Abstract: A Time Division Duplex (TDD), Code Division Multiple Access (CDMA) communication system includes a plurality of Customer Premises Equipment (CPE) and an Access Point (AP) that communicate through RF links. A CPE contains a receiver baseband subsystem and a transmitter baseband subsystem, and further contains receiver circuitry operable during a receive period for receiving an RF carrier from the AP and for deriving a receiver tracking signal that is indicative of a frequency and phase shift between the received RF carrier and a reference signal. The receiver circuitry further includes a frequency to phase accumulator (FPA) and a digital phase shifter (DPS) for correcting the frequency and phase of a receiver baseband signal by an amount and in a direction indicated by the receiver tracking signal.

Abstract: A trace sampling detection system includes a gathering device configured to gather particles through a handle-bar, a gate and an air-stream gatherer. The handle-bar includes collection holes positioned to be adjacent to a user's hand when the user grips the handle-bar, and is configured to dislodge and capture particles from the user's hand when the user grips and moves the handle-bar. The gate includes a series of collection holes, is positioned to be adjacent to the user's clothing when the user traverses the gate, and is configured to dislodge and capture particles from the user's clothing in response to pressure applied from the user. The air-stream gatherer includes an outward vent and an in-drawing vent, and is positioned to enable objects, such as the user's feet, to be placed between the outward and in-drawing vents. The air stream is configured to dislodge and capture particles from objects, such as the user's feet, that block the air-stream between the vents.

Abstract: Screening of items for the presence of contaminants, such as explosives residue, is accomplished by subjecting an item loaded into a pressure chamber to a pressure substantially in excess of atmospheric pressure conditions and rapidly decompressing the item to the ambient atmospheric pressure. The rapid decompression serves to scavenge vapors and particles from the exterior and interior of the item and any objects it contains. A sample of the vapors and particles removed from the item by the rapid decompression is sampled and is tested to determine whether a predetermined contaminant is present in the sample. Depending on the types of contaminants for which the sample is tested, it is possible to detect whether explosives, biological or chemical agents, and/or narcotics residues are present on or in the item being screened.

Abstract: In one aspect, an x-ray scanning device is provided. The x-ray scanning device comprises a target adapted to convert electron-beam (e-beam) energy into x-ray energy, a detector array positioned to detect at least some x-rays emitted from the target, and a conveyer mechanism adapted to convey items to be inspected through an inspection region formed by the target and the detector array, wherein the target and the detector array are rotated out of alignment with each other such that x-rays emitted from the target impinge on diametrically positioned detectors of the detector array without passing through near-side detectors of the detector array.

Abstract: A system for fast data encryption/decryption is provided. The system includes a transmitter system having a transmitter direct digital synthesizer (DDS). The DDS includes at least three transmitter pseudo-noise (PN) component code generators PNx, PNy, PNz, where each transmitter PN component code generator is adapted to generate relatively prime transmitter PN component codes when compared with each of the other transmitter PN component code generators. The transmitter also includes a first processor coupled to the transmitter DDS, where the first processor is adapted to determine a time slot number (TSN) relative to at least two of the relatively prime transmitter PN component codes. Also included in the transmitter is an encryptor for encrypting clear data in accordance with the TSN. The system includes a receiver system having a second processor adapted to determine the TSN; and a decryptor coupled to the second processor.

Abstract: A radial power divider-combiner is disclosed. Such a radial divider-combiner may include a plurality of waveguides, each of which extends between a central monopole antenna and a respective peripheral monopole antenna. Such a waveguide may have a central portion with a height-to-width ratio of two, and a peripheral portion having an aspect ratio of one. To improve impedance-matching, a transformer portion may be disposed between the central portion and the peripheral portion. Such a transformer portion may have any number of sections, from one to infinity, with each section having a respective height between that of the central portion and that of the peripheral portion. In the extreme case, where the number of “sections” is infinite, the height of the transformer portion may vary linearly from that of the central portion and that of the peripheral portion.

Abstract: A method and system for determining Psuedo-Noise (PN) composite phase is provided. The method includes providing at least three relatively prime PN component codes and partially correlating a received PN composite encoded signal with one of the PN component codes. The method also includes partially correlating the received PN composite encoded signal with a second one of the PN component codes while maintaining phase alignment of the first partially phase aligned PN code through the use of normalized autonomous phase numbers (NAPNs). The received PN composite encoded signal is then phase aligned with a receiver PN composite code phase in steps of epoch lengths of the partially phase aligned PN component codes.

Abstract: A communications system employs the use of both synchronous CDMA and FDMA to provide a variable bandwidth waveform with multiple bonded transmitters and receivers that are agile in both frequency and PN code to permit a variable bandwidth and variable rate multiple access system. In a first aspect the teachings provide the use of both CDMA and FDMA together to enable an improved concentration efficiency by making a larger pool of bandwidth available to each user. In a second aspect these teachings enable channel bonding across both code space and frequency space, thus making the system capable of operating within a variable (not necessarily contiguous) bandwidth and at a finely variable rate.

Abstract: A rugged, miniature, waterproof and lightweight magnetic latching indicator with an auxiliary switch. The indicator includes a solenoid, an elongated plunger mounted in the solenoid, the plunger supporting a first permanent magnet with the magnet being surrounded by specially dimensioned non-magnetic spacers. The plunger and solenoid are packaged in a non-magnetic housing with a solenoid locator, a top cap and a bottom cap maintaining the indicator in a compact waterproof package. An indicator button is mounted to the plunger and a reed switch biasing spring and second permanent magnet are located between the bottom cap and the solenoid. The plunger moves from a retracted latching position to an extended position. In the retracted position, the indicator button is retracted and not readily visible and the second permanent magnet maintains the reed switch in a closed position.

Abstract: A frequency-stepped radar may be used to detect buried landmines by sequentially inducing vibrations of different frequencies in the landmine. A sensor detects signals associated with the vibrations, and a processor processes the signals to detect the landmine.

Abstract: A system for transporting data comprising a first domain comprising a first plurality of filters in a first communication channel, the first communications channel including a common portion, the first plurality of filters employing a first plurality of filtering criteria; a second domain comprising a second plurality of filters in a second communications channel, the second communications channel including the common portion, the second plurality of filters employing a second plurality of filtering criteria; a plurality of managers each coupled to one of the first plurality of filters and the second plurality of filters, each of the plurality of managers comprising means for configuring the one of the first plurality of filters and the second plurality of filters; and at least one control terminal coupled to the plurality of managers for controlling said plurality of managers.

Abstract: A concealed object detection system for detecting objects concealed on a person includes radar transceivers that are each configured and positioned to direct a radar signal at a person and to detect a portion of the radar signal reflected by the person. A processor connected to the radar transceivers processes the portions of the radar signals detected by the radar transceivers to determine whether the person is carrying a concealed object. The system may produce a real-time alert, such as an audible alert, when a concealed object is detected.

Abstract: A radiation (e.g., X-ray) source and collimator assembly with no moving parts provides a swept-line scan of radiation suitable for imaging or analyzing radiation scattered from an object. Scatter radiation is sensed by (e.g., scintillation devices) to produce a signal which is then able to be processed to produce an image, or to be analyzed.

Abstract: This invention generates pseudo-noise (PN) codes that map a transmitted data rate into the PN code structure. This invention further then acquires the PN code to automatically discover the transmitted data rate. This invention is operable with communication systems that utilize GPS time synchronization of the transmitted and received PN codes, as well as with communication systems where GPS time synchronization is not available. A method and a system are disclosed to transmit a modulated signal from a transmitter to a receiver, where the modulated signal has a data rate. The method includes selecting, to represent the data rate, at least one PN component code from a set of PN component codes. The PN component code is a constituent code of a composite PN code comprised of a plurality of PN component codes. The selected PN component code is one that phase aligns with a PN composite encoded signal.

Abstract: A method and system for compensating digital data demodulation phase uncertainty is provided. The method includes the steps of identifying a phase reference quadrant, the phase reference quadrant having a phase reference axis and four quadrants, I, II, III, and IV; receiving known digital data; and forming a phase vector from the known digital data, determining which quadrant the phase vector is located in and rotating the phase vector to the phase reference quadrant if it is determined that the phase vector is not located in the phase reference quadrant. The last step generates a phase error signal proportional to the resulting angle by rotating the phase vector ?45° and measuring the resulting angle between the phase vector and the phase reference axis.

Abstract: A high-power microwave generator employing a plurality of inexpensive commercial magnetron tubes cross-coupled by means of a secondary coupling path between each magnetron output pair, whereby a portion of the output energy from a first magnetron tube is injected into a second magnetron tube and a portion of the output energy from the second magnetron tube is similarly injected into the first magnetron tube. The resulting cross-injection of microwave energies brings the respective magnetron tube pair into a phase-lock sufficiently stable to permit coherent combination of their outputs for many high-power microwave applications, such as directed energy weapon systems. The magnetron phase-locking system requires no external components other than the secondary coupling paths of this invention.

Abstract: A novel MODEM and method of operating a MODEM usable in spread spectrum communication utilizing multiple waveforms in orthogonal spread signals imbeds a tracking signal in one of the spread signals for efficient tracking by a receiver so that both spread signals can have wideband characteristics. Therefore, one spread signal contains a tracking channel and a wideband channel, allowing for higher order modulation in the wideband channel for transmitting information, while still providing good tracking features. The second spread signal is an orthogonal wideband channel serving as the main high data rate conduit. In the preferred embodiment, the first portion of the waveform (in the first spread signal) is modulated using Bi-Bi-Phase Shift Keying (Bi-BPSK), while the second portion of the waveform (in the second spread signal) is modulated using Multiple Phase Shift Keying (MPSK). The two waveform portions are Time Division Multiplexed (TDM) at the chipping rate.

Abstract: A data link system comprising a shelter housing sensitive radio frequency equipment and an antenna located apart from the shelter. A single fiber, bi-directional fiber optic link couples the antenna to the shelter. Both RF signals and data signals are sent across the data link.

Abstract: An angular analysis system that can be controlled to receive radiation at a defined angle from a defined focus region. The angular analysis system is used for level 2 inspection in an explosive detection system. Level 2 inspection is provided by a three-dimensional inspection system that identifies suspicious regions of items under inspection. The angular analysis system is focused to gather radiation scattered at defined angles from the suspicious regions. Focusing may be achieved in multiple dimensions by movement of source and detector assemblies in a plane parallel to a plane holding the item under inspection. Focusing is achieved by independent motion of the source and detector assemblies. This focusing arrangement provides a compact device, providing simple, low cost and accurate operation.

Abstract: An angular analysis system that can be controlled to receive radiation at a defined angle from a defined focus region. The angular analysis system is used for level 2 inspection in an explosive detection system. Level 2 inspection is provided by a three-dimensional inspection system that identifies suspicious regions of items under inspection. The angular analysis system is focused to gather radiation scattered at defined angles from the suspicious regions. Focusing may be achieved in multiple dimensions by movement of source and detector assemblies in a plane parallel to a plane holding the item under inspection. Focusing is achieved by independent motion of the source and detector assemblies. This focusing arrangement provides a compact device, providing simple, low cost and accurate operation.