Abstract: A system and method (32) for measuring line-of-sight angular rates for all-weather precision guidance of distributed projectiles (16) and a guidance system (10) based thereon. In accordance with the novel method (32) for measuring line-of-sight angular rates, first the range rates of the target (14) relative to at least two projectiles (16) is determined, as well as the position and velocity of each projectile (16). Then, the line-of-sight angular rate of the target (14) relative to at least one projectile (16) is computed from the range rates, positions, and velocities. In the illustrative embodiment, the range rate of the target (14) relative to a projectile (16) is determined based on a monostatic target Doppler measurement, a monostatic projectile Doppler measurement, a bistatic Doppler measurement of the target (14) by the projectile (16), and the carrier frequency of a data link (26) between the projectile and the shipboard system.

Abstract: A method for exciting an antenna with a waveform having a burst width and pulse width scaled proportionately with a selected range scale and a temporal filter to address any ambiguities in range resulting from the transmission of a signal in accordance with the novel waveform. The inventive filtering method includes the step of scanning a beam including a plurality of pulses of electromagnetic energy. The step of scanning the beam includes the step of outputting a beam excited by a waveform having a burst width and pulse width scaled proportionately with a selected range scale. Reflections of these pulses are received as return signals. The returns are processed to extract range in range rate measurements. The range and range rate measurements are compressed to form a plurality of range bins. The pulses are selectively weighted to reduce sidelobes resulting from a subsequent Fast Fourier transform (FFT) operation.

Abstract: A voltage variable composite structure comprising: a first layer of metal; a second layer of low-loss dielectric material impregnated with an array of first metal vias; a third layer of a voltage variable dielectric material; a fourth layer of a patterned thin metallic film; a fifth layer of low-loss dielectric material impregnated with an array of second metal vias; and a sixth layer of metal.

Abstract: An imaging system and method. The invention provides an intra-pulse repetition interval (PRI) agile beam technique for enhanced resolution that can be used at aspect angles near the velocity vector of a host vehicle. It is particularly useful at small scan angles where beam sharpening array times become large. At these scan angles, the bandwidth of the clutter is narrower than at higher scan angles and allows large PRIs without degradation from Doppler ambiguities. In accordance with the present teachings, sequential illumination is performed within a PRI to multiple beam locations using an agile beam. The interleaving of beams reduces map formation times compared to conventional techniques using sequential arrays. The inventive system is adapted for use with an electronically scanned (e.g., synthetic aperture array radar) antenna.

Abstract: A space deployable antenna that includes an inflatable envelope, a cylindrical reflector formed on a wall of the envelope, a catenary support frame for maintaining the cylindrical shape of the cylindrical reflector, and a feed array support structure connected to the catenary support frame.

Abstract: A multifunctional laser (10) which, in a first operational mode, outputs a mode-locked beam for vibration sensing applications and, in a second operational mode, outputs a Q switched illumination beam for imaging applications. The inventive laser (10) includes a resonant cavity (110, 120, 190); a gain medium (100) disposed with the cavity; a first arrangement (150) in communication with the medium for causing a Q-switched signal to be transmitted from the cavity; a second arrangement (180) in communication with the medium for causing a mode-locked signal to be transmitted from the cavity; and a mechanism (130, 140) for switching between the first arrangement and the second arrangement.

Abstract: A system for locating the position of an emitter emitting a signal having time domain features is described. At least two platforms are used. Both have a receiver for detecting the emitter signal, an FFT channelizer to act as a bandpass filter for extracting the time domain features from the emitter signal, and a thresholder for thresholding the time domain signal. An FFT transform and a correlator using templates further extract frequency domain markers identifying the emitter. The frequency domain markers identifying the emitter are transmitted between platforms using a wireless link increasing the probability of detection of the emitter at all platforms.

Abstract: A high gain optical amplifier and method. Generally, the inventive amplifier includes a first crystal having an axis and a first index of refraction and a second crystal bonded to the first crystal about the axis and having a second index of refraction. The first index is higher than the second index such that light through the first crystal is totally internally reflected. In the illustrative embodiment, the first crystal is Yb:YAG with an index of approximately 1.82, the second crystal is Sapphire with an index of approximately 1.78, and the axis is the propagation axis. The invention is, in its preferred embodiment, a light guide fabricated out of crystalline materials, diffusion bonded together. If the core of the light guide is doped with laser ions, high gain amplifiers made be designed and operable over a large étendue.

Abstract: An efficient system (10) for measuring target characteristics via a torsion mode beam of electromagnetic energy. The system (10) includes a first mechanism (34, 38, 40, 42, 16) for transmitting the torsion mode beam toward a target (12). A second mechanism (16, 18, 20) receives the resulting target return beam and provides a first signal in response thereto. A third mechanism (26, 28) employs the first signal to determine rotational characteristics of the target (12). In a specific embodiment, the system (10) further includes a fourth mechanism (20, 26) that reduces or eliminates noise in the return beam based on common mode noise rejection. A fifth mechanism (32) identifies the type of the target based on the target rotational characteristics via comparison to predetermined target rotational signatures (36). An additional mechanism (24, 40, 42) selectively switches the mode of the beam between a first mode and a second mode.

Abstract: A novel and efficient system and method for providing an output beam of collimated energy in the 8-12 micron range. The solid state system includes a pump laser (210) for providing an input beam and an OPO (250) using an x-cut potassium titanyl arsenate crystal for shifting the input beam from the first wavelength to a second wavelength. A second optical parametric oscillator (271) is included for shifting the beam from a second wavelength to a third wavelength. The second optical parametric oscillator (271) uses a cadmium selenide crystal. A tuning mechanism with an associated controller is provided to tune the oscillator as needed for a particular application.

Abstract: A system and method for automatically generating a return beam in the direction of a received beam. The inventive system (10) includes a phased array antenna (12) for receiving a radio frequency signal having a first wavefront from a first direction. In response to this signal, the invention (10) provides a second signal having a second wavefront. The second signal is a phase conjugate of the first signal and is transmitted in a reverse direction relative to the direction of the first signal. In the illustrative embodiment, the invention includes a plurality of phase conjugators each of which are disposed in a transmit/receive module and coupled to an associated radiating element. Each of the phase conjugators includes a mixer (60) having the input signal as a first input thereto. The input signal has a first frequency and a first phase.

Abstract: An ion mobility spectrometer includes a housing with a flow channel, an air pump to force air through the flow channel, a heater at an inlet end of the flow channel, and an ionization source that ionizes the air after it is heated. The heated, ionized air passes through an electric field produced by a field source and a plurality of sensor elements located within in the wall of the flow channel in the measurement region of the electric field. The sensor elements include a plurality of sensor electrodes in one wall of the flow channel. Ion currents to the sensor electrodes are measured by an integrated high-sensitivity readout circuit array, permitting the sensor electrodes to be quite small. The sensor electrodes may be arranged in one-dimensional or two-dimensional arrays.

Abstract: A current switch circuit including a current switch including a first transistor and a second transistor connected as a differential pair and receiving a differential logic signal at their bases, and logic signal controlling circuitry coupled to the first and second transistors for offsetting a transition starting point of to differential logic signal to offset a self-heating induced shift in a switching threshold of the current switch.

Abstract: A micro electromechanical system (MEMS) transfer switch for simultaneously connecting two radio frequency (RF) input transmission lines among two RF output transmission lines. The MEMS transfer switch includes a plurality of series MEMS switching units operatively arranged with the input and output transmission lines to selectively connect a first input to a first output and a second input to a second output, or the second input to the first output and the first input to the second output.

Abstract: In accordance with one aspect of the present invention, a preprocessor is provided for use in an adaptive antenna array. The purpose of the preprocessor is to modify the incoming signals received by each antenna of an antenna array in such a manner as to reduce the amount of computation necessary to compute the adaptive array weights. In an adaptive array, the weight computation process generally requires calculations using digital electronics, which tend to be computationally intensive when applied to wideband, high sample rate signals. The preprocessor of the present invention solves this problem by filtering the data in such a manner as to reduce the sample rate of the signal without losing the essential characteristics of the signal. The preprocessor includes an input terminal for receiving an electromagnetic signal from an antenna element of the adaptive antenna array, and a frequency smearer operatively coupled to the input terminal.

Abstract: A bistatic radar system and method. In the illustrative embodiment, a receiver is positioned in a horizontal plane. A transmitter is then positioned in Middle Earth Orbit at a position that is nearly vertical to the plane of the receiver. This configuration provides significant flexibility for the radar system. As such, the radar system may engage in flight patterns, in which the transmitter and receiver have velocity vectors in opposite directions (GMTI mode), the same direction (SAR mode) and variations in between (mixed mode). Lastly, a broad beam is generated from the transmitter and illuminates an area enabling several receivers to simultaneously observe the illuminated area.

Abstract: A system and method for forming a beam and creating nulls. The inventive method combines frequency domain suppression technology for narrow-band jammer rejection with orthogonal weighting using Eigen analysis for jammer nulling and signal beam-forming for an array antenna system. The inventive system is adapted for use with an adaptive array antenna having a plurality of radiating elements. The system includes a frequency domain suppressor connected to the array antenna and an orthogonal weighting subsystem connected to the frequency domain suppressor. In the illustrative implementation, signals received by each radiating elements are processed by an analog front-end and digitized. The frequency domain suppressor includes a Fast Fourier transformer (FFT) and a frequency domain suppressor for each element in the array. The frequency domain suppressor further includes a threshold evaluator which reads the signals output by the FFT's and provides threshold controls to the spectral suppressors.

Abstract: An antenna system includes an array of notch radiators, arranged in aligned rows on longitudinal axes to define a series of troughs between adjacent notch radiator rows within an aperture area, each notch radiator including a tip region. A plurality of surface/traveling wave suppressors fabricated of microwave energy absorbing material is disposed in the troughs, so that a longest suppressor dimension is transverse or nearly transverse to the array face and so that a suppressor surface is transverse or nearly transverse to the longitudinal axes.

Abstract: The invention is an optoelectronic (OE) crossbar switch (10) for both digital and analog signals, used either separately or combined, whose functions are reconfigurable and distributed. The invention allows multiple senders to be connected with multiple receivers simultaneously. The invention uses optical filters for wavelength division multiplexing and demultiplexing (WDM and WDD). A single fiber module input/output port carries multiple bi-directional signals that are optically filtered out in the module using WDM/WDD filters (12) at each sender/receiver and then selected after optical filtering using photodiode detectors (15) as detectors and switches. Laser transmitters (14), photodiode detectors (15), and smart electronics (18) are used to implement the crossbar switch functions.

Abstract: A portable gas purge and fill system. The inventive system (10) includes a portable housing having gas inlet and outlet couplings. An electronic pressure gauge (30) is disposed within the housing (11) for measuring the pressure of the fluid at the outlet (24) thereof. A self-check mechanism (32) is disposed within the housing (11) for verifying calibration and operation of the electronic pressure gauge (30). A pressure regulator (20) is disposed within the housing and connected between the inlet (12) and outlets (24) thereof. A second gauge (14) is included for measuring the pressure of the fluid contained in the source. First, second and third two-way valves (18, 22, and 28) are included. The first two-way valve (18) is mounted between the second gauge (14) and the pressure regulator (20). The second two-way valve (22) is located between the pressure regulator (20) and the outlet (24). The third two-way valve (28) is located between the pressure regulator (20) and the self-check mechanism (32).