Abstract: A system and method for detecting at least one material under test (MUT) is presented. A Nuclear Quadrupole Resonance (NQR) measurement system includes a waveform generator configured to generate a continuous wave (CW) input signal comprising one or more frequencies. An RF shielded chamber receives the at least one MUT that is carried by a person walking through the chamber. A probe within the chamber illuminates the MUT with the CW signal and simultaneously receives possible NQR emissions from the at least one MUT. A bridge circuit is utilized to cancel the strong excitation CW signal from the generator which would otherwise mask the weak NQR emissions from the MUT that are received and detected by the measurement system. A detector can then detect the MUT based, at least in part, on the resonance signal.

Abstract: For use with an armored vehicle, a wideband embedded armor antenna is provided. The antenna includes an armor layer mounted to the armored vehicle. A driven dipole is mounted between the armor layer and the vehicle, the dipole operating in the UHF band. A first parasitically driven dipole is mounted on the outside of the armor layer. A second parasitically driven dipole is mounted between the driven dipole and the vehicle. A feed for the driven dipole is provided which does not pierce the armor layer.

Abstract: An extremely thin embedded antenna for an armor-carrying vehicle utilizes a dipole driven element to the inside of the armor plate and a parasitically-driven dipole element on top of the armor plate, with the parasitic element providing appropriate forward gain and antenna matching characteristics such that there need be no aperturing of the armor plate in order to feed the antenna. In one embodiment, the bowtie antenna elements are elongated, extended or expanded by outboard antenna sections which are spaced from the distal ends of the corresponding bowties, with a meanderline choke bridging the gap between a bowtie element and its extended portion.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

Abstract: A wide band frequency domain canceller is used in cosite mitigation interference in which a signal tapped from a transmit antenna is coupled to a Chirp Fourier Transform to covert the signal into the frequency domain. The frequency domain signal is vector multiplied with a path transform function to add the path transfer function values to the sampled signal, after which the processed frequency domain signal is converted back into the time domain by an Inverse Chirp Fourier Transform, after which it is inverted and coupled into the receive path of a cosited receiver.

Abstract: Techniques are disclosed for optimizing power consumption in electronic devices that operate on battery-based or scavenged power. The power scavenged or otherwise supplied by such devices may therefore last longer, allowing longer performance on a given charge (whether sourced from scavenged power, battery power, or a combination thereof). An energy distribution circuit can be used in conjunction with a hysteretic switch, wherein the hysteretic switch can be used to switch an energy storage element in-circuit (so that it can provide charge to sub-circuitry or components) when the charge stored on that element exceeds a given charge threshold; otherwise, the hysteretic switch presents as a high resistance or open circuit when the charge stored on the energy storage element drops below a lower recharge threshold. The energy distribution circuit can be configured for adaptively providing different discharge rates for different loads.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

Abstract: A wide band frequency domain canceller is used in cosite mitigation interference in which a signal tapped from a transmit antenna is coupled to a Chirp Fourier Transform to covert the signal into the frequency domain. The frequency domain signal is vector multiplied with a path transform function to add the path transfer function values to the sampled signal, after which the processed frequency domain signal is converted back into the time domain by an Inverse Chirp Fourier Transform, after which it is inverted and coupled into the receive path of a cosited receiver.

Abstract: A coherent RFID tag design having no internal power source is disclosed. The design exhibits a longer detection range and less interference relative to conventional tag designs. The coherent RFID tag design operates in a locked or stabilized fashion, in that the frequency at which energy is parasitically coupled to the RFID tag (via its antenna) is the same as the frequency at which the RFID tag transmits information utilizing the same antenna. The RFID tag design allows a greater number of RFID tags to be deployed, without causing cross-tag interference issues and the like.

Abstract: Techniques are disclosed for optimizing power consumption in electronic devices that operate on battery-based or scavenged power. The power scavenged or otherwise supplied by such devices may therefore last longer, allowing longer performance on a given charge (whether sourced from scavenged power, battery power, or a combination thereof). An energy distribution circuit can be used in conjunction with a hysteretic switch, wherein the hysteretic switch can be used to switch an energy storage element in-circuit (so that it can provide charge to sub-circuitry or components) when the charge stored on that element exceeds a given charge threshold; otherwise, the hysteretic switch presents as a high resistance or open circuit when the charge stored on the energy storage element drops below a lower recharge threshold. The energy distribution circuit can be configured for adaptively providing different discharge rates for different loads.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

Abstract: A coherent RFID tag design having no internal power source is disclosed. The design exhibits a longer detection range and less interference relative to conventional tag designs. The coherent RFID tag design operates in a locked or stabilized fashion, in that the frequency at which energy is parasitically coupled to the RFID tag (via its antenna) is the same as the frequency at which the RFID tag transmits information utilizing the same antenna. The RFID tag design allows a greater number of RFID tags to be deployed, without causing cross-tag interference issues and the like.

Abstract: A multi-port junction is used in combination with an Inverse Fourier Transform to detect distance to fault in an RF transmission line or waveguide without the use of heterodyne down-conversion circuits. To provide an ultra-wide bandwidth frequency domain reflectometer the output ports of the multi-port junction are used to calculate distance to fault and return loss. The Inverse Fourier Transform algorithm is modified to take into account both phase shift per unit length of the transmission line and attenuation per unit of length in the transmission line, with the output of the modified Inverse Fourier Transform being applied to a module that subtracts out the effect of previous faults by solving for the distances ahead of time before knowing amplitudes and for solving for amplitude at each prior fault starting with the first fault. The output of this module is then used thresholded to remove the effects of noise, secondary reflections and inconsequential peaks.

Abstract: A high-frequency, high-power generator of the type in which energy is stored in the capacitance of a transmission line and then discharged into a load by the action of a spark discharge device. The load is connected between one end of a transmission line conductor and ground and the other end of the same conductor is grounded. The line is folded and both ends of the other transmission line conductor are connected to the spark discharge device. A charging circuit applies a voltage to the latter conductor and when it reaches the discharge potential of the spark discharge device, the latter discharges to connect both ends of that conductor to ground. This provides relatively well-defined positive and negative pulses to the load.