Abstract: A process for locating a transmitter in which the signal is received by first and second receivers and then processed by respective analog to digital converters and filtered to yield first and second digital signals. There is relative motion between at least one of the receivers and the transmitter. A compression process local to the first receiver compresses the first digital signal. The result of the compression process is transmitted to a cross-correlation unit which is local to the second receiver and coupled also to receive the second digital signal. Locally to the first receiver, correction factors for the solution to the cross-correlation function are determined and transmitted to a correction unit at the second receiver site which applies the correction factors to the solution of the cross-correlation function. The location of the transmitter is determined based on time difference of arrival and frequency difference of arrival results output from the correction unit.

Abstract: A method and system for generating an anti-aliased image of a three dimensional surface is described. A point of view of the display screen is specified by an azimuth angle and an elevation angle with respect to the three-dimensional surface. The surface is defined as a two-dimensional array of height values. The projection of a point of the surface to the display plane is performed by applying a rotation based on the azimuth and elevation angles, followed by a parallel projection to the display plane so that, the columns of the surface project to the columns of the display screen. The points of the surface are projected in pairs, starting with the nearest points within a column and proceeding to the farthest points of the column. The grey-level shading (or color) values are accumulated in a one-dimensional array of floating-point variables that store the intensities of the pixels of a column of the display screen.

Abstract: SOI (silicon-on-insulator) technology has been touted as a promising approach for fabricating advanced integrated circuits because of its advantage over bulk silicon circuits such as faster speed and improved radiation tolerance. One drawback to SOI is that parasitic bipolar induced latch-up/breakdown voltage levels severely limits the maximum supply voltage at which SOI circuits and devices can operate. When the parasitic device turns on, the SOI transistor cannot be switched off by changing the gate bias. What is described is a method whereby the operating voltage in which this effect occurs is significantly increased thus allowing circuit operation at reasonable power supply voltages. The method is to implant an electrically neutral in silicon impurity atom such as krypton, xenon or germanium into the device to form ion scattering centers. The size of the impurity atom must be much larger than the size of the silicon atom. The size difference generating a scattering center.

Abstract: A single event upset hardened bi-stable CMOS circuit has a pair of cross coupled invertors with an isolation resistor in the path coupling the drains of the transistors in each invertor. Each invertor includes a PFET and a NFET pair coupled source to drain. An isolation resistor couples together the drains of each PFET-NFET pair and two low impedance conductive paths provide a direct coupling between the drains of each transistor of one invertor to common gate node of the other invertor.

Abstract: In a system for detecting the position and trajectory of a target, Doppler measurements from a bistatic continuous wave radar system are used exclusively to provide information about the target. Radar signals are transmitted to the target by a plurality of transmitters and at least one receiver is provided to receive the signals from the target and make Doppler measurements. A nonlinear least squares estimator is used to estimate the initial target position and a Kalman filter is used to predict the target trajectory from the initial position assumed by the NLS estimator and from the Doppler measurements. The Kalman filter also generates a set of predicted Doppler measurements from the predicted trajectory. The nonlinear least squares estimator is used to compute a correction to the estimated initial position from partial differentials of the initial position and from the differences between the predicted and actual Doppler measurements.

Abstract: Linear and decision feedback equalizers which are communication receivers used in computer systems having an ISI receiver system and analysis paradigm to provide the ability of estimating the performance of these receivers under mismatched channel conditions. The mean square error (MSE) performance of linear and decision feedback equalizers in the presence of arbitrary channel mismatch is presented. A generic equalizer which has feed-forward and feedback taps which are optimized for a mean square error (MSE) criterion. The ability to rapidly predict MSE performance also leads to the real-time adaptation of the equalizer complexity to improve MSE performance, optimal truncation of channel impulse response based on an MSE criterion, and assessing the impact of assuming white noise in a colored noise environment. With the system and method there is a determination of the spectral characteristics of the communication channel during training and/or decoding.

Abstract: In 1-X proximity X-ray lithography involving an X-ray mask having a ring, a rectangular membrane formed in a mask element, and a design pattern defined on the membrane, mechanical devices are provided to produce torque in the ring and, thereby, stretch or shrink the membrane and the design pattern. The mechanical devices are arranged on axes intersecting one another and extending diagonally through the corners of the membrane, as well as on axes which bisect angles formed by the intersection of the corner axes.

Abstract: SEU immunity is provided in a cross-coupled CMOS latch circuit by inserting a pair of series connected invertors between the drain node of one CMOS invertor and the gate node of the other CMOS invertor and a pair of series connected invertors between the drain node of the other CMOS invertor and the gate node of the one CMOS invertor. The invertor pairs delay the propagation of a change in voltage induced by an energetic ion strike at the off drain of one invertor to the gates of the transistors making up the other cross coupled invertor. The invertor connected to the gates of the transistors affected by the ion strike help in restoring the circuit to its original state.

Abstract: Interactive graphical attitude maneuver planning computer system for planning satellite attitude maneuvers allows a user to immediately see where star trackers are pointing when the attitude and orbital position of a satellite are varied on the computer system. The computer system includes a graphics display on which the celestial sphere, centered at the satellite rather than the Earth, is projected. The horizontal axis of the display measures the Right Ascension angle, while the vertical axis measures the Declination angle. The display shows, in addition to stars, the region of the sky occluded by the Earth and interference regions around the moon, sun and planets, in which the star trackers should not point, and the fields of view of the star trackers. The attitude of the satellite is adjusted by means of graphical slider bars which vary the roll, pitch and yaw angle rotations.

Abstract: In a current overload protection circuit, a full wave rectifier bridge circuit is connected between an AC or DC power source to supply AC or DC power to a load through the output circuit of a solid-state relay. A current sensing resistor is connected across the DC terminals of the bridge circuit to sense the magnitude of the current flowing through the load. When an overload fault occurs, the voltage developed across the current sensing resistor will trigger a shunt regulator to turn on an optical isolation circuit, which upon being turned on will discharge a capacitor in an RC timing circuit. The discharge of the capacitor and the RC timing circuit triggers a Schmidt trigger circuit, which cuts off current flow to the input circuit of the solid-state relay, thereby cutting off current to the load. The shunt regulator then turns off de-energizing the optical isolator which, upon being de-energized, causes the current discharge path of the capacitor to be interrupted.

Abstract: A process of manufacturing a flexible metallized polymer film cover which provides environmental protection of electronic assemblies such as circuit card assemblies which are susceptible to external environmental factors which can impede functional performance and reduce reliability. The use of a metallized polymer film in the form of a two layer film, with two intimately bonded layers one being electrically insulative and the other metallic, provides environmental and electrical protection of the enclosed assembly.

Abstract: A method of forming a radiation hardened SOI structure is disclosed. The buried oxide layer of an SOI structure is hardened prior to the bonding of a device wafer which forms the silicon portion of the silicon-on-insulator. The radiation hardening is done by implantation of recombination center-generating impurities. All the radiation hardening is done prior to the bonding of the device silicon layer and allows for radiation hardening of the buried oxide layer of an SOI structure without any damage to the silicon device layer.

Abstract: A process to form poly sidegate LDD structures on buried channel MOSFETs is described. A polysilicon spacer is formed on the gate after source/drain processing. The spacer is later shorted to the main gate by implantation of neutral impurities. The process is particularly suited for SOI technology.