Abstract: A rugged patch antenna is described that is low profile and capable of resisting environmental and physical impact. The electrical properties of the antenna do not depend on the nature of the underlying surface. The standing wave ratio, return loss and impedance of the antenna are of sufficient quality to support efficient one and two way communications. The antenna can be mounted on vehicles, aircraft, spacecraft, manhole covers, utility covers, equipment cabinets, personnel and animals.

Abstract: A low cost capacitive fingerprint sensor which can be fabricated on various substrates, such as large glass or plastic substrates. The sensor is made by depositing and patterning alternate layers of conductive and insulation materials. A pixel of the sensor is comprised of a pick up pad and a plurality of voltage electrodes symmetrically placed around the pick up pad. The symmetry is such that only when a finger surface ridge is present, the pick up pad registers a signal.

Abstract: A two dimensional array of electrods for sensing the presence or absence of the ridges in a fingerprint through capacitive measurements. Exciting signals are supplied from outside the array which allows the array to be fabricated from metal and insulator layers on non-semiconductor substrates such as glass or plastic using normal deposition and patterning techniques. A top protective layer consisting of hard, rigid material may be provided. The required electronic circuits are preferably located around the periphery of the array.

Abstract: A low cost capacitive fingerprint sensor which can be fabricated on various substrates, such as large glass or plastic substrates. The sensor is made by depositing and patterning alternate layers of conductive and insulation materials. A pixel of the sensor is comprised of a pick up pad and a plurality of voltage electrodes symmetrically placed around the pick up pad. The symmetry is such that only when a finger surface ridge is present, the pick up pad registers a signal.

Abstract: A two dimensional array of electrodes for sensing the presence or absence of the ridges in a fingerprint through capacitive measurements. Exciting signals are supplied from outside the array which allows the array to be fabricated from metal and insulator layers on non-semiconductor substrates such as glass or plastic using normal deposition and patterning techniques. A top protective layer consisting of hard, rigid material may be provided. The required electronic circuits are preferably located around the periphery of the array.

Abstract: An image conversion device (14) comprising a detector (38) for detecting an infrared image and an image converter (40) for converting the infrared image to a visible image. The detector (38) and the image converter (40) are disposed on a single substrate. The detector (38) includes an array of multiple quantum well detectors (38) formed of GaAs or GaAlAs. The image converter (40) includes an array of light emitting diodes formed of GaAsP deposited on the array of multiple quantum well detectors (38). A photoemissive surface (28) is formed on the array of light emitting diodes (40) and a phosphor screen (30) displays the visible image.

Abstract: An analog signal processor for use with an array of uncooled detectors. Each detector has an amplifier associated therewith and each amplifier provides gain. A first circuit (212, 294, 300, 220) is included for compensating for a DC offset of each detector/amplifier pair of the array. A second circuit (250, 294, 300) corrects for variations in the sensitivity of each detector/amplifier pair. As a result, the outputs each of the detector/amplifier pairs in response to a common input signal are equalized. In a specific implementation, additional circuits are included providing global automatic DC level control across the array (270, 280, 294, 300), global automatic gain control across the array (250, 262, 294, 300) and frame-to-frame offset adjustment (212, 230).

Abstract: A digital signal processing system (100) removes DC bias in the output of a pyroelectric detector and similar types of detectors by adding together a first output signal which is inverted and a second output signal which is not inverted. The system (100) also removes offsets in the detector signal introduced by electronic circuits (readouts, amplifiers, drivers, etc.) between the detector and the system (100).

Abstract: An automatic gain and level control output circuit. The inventive circuit (10) includes a first component (12) for multiplying an input signal by a first reference signal to provide a gain adjusted signal. The input signal is level shifted by a second reference signal by a second component (16) to provide a level adjusted signal. The gain and level adjusted signals are compared to third and fourth reference signals by third and fourth components (26 and 28), respectively. The outputs of the third and fourth components (26 and 28) are combined to provide a first signal. Either the output of the third component (26) or the fourth component (28) is selected to provide a second signal having a first or a second level respectively. The first signal is integrated to provide the first reference signal and the fourth signal is integrated to provide the second reference signal.

Abstract: A high resolution gain response correction circuit. The inventive circuit (10) is adapted for use with a first circuit for providing a first analog input signal and includes a second circuit (R.sub.p, R.sub.ref) for providing a second input signal in response to the first input signal. A third circuit (12) is included for providing an analog output signal in response to the first and second input signals. In a particular implementation, the third circuit is a digital-to-analog converter (12). The digital-to-analog converter (12) is adapted to adjust the output signal level in response to an individual pixel correction reference signal. A digital potentiometer (R.sub.p) allows for the first input signal to be scaled and used to adjust the level of the second input signal. By adjusting the setting of the potentiometer, the dynamic range of the output to the digital-to-analog converter may be adjusted.

Abstract: An automatic gain and level control method and circuit. In general, the inventive method includes the steps of detecting the DC level of a signal and providing a first signal in response thereto and detecting the AC amplitude or gain of the signal and providing a second signal in response thereto. A DC level error signal is generated in response to the first signal. An AC amplitude error signal is generated in response to the second signal. The DC level of the signal is corrected in response to the DC level error signal. The AC amplitude of the signal is corrected in response to the AC amplitude error signal.

Abstract: An electron beam deflection circuit useful in cathode ray tube displays which employ television scanning principles. The deflection circuit is characterized by transformer coupling between a source of horizontal drive signal and a switching transistor for the horizontal deflection coil. Energy stored in the transformer during the scan and retrace time is utilized during the scanning time to provide base current to the switching transistor. In addition, the transformer has a second primary winding connected in the emitter circuit of the switching transistor in a manner to allow positive feedback. The positive feedback enhances and sustains the base current during scanning time and controls its magnitude. The circuit is advantageous in that it eliminates the need for precise waveshaping circuits at the input to the switching transistor and lowers the power requirements for the circuits which precede the switching transistor.