the advantages of a standard dual mode filter, the filter including a reflective plate in one end cavity and both input and output ports in the other end cavity, where one of the ports is a shunt port in a sidewall of the cavity structure and the other port is a coupling slot in the outer end wall.

Abstract: A two-port-to-three-port waveguide switch comprising two single pole double throw waveguide switches integrated so that one of the terminals of each switch has a common junction.

Abstract: A phased array antenna system is disclosed for scanning a narrow beam over a limited angular sector with near optimum performance while using the minimum number of active elements. An input corporate feed is coupled to a "thinned" array of phase shifters. Each phase shifter is coupled to one of a plurality of lossless periodic matrix sub-array feed networks. Radiating elements are coupled in periods such as three elements per period. The output of each phase shifter is selectively coupled to the array of radiating elements within its period and to elements in adjacent periods as well. Such an array permits a plurality of overlapping main beams having low side lobes and grating lobes.

Abstract: There is herein described a device useful to store a frame of low-intensity optical information over a wide spectral range or useful as a real-time light valve in visible to infrared conveter application. The device basically includes either a storage mode liquid crystal or a dynamic scattering or a field-effect liquid crystal, and a semiconductor diode array substrate wherein an insulating film with an array of conducting windows separates the liquid crystal from an active region in the substrate. A separate diffused junction is disposed in the active region adjacent each of the windows, the latter being adapted to both reflect incident light energy and conduct electrical current.

Abstract: There are herein described microwave devices that are mounted at the output ends of circularly polarized horn antennas of a microwave antenna array. The devices act as coupling compensators between the horns, and also function as singular or dual polarization trimmers to create very low axial ratio circularly polarized antenna array patterns through a broad angular range. In each of these devices, a parasitic element is disposed on a planar substrate that is orthogonally positioned with respect to the direction of propagation from the horn antennas.

Abstract: There is herein described a support structure for antennas, optical systems and the like which are generally subject to non uniform dimensional changes due to temperature variations and gradients in the support structure material, the invention overcoming such dimensional changes by combining the use of a material having a low coefficient of thermal expansion and the use of a heat pipe as an integral part of the aforementioned structural member for isothermalization, to reduce the distortion resulting from residual non-zero coefficient of thermal expansion.

Abstract: The specification describes an improved III-V compound solar cell structure and fabrication process therefor wherein a P-type layer of gallium aluminum arsenide is epitaxially grown on an N-type gallium arsenide substrate to form a P-type region and a PN junction in the substrate. Controlled amounts of beryllium are introduced into both the epitaxial layer and the substrate, either during epitaxial growth or by using beryllium ion implantation techniques subsequent to the P-type epitaxial growth step. The homojunction-heterostructure device thus formed exhibits improved power conversion efficiencies in excess of 17%.

Abstract: Brazing alloy on detailed aluminum parts is formed in an exact pattern of the joints to be brazed. An aluminum sheet having brazing alloy coated on one or both sides (e.g., a brazing sheet) is plated with electroless nickel and electrolytic copper which are etched by use of a photoresist mask into a mask which outlines the pattern. The brazing alloy coating is then chemically milled to form the exact pattern of the joints. Parts are then assembled and dip brazed to form the completed brazed unit.