Abstract: A multi-tone CW radar (14) is used to project signals from an antenna (22) and to receive returns with the same antenna. The phase differences between the outgoing signals and the returns are analyzed to determine the existence of motion and the range to a moving object (10). A model is made which has range as its major parameter. A waveform associated with the phase difference between outgoing signals and returns for one of the tones is compared to templates produced by the model to determine which has a range that most closely matches. By varying the range parameters, when a match is detected the range to the object can be obtained even if its motion is pseudorandom. If the range is measured with multiple units it is possible to measure the location of the object. This can be done assuming a grid and algorithmically combining the ranges from the units.

Abstract: A CW radar (10) is used to detect motion of objects (22) behind a wall (20) by projecting a radar beam through the wall and by measuring the returns from the objects behind the wall, with a change in the phase difference between the transmitted and received CW signals providing an indication of motion behind the wall and thus the presence of an individual.

Abstract: A radio geolocation system is described in which a plurality of moving platforms such as aircraft concurrently receive a signal from a remote transmitter and the geolocation of the transmitter is determined. At each platform every thirty seconds a plurality of samples of the received signal are taken over a one second period. The samples are digitized and a time and GPS location stamp are added to each sample. The digitized samples with time and location stamps from all platforms are transmitted to a central location and stored in covariance matrices, one matrix per one second sample period. The signal samples in each matrix are processed utilizing a unique algorithm to generate a data set which defines a correlation surface. The data from a plurality of data sets are summed together on a point by point basis and normalized to yield a summation data set which defines a summation correlation surface.

Abstract: A GPS antenna with anti-jam capabilities utilizes eight resonant loop radiator elements in a resonant exciter configuration to make available a primary and up to seven auxiliary antenna patterns usable with multi-pattern adaptive processing for anti-jam operation. Antennas as described enable desired radiation characteristics to be provided in a configuration of small size suitable for replacement of existing GPS aircraft antennas which lack anti-jam capabilities, in order to enable reliable GPS reception during airborne operations in the presence of interference or jamming. With enablement of multi-pattern adaptive processing, reduced-gain pattern notches or nulls may be employed to track and reduce the effect of incident signals which would otherwise jam or interfere with reception of GPS signals.

Abstract: An etched grooved GaN-based permeable-base transistor structure is disclosed, along with a method for fabrication of same.

Abstract: A wideband meander line loaded antenna is configured to be flush mounted to a conductive surface serving as a ground plane by embedding the meander line components within a conductive cavity surrounded at its top edge by the ground plane. The antenna thus looks out of a cavity recessed in the surface. By permitting flush mounting the meander line antenna, not only can the antenna dimensions be minimized due to the use of the meander line loaded antenna configuration, but in aircraft applications no part of the antenna exists above the skin of the aircraft, thereby to minimize turbulent flow. Also disclosed is a method and apparatus in which a lossy dielectric is placed across the feed points of a loop type meander line loaded antenna to markedly decrease the VSWR to below 3:1, thus to increase the bandwidth of a relatively wideband 3:1 meander line loaded antenna to 6:1.

Abstract: Apparatus and a method utilizing correlation interferometer direction finding for determining the azimuth and elevation to an aircraft at long range and flying at low altitudes above water with a transmitting radar while resolving multipath signals. The signals from the radar are received both directly and reflected from the surface of the water using horizontally polarized and vertically polarized antenna arrays, are digitized and are stored in separate covariant matrices. Eigenvalues for the eigenvectors of the matrices processed on signal samples recorded on horizontally polarized X arrays are compared to the eigenvalues for the eigenvectors of the covariance matrices processed on signal samples recorded on vertically polarized X arrays. Incident field polarization is associated with the antenna array measurements that yield the strongest eigenvalue. The eigenvector and eigenvalues for the strongest signal are selected and used for subsequent signal processing.

Abstract: In a method and apparatus for controlling the deployment of a towline connecting a mooring craft to an ejected object comprising the steps of monitoring velocity to determine when a point for optimum braking has been achieved and then engaging a brake system to retard deployment of the towline, a DC motor augments and controls the brake system. The DC motor further controls the retrieval of the object. A cutter mechanism uses a first blade to grip the towing cable to maintain tension thereon as a second blade cuts the cable. A spring biased boom in combination with spring biased fins on the ejected object rapidly deploys the object from its storage housing. A locking mechanism secures the deployment mechanism in a stable locked position upon the object reaching its fully extended position.

Abstract: Interference cancellation techniques for use in a wireless multicarrier communications system where signals from multiple wireless networks might be present and interfering with the detection and demodulation processes are disclosed. Interference cancellation is applied to the interfering network before removing same-system interference. By removing the contribution of all interfering systems' from a receiver's aggregate signal, the receiver is capable of detection and demodulation. Performance can be further improved by including an additional level of interference cancellation within the system of interest to separate the individual user of interest.

Abstract: A direction finding system is used in which a number of adjacent bands are sequentially measured in fast rotation, with the results from each of the bands being FFT processed to provide amplitude and phase information on all of the signals existing within the band. Upon ascertaining that one wishes to do a direction finding process, one merely accesses the information in the delay memory so that direction finding resources are only allocated to signals of interest and such that one does not have to re-do an FFT upon finding a signal of interest.

Abstract: An active armor system which includes an outer and an inner armor layer with a medial space between these inner and outer armor layers layer. One or more relatively small shaped charges are positioned on the inner armor layer in the medial space. If the outer armor layer is struck by a projectile having a shaped charge, one or more of the small shaped charges positioned in the medial space near where the projectile has struck the outer armor layer are detonated. The small shaped charges in the medial space are positioned so that when they are detonated, their jets will tend to intersect with or be oppositely directed to the jet from the shaped charge on the projectile so as to disrupt the jet from the projectile and prevent the penetration of the inner armor layer. The small shaped charges in the medial space may be detonated by an electrical current produced when a piezoelectric material, an electrostrictive material, or a magnetostrictive material in the outer armor layer is struck by the projectile.

Abstract: A multi-function core base cell includes a set of functional microcircuits. These microcircuits are used to design a Library of Logic Function Macros. The functional macros consisting of one or more microcircuits have a fixed and complete physical layout similar to a conventional standard cell library macro set. In addition to a core functional macro set, primary input/output buffers and commonly used single and dual port memory blocks are also defined in the library. The library includes all the ASIC synthesis, simulation, and physical design rules.

Abstract: Ground based GPS antennas for differential applications may be subject to intentional or other interference signals incident at low elevation angles. Described GPS antenna systems are usable to provide an antenna pattern having a vertically-steerable null. An array of vertically spaced radiator units having omnidirectional azimuth characteristics provides a primary reception pattern. Vertically intermixed radiator units employed on a separate or shared basis provide an auxiliary reception pattern. By subtractively combining the auxiliary pattern with the primary pattern and adjusting the relative signal level of the auxiliary pattern a vertically-steerable pattern null is provided. The antenna system may include an adaptive control system responsive to an antenna output signal to derive a steering signal to adjust the relative signal level of the auxiliary pattern to steer the vertically-steerable null to provide interference suppression. Antenna systems and methods are described.

Abstract: An apparatus for reducing offset voltage drifts in a charge amplifier circuit is disclosed. The apparatus includes a charge amplifier circuit and a bias current compensation circuit. The bias current compensation circuit supplies bias current to lower any offset voltage drift at the output of the charge amplifier.

Abstract: An etched grooved GaN-based permeable-base transistor structure is disclosed, along with a method for fabrication of same.

Abstract: A bias generation circuit for biasing a differential amplifier is disclosed. The bias generation circuit is coupled to the differential amplifier. After determining a common-mode voltage of a pair of differential outputs from the differential amplifier, the bias generation circuit generates a bias voltage, which is proportional to the determined common-mode voltage, to the differential amplifier such that the common-mode input voltage range of the differential amplifier is extended to as far as the rail-to-rail voltage.

Abstract: Channel impulse response estimation employs a training sequence to enable correction for multipath and other disturbances affecting a signal during transmission via a digital wireless communication channel. High-speed packet transmission rates, with a training sequence for each packet, are made possible by training sequence construction enabling fast algorithm processing of received signals for impulse response estimation. Upon reception, a Toeplitz-type mathematical representation is constructed based on transmitted and received versions of a training sequence. The Toeplitz-type representation may then be processed by application of fast algorithms, such as Levinson-type algorithms, to determine coefficients representative of the communication channel impulse response. These coefficients, applied to an adaptive equalizer type of filter, enable correction for signal disturbances incurred in transmission. Channel impulse response estimation methods and systems are described.

Abstract: A precision targeting system for a firearm has an image capturing scope, a processor, and an actuator. In one embodiment, a user indicates when he wants to lock onto the target, and then readjust his aim after receiving feedback from the system. In another embodiment, the system automatically locks onto the target. After lock on, the system compares successive images, and determines if the target has moved in the firearm sight. If movement has occurred, the system calculates the degree of the movement, and sends appropriate signals to an actuator which corrects the aim of the firearm. The system thereby converts reasonably good aim into precision aim.

Abstract: What is provided is the use of an array of E-field sensors to detect the closest approach of incoming projectiles and to determine through time difference of arrival the bearing of the incoming projectile, thus to identify the bearing of the source of the projectile. dE/dT processing of the individual outputs of the E-field sensors indicates by the zero crossing the peak of the E-field disturbance and thus the instance of time of the closest approach of the projectiles to a sensor.

Abstract: E-field sensors are used to establish a protection zone around a vehicle so as to detect the presence of objects within the protection zone, be they other vehicles or individuals. In one embodiment the direction to the intruding object is established by virtue of the use of pairs of E-field sensors. In a further embodiment the range of the E-field sensors determines the limited protection zone around the vehicle. Because of the limited protection zone, false alarms are greatly reduced.