Abstract: An apparatus and method for processing optical beams designed to adaptively spatially threshold or filter an intensity histogram spectrum for re-transformation to a two-dimensional thresholded optical output. Such apparatus and method is used in optical computing and logic processing to selectively pass only certain light intensities, thereby blocking undesirable background noise while passing the desired signals. An incoming histogram light beam, containing an optical position distribution corresponding to the intensity distribution of an original optical beam, is split into first and second beams. The first beam is directed at a light detector array which transforms the optical position intensities of the first bema into directly proportional electrical signals.

Abstract: An antenna system includes an array of microstrip antenna elements wherein each of the elements includes two or more radiators. Electromagnetic signals are coupled from an input terminal of each element via one or more circulators which allow for application of an input signal to a first of the radiators followed by rerouting of respective signals to the next radiator. The radiators are turned to radiate at successively higher portions of the electromagnetic spectrum. By virtue of reflections of higher frequency radiation from a radiator tuned to a lower portion of the signal spectrum, each radiator radiates only that portion of the signal spectrum falling within the bandwidth of the radiator. By using three radiators, each antenna element is capable of radiating a signal spectrum three times as wide as are the bandwidths of a single radiator. Included within the antenna system is one or more power dividers to form one or more beams of radiation.

Abstract: A channel adaptive active sonar is disclosed, wherein the sonar transmit waveform is adaptively selected in accordance with the measured sonar channel scattering function to reduce the response of the sonar to unwanted reverberation while preserving the response to signal returns. As a result, the sonar target detectability is improved over sonar systems which do not adapt to the variable properties of the ocean channel. The sonar is operable in two modes, the channel measurement mode and the normal active mode. In the channel measurement mode, probe signals are transmitted to test the channel response. From the sonar receive signals resulting from the transmitted probe signals, the channel scattering function is estimated. The transmit waveform for the sonar active mode is then designed to provide a waveform whose ambiguity function overlaps minimally with the estimated channel scattering function.

Abstract: A cavity which is resonant at a laser pumping frequency is defined by a reflective surface (92) and a mirror (110). A Raman medium (106) is contained within the cavity, as is a laser (90). A Q-switch (94), when not spoiling the Q of the cavity, allows photon density to increase within the cavity. When the Raman threshold of the Raman medium is exceeded, the Raman medium absorbs and then radiates photons. The radiated photons are at longer wavelength than the laser photons, and also occur in very short (less than ten nanoseconds) pulses. The radiated photons are reflected by a mirror (101) and exit the cavity through one of the reflectors defining the cavity (mirror 110). The invention shifts the wavelength and shortens the pulse duration of pulses produced by the laser (90).

Abstract: A cellular array processor (10) for efficiently performing data dependent processing such as floating point arithmetic functions. One module (84) in the array processor (12) generates a signal applied to bus line (24) when all of the bits in a register (86) are zero. The signal on bus line (24) effects the shifting operation of a shift register (36) in a memory module (34) located on a different functional plane. Thus, the processing functions carried out in each elemental processor (26) can be made to depend on the value of data stored therein instead of being dictated solely by a simultaneous executed instruction from the control processor (14) as is the normal case.

Abstract: A one-piece gasket is used between millimeter waveguide sections to prevent energy leakage from the joint. The gasket consists of an electrically conductive elastomeric ring filled with metallic particles, a conformable metallic inner shield on the inner periphery of the ring, and a conformable metallic outer shield on the outer periphery of the ring. The gasket is conveniently prepared by casting the filled elastomer in place between the shields.

Abstract: A mercury compound such as mercury telluride or mercury cadmium telluride is deposited upon a substrate by chemical vapor deposition, with dissociation of the organic compounds accelerated by laser energy. The mercury-containing compound is preferably divinylmercury, which dissociates under intense light of 248 nanometers wavelength to deposit mercury in combination with the codeposited element. The laser-assisted chemical vapor deposition is accomplished at 100.degree. C. to 195.degree. C., preferably 165.degree. C., without the deposition of carbon contaminants.

Abstract: A laser transmitter utilizes optical far field combination of two independent lasers (80,90) and variation of RF exciting power (86) to one (80) to produce sufficient frequency modulation. Two bores (122,124) within the same dielectric body (120) are provided with two independent sets of electrodes (134,135, 138,139) and two independent RF power sources (150,152). The lasers are operated at different frequencies and the beams transmitted in parallel adjacent paths to provide a combined far field optical beam component at the beat frequency of the two lasers. Variation of the frequency of one of the lasers provides frequency modulation of the far field beat frequency, enabling reception and demodulation of the modulated beam without use of a local oscillator laser at the receiver. The transmitter may also be used in a laser radar.

Abstract: An improved target association method including the steps of: (a) generating electrical or optical signals representing target detections from an image sensor; (b) storing the signals from a first detection interval in a first memory as a first frame of data; (c) storing the signals from a second detection interval in a second memory as a second frame of data; (d) generating a matrix of cost functions having n rows corresponding to n targets from the first frame of data and m columns corresponding to m targets in the second frame of data, each cost function being a function of one of n targets in a first frame of data and one of m targets in a second frame of data; (e) ordering the rows of the matrix by: (i) computing for each row a value equal to the difference between the two smallest cost functions in the row; (ii) identifying and selecting as an initial starting row, the row with the largest difference value, and removing from consideration for the calculation of difference values for subsequent rows, the

Abstract: A field effect transistor FMCW radar transceiver for short-range target detection, employs a varactor-tuned, gallium arsenide field effect transistor, voltage-controlled oscillator in the dual role of the transmitter signal source and the local oscillator. The radar transceiver is capable of operating at low IF frequencies for short range, which can be less than 30 feet, target detection.

Abstract: An image of a target (11) is produced by illumination of the target (11) with overlapping fields (18, 20) of wave energy, such as coherent light, producing an interference pattern (22) moving across the target. At least one pair (12) of sources (14, 16) wave energy provide the moving interference pattern (22). The scattered illumination reflected from the target is detected by a non-imaging receiver (24); a two dimensional spatial frequency map is recorded (30, 62), based upon the amplitude, frequency and phase of the illumination received; and a two dimensional image of the target is formed (32, 72) by applying a Fourier transform to the two dimensional frequency map.

Abstract: A wavefront vector correlation processor provides rapid, weighted correlation of a given vector with other vectors in a given vector space. In one embodiment the processor includes an interconnected two-dimensional array of simple processing elements that is an electronic analogue of the X,Y plane. Each processing element is connected to neighboring processing elements and is capable of transmitting a pulse to its neighboring processing elements in response to an input pulse. An initial pulse initiated at a processing element having a first classification causes electronic ripples to spread out in chain/reaction among neighboring processing elements. When the electronic ripple reaches processing elements having a second classification, a controller circuit senses these events and measures the time between the initial pulse and the detected pulse. This measured time may then be used to provide correlation between the vector of the first classification and vectors having a second classification.

Abstract: A capacitive feedback transimpedance amplifier 10 comprises a differential amplifier constructed of GaAs transistor Q.sub.1 and Q.sub.2 and has an input coupled to the output of an infrared detector 12 and an output expressive of the detector signal integrated over a predetermined interval of time. The amplifier has a transistor Q.sub.0 coupled to the input for coupling the input periodically to a predetermined voltage potential and a transistor Q.sub.9 coupled to the output of the amplifier for simultaneously periodically coupling the output to a predetermined voltage reference, thereby initializing the amplifier at the beginning of an integration period. A load is coupled between an amplifier output terminal a source of amplifier power. The load includes a resistor having a first terminal coupled to the amplifier output terminal and a second terminal coupled to a first GaAs load transistor. The first load transistor is serially coupled to a second load transistor.

Abstract: The process comprises the testing of an electrical component during transit from a pickup position to its attachment position. The process may be accomplished by the use of a component test chuck (30) which has four pivoted arms (66, 68, 70, 72), each carrying a finger (90, 92, 94, 96). The fingers are sized and positioned for engaging on and retaining an electrical component. Two of the fingers have tips (102, 104) which are electrically conductive and are connected to a test unit (106) so that the component (93) can be tested in transit between the pickup point and the placement point.

Abstract: An optical element (10) is mounted and aligned with minimum strain and distortion within a support (12) to which at least three mounts (14) are attached and spaced 120.degree. about the periphery of the optical element. Each mount comprises a spherical disc (16) spherically contacting a spherical surface (30) on a seat (20) which is linearly moveable within a housing (18). Each disc abuts and supports the optical element. Any loading exerted on the support causes the discs to rotate with respect to the seats and the seats to reciprocate with respect to the annular disc-retaining housings to prevent such loadings from being transmitted to the optical element, thereby enabling the optical element to maintain a chosen, strain-free orientation with pressure on the spherical disc being evenly distributed.

Abstract: A wideband, true time delay antenna beamforming network 10 for millimeter wave phased array antennas is disclosed herein. The beamforming network 10 of the present invention includes a laser 30 for generating a beam B of electromagnetic energy. The beamforming network 10 further includes an electro-optic modulator 40 for modulating the beam B in response to an input signal S modulated about a first frequency f.sub.o. A first antenna array 80 generates a first electromagnetic field pattern P by radiating the modulated beam B' in a first direction. The present invention further includes a constrained lens 90 for receiving the first field pattern P and for emitting an antenna driver feed beam F in a second direction in response thereto. An antenna array driver 115 electro-magnetically coupled to the constrained lens 90 by the feed beam F provides a set of signals modulated about the first frequency f.sub.o to drive an antenna array 20.

Abstract: Apparatus comprising an indium bump that may be etched in a low concentration of hydrochloric acid (typically 1%) to remove oxide buildup, and a pad generally comprising a three layer arrangement of gold over nickel over titanium. The indium bump and the gold pad are pressed together for a short period of time, typically on the order of ten seconds, and then the pressed components are allowed to alloy weld over an extended period of time. Alternatively, the bump and pad may be heated at approximately 100 degrees Celsius for a period of about one hour to accelerate the alloy process. The heating diffuses the gold from the pad into the indium bump, thus forming a true alloy weld between the two that has incredibly strong bonding strength. Such bonding materials and methods are useful in bonding integrated circuit components, and the like.

Abstract: An inexpensive broadband dynamic IR target with a fast response time, good spatial resolution, and adequate dynamic range is disclosed. The IR target is made by coating a thin photo-conductive film on a transparent insulator. The emissivity of the film-substrate block is changed by irradiating the block with a visible image of the desired IR image. The image temperature varies from the block temperature T by an amount related to the photo-conductivity produced change in the emissivity.

Abstract: Multiple pupils (16, 18) are formed in a projection display by employment of a field lens (14) which has at least first and second interleaved Fresnel lens segments. The first set of segments has the equivalent surface of a first lens (34) and the second set of interleaved segments has the equivalent curvature of a second lens (36), with the segments being shaped to produce two exit pupils. More exit pupils, up to four without loss of resolution, can be provided by the interleaving of further lens shapes. A separate lens face (30) controls the other dimension of the exit pupils. The additional lens face may be a Fresnel lens on the opposite side of the same lens element.

Abstract: A chirped backscatter filter 10 compares a received signal (RSIG) to a reference signal related to a transmitted signal (TSIG) and removes from RSIG the frequency component which is equal to TSIG in frequency. This removed frequency component corresponds to the frequency of the transmitter backscatter radiation. The filter of the invention adds a frequency offset (f.sub.n) to both RSIG and TSIG in mixers 12 and 14 before substracting one from the other in mixer 22. Thus, equal frequency components in both RSIG and TSIG, such as the backscatter radiation frequency component of RSIG, will equal f.sub.n. The frequencies resulting from this subtraction are thereafter passed through a notch filter 24 which is centered on f.sub.n and which passes all frequency components except f.sub.n. The output of the notch filter thus no longer has a frequency component associated with the backscatter frequency component.