Abstract: The processing by an infrared television system of field of view radiant emission data such as spatial, radiometric and spectral information is facilitated by apparatus and operating methods that utilize a rotatable narrow band interference filter. The filter intercepts radiant emission from a selected scene at a 0.degree. angle of incidence and at other selected angles of incidence up to 45.degree.. Distinguishing between laser and graybody targets is accomplished by continuously rocking the filter between 0.degree. and 45.degree. at the television vidicon scanning rate or some harmonic thereof.

Abstract: Optimum energy delivery in a high energy laser system is realized by intensity modulating the transmitted laser beam and demodulating the received reflected laser energy to obtain phase error signals. The error signals are used by a servo system to direct the transmitted beam. Beam intensity modulation is accomplished by angle/focus dither. In systems having relatively small slewing or scanning mirrors the angle dither is accomplished by manipulating the mirror itself. For systems having large slewing mirrors a small aperture mirror is positioned adjacent to the slewing mirror and used to impart the required dither to a small portion of the transmitted laser beam.

Abstract: A microstrip electronically scannable antenna is realized by means of an array of disc elements that are separated from a common ground plane by a dielectric medium. The center of each disc element is electronically short circuited to the ground plane. At least two pairs of diametrically opposed short circuitry switches (diodes) are connected between certain locations on the peripheral edge of each disc element and the ground plane. The polarization and phase of the reflected energy of each disc element is controlled by certain combinations of open circuited and short circuited pairs of short circuiting switches. Electronic scanning is achieved by control of the short circuitry switches, specifically by digitally controlling the forward and reverse bias of the diodes.

Abstract: An improved drain source protected MNOS transistor is realized by means of a fabrication technique that permits independent control of memory and nonmemory parameters. Self alignment of memory regions during fabrication is achieved by using nitride masking for gate oxidation. Independent control of memory and nonmemory parameters derives from a device configuration in which protected regions consist exclusively of gate oxide and silicon nitride is present only in the memory regions. Transistor radiation hardening is also achieved by elimination of the nitride layer above the device's thin silicon dioxide regions.

Abstract: A two-dimensional, AC-coupled, wide dynamic range, mosaic infrared sensor is realized by apparatus that divides incoming infrared radiation into two equal beams. Each beam is received with or without optical concentration by an infrared detector array consisting of a multiplicity of spaced, parallel columns of electrically insulated, independently wired infrared detector elements. The detector element column widths of each detector array are substantially equal to the intercolumn spaces of the other detector array and the columns of each are optically aligned with the intercolumn spaces of the other.

Abstract: Interference from polarized signals is minimized by controlling the polarization of antennas having orthogonal dipole radiating elements. The antenna system utilizes microwave hybrids and phase shifters in a coaxial cable feed circuit that divides the power between horizontal and vertical dipole radiating elements. The circuit provides a variable antenna polarization that can be controlled to discriminate against interfering signals having any given polarization characteristics. Coaxial double folded baluns connect feed circuits to the dipole radiating elements and provide proper phasing and impedance transformation for efficient dipole operation.

Abstract: The detection and indication of a probe contact to metalization and to junctions on chips during microcircuit analysis is achieved by means of a circuit comprising a complementary MOS transistor logic circuit and light emitting diodes (LEDs). A polarity switching circuit provides probe contact indication in response to "0" and "1" logic levels for both forward and reverse bias conditions. Other switching circuits provide sensitivity level selection and the transfer of probe output to an alternate microcircuit analysis device. An auxiliary sound indicator is connected in parallel with the visual LED indicators. Probe assembly capacitance is minimized by a plexiglass insulator that inserts a fixed capacitance between each probe contact.

Abstract: Ellipsometric parameters for a given structural member surface area are obtained by scanning the structural member surface area at an oblique angle with a polarized monochromatic light beam and receiving the reflected light beam with a rotating analyzer. The rotating analyzer outputs are detected at its 0.degree., 45.degree. and 90.degree. azimuth orientations by a photodetector. The photodetector outputs can be plotted in their proper relationship to the scanned surface area boundaries to provide maps useful in nondestructive testing and other applications. Equations are provided that permit the conversion of the photodetector outputs into ellipsometric physical parameter values for refractive index, absorption coefficient and material thickness. Scanning in one embodiment is accomplished by a structural member holding device that can be simultaneously rotated and vertically translated.

Abstract: Sidelobe suppression in directional beam forming antennas is accomplished by means of a spatial filter. The filter geometry consists of flat layers of high dielectric constant dielectric separated by air or other low dielectric constant dielectric substance. The filter is placed directly over the antenna radiating aperture and its dielectric materials have dielectric constant and thickness values that effect full transmission of beam power in a selected beam direction and substantial rejection of it in other directions.

Abstract: The laser target simulator of the invention comprises two point sources of light energy (LEDs) aimed at a section of concave spherical mirror which collimates the light energy and projects it across the full aperture of a laser seeker. One of the point sources of light energy is positioned on the laser seeker boresight at the mirror focal point. The other is positioned in spaced adjacent relationship to it and is rotatable about the laser seeker boresight. A CW light source is positioned coaxially to the boresight point source of light. The simulator also includes light source control circuits that make it possible to test the various operational modes of the laser seeker including tracking rates and accuracies, acquisition logic, laser pulse coding, and false target rejection.

Abstract: Alignment of the optical, mechanical and electrical axes of an antenna system is accomplished at short range by means of a test antenna having an aperture that is approximately 20 percent greater than the aperture of the antenna being aligned. The test antenna is positioned to receive or transmit radiation from/to the antenna being aligned at a distance of less than D.sup.2 /.lambda. where D is the diameter of the antenna aperture and .lambda. is the wavelength of the antenna operating frequency.

Abstract: Two waveguide structures are coupled by connector members that are slideably engaged to one waveguide and adaptable to fixed engagement with the other. Tapered threaded locking pins are threaded through a portion or extension of the waveguide structure that accommodates the slideable end of the connector members. The tapered end of each locking pin engages a tapered recess in a connector member. Longitudinal translation and fixed coupling of the two waveguide structures is achieved by screwing the tapered ends of the locking pins into full registration with the tapered recesses in the connector members. The connector members can be rotatable about the locking pins and partial retraction of the locking pins permits ready disengagement of the connector members from the other waveguide.

Abstract: Each phase of the power input circuit in a three-phase electrical system is coupled to a sensor by means of a pick-off transformer. Each sensor has an overcurrent detection circuit comprising a slow response filter, an operational amplifier, and a comparator and an undercurrent detection circuit comprising a fast response filter, an operational amplifier and a comparator. A fourth overcurrent detecting sensor is coupled to a selected system feed circuit. A C/MOS logic circuit responds with a "high" state output when any number of sensor network outputs go to the high state. The output of the C/MOS logic circuit is filtered by a slow response filter and is used to trigger an actuating circuit that operates a standby breaker in the system input circuit.

Abstract: A radar system is operated in a manner that provides determination of the coincidence of radar signal polarization with the major axis of a target of unknown aspect angle. This information so obtained can be utilized to enhance radar signals or to improve target identification capabilities. One approach comprehends transmitting circularly polarized radar signals and receiving return signals on a linearly polarized receive antenna. By varying the polarization of the receive antenna over a 180.degree. range signal maxima and minima are detected that correspond to alignment of the target's major axis with the radar signal E and H field vectors. The method can also be practiced by transmitting linearly polarized radar signals, the polarization of which is also varied over a 180.degree. range.

Abstract: A surface acoustic wave bandpass filter having a flat frequency response in the passband and an exponentially decaying out-of-band response is realized by designing its transducer electrodes to have an appropriate number of discretely apodized interdigital fingers. The apodization or overlap coefficients H.sub.o (N) of adjacent fingers are determined from an analytically derived expression that incorporates factors for the filter time length parameter, the filter center frequency, bandwidth, transition bandwidth falloff, and a ripple reduction parameter.

Abstract: The particular anisotropy of a specific propagation surface orientation on a single crystal lithium tantalate substrate member is utilized to achieve low diffraction, low spurious response surface acoustic wave (SAW) propagation. The preferred embodiment utilizes a propagation surface that substantially coincides with a plane defined by the Euler angles Lambda = 0.degree., Gamma = 166.65 (+0, -0.3).degree., and Theta = 90.degree..

Abstract: Television picture "wash-out" is eliminated by means of a signal processing circuit that adapts and enhances the video gray scale of television pictures to compensate for adverse lighting conditions in the viewed area. The circuit approach comprehends processing the video signal in terms of picture area. Each step on the gray scale from black to white is assigned a percentage of the total picture. The circuit comprises a plurality of comparators each working at a different threshold level. Each comparator is followed by an integrator and a feedback circuit that adapts that comparator sense level to the incoming signal. The video signal is processed in a way that always produces certain assigned ratios of black, white, and/or shades of gray.

Abstract: High reliability, very high slewing rates and fast settling times are realized in an operational amplifier circuit having a single externally controllable gain stage and an input stage that utilizes complementary bipolar transistors and dielectric isolation. The input stage comprises the parallel arrangement of two emitter-follower composite transistors. Each emitter-follower composite transistor consists of the parallel arrangement of two series connected NPN transistors and two series connected PNP transistors. The transistors are connected so that the base current of the PNP transistors supplies base current to the NPN transistors. Dielectric isolation is provided by means of SiO.sub.2.

Abstract: In an AMTI radar having digital doppler processing, adaptive clutter and interference rejection is achieved by automatically adjusting antenna phase and amplitude weights to trim for uncalibrated errors and to put nulls in the antenna receive patterns in the direction of the source of interference or jamming signals. Antenna weights are initially chosen to achieve an optimum signal to clutter ratio. The radar receive signals are averaged over many range cells, filtered and summed by adaptive processor circuits. Feedback loops adjust the antenna weights to minimize the summed output. The circuits effect this by mechanizing the steepest descent algorithm.

Abstract: Clutter cancellation between adjacent channels of a multichannel synthetic aperture AMTI radar is accomplished by delaying signals from the forward channel to coincide with signals from the aft channel and subtracting the outputs. Adverse effects from unknown, uncalibrated and time varying parameters are compensated for by adjusting the phase and amplitude of the aft channel coherent receiver output in response to the complex multiplier signal .omega.. The synthetic aperture processing circuit outputs of each channel are averaged over many range cells and summed to determine clutter magnitude. The complex multiplier signal .omega. is made to minimize the clutter magnitude by means of a steepest descent algorithm. A mathematical expression relating the complex multiplier signal .omega. to clutter magnitude for optimum clutter cancellation is developed and a circuit is provided for mechanizing the process.