摘要:
Nuclear quadrupole resonance measurement using two or more wire loop(s) within a space to define a portal, and driving the wire loop(s) with a baseband digital transmitter generating a chirped or stepped signal, to create a corresponding varying electromagnetic field within the portal. Coherent emissions reflected thereby are detected through a directional coupler feeding the transceiver. The detected coherent emissions are processed with a matched filter to determine presence of a target object within the portal.
摘要:
An antenna formed from one or more structures with sets of radiating elements oriented in four different, preferably orthogonal, directions. The radiating elements are further provided as multiple horizontal and vertical radiating section. The structure may be a six sided cube-like structure or a cylinder. A combining circuit provides omnidirectional, directional, and scanning/direction finding modes across a broad operating frequency range with multiple polarizations. The arrangement lends itself to implementation as a whip form factor well suited for vehicular applications.
摘要:
A transmission line array is used for explosive/contraband detection using nuclear quadrupole resonance in which the array is driven in-phase with synchrony frequency-swept signals. Each of the balanced transmission lines is fed with a low power swept frequency source and stimulated emissions are picked out with a directional coupler. Location is provided using a cross grid array or a phase detector is used for each balanced line, with phase determining the distance to the sensed substance.
摘要:
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.
摘要:
Nuclear quadrupole resonance substance detection at a distance is provided by crossed or overlapping high frequency beams in which the frequency of one of the beams is offset with respect to the frequency of the other beam by an amount equal to the resonant frequency of the non-linear material to be detected. The presence of energy at the offset frequency within the overlapping beams pumps any non-linear material within the overlapping beams to cause stimulated emission which is detected, in one embodiment, utilizing a network analyzer, along with correlation of the detected stimulated emission signature with a library of signatures for predetermined substances.
摘要:
A neuromorphic parallel image processing approach that has five (5) functional layers. The first performs a frequency domain transform on the image data generating multiple scales and feature based representations which are independent of orientation. The second layer is populated with feature based representations. The third layer, an object class recognizer layer, are fused using a neuromorphic parallel processor. Fusion of multimodal data can achieve high confidence, biometric recognition.
摘要:
A dual purpose antenna is provided with the UHF antenna in the form of a pair of copper tubes to provide an off center fed dipole, with a pair of quadrafiler helix L1 and L2 GPS antennas stacked on top of the UHF antenna, and with the top section of the UHF dipole providing a ground plain for the GPS antenna. The antennas are fed internally by two coaxial feeds, one feeding the UHF antenna, the other passing through the UHF antenna to feed the GPS antennas. In one embodiment, a tuning coil is provided at the base of the UHF antenna by the coiling of the two coaxial feeds around a non-conductive mandrel, with copper taping placed on top of the coiled coaxial sections to provide an LC circuit to lower the resonant frequency of the UHF antenna to 225 MHz.
摘要:
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.