Abstract: A precision digital phase shift element for achieving precise phase shift of an input pulse train signal. The output is a pulse train at a frequency equal to the input signal frequency divided by N, and having N equally spaced phase states. The relative phase state of the output signal is reliably controlled by selective deletion of pulses from the input signal pulse train. The selective deletion can be achieved by selectively gating the input pulse train, or by use of a dual modulus frequency divider circuit.

Abstract: A multicell battery system includes at least two battery cells, and a selective cell bypass for each of the battery cells. Each cell bypass includes a metal-oxide-semiconductor field effect transistor (MOSFET) having a source, a drain, and a gate, a first electrical interconnection from the MOSFET source to a first side of the battery cell, a second electrical interconnection from the MOSFET drain to a second side of the battery cell, and an activation circuit connected to the MOSFET gate. The activation circuit includes an AND gate having as one input an AC square wave signal and as a second input a selection signal, a capacitor connected to the AND gate output signal, and a cascade voltage doubling circuit having an input in communication with a second electrode of the capacitor and an output in communication with the MOSFET gate.

Abstract: A corona source suitable for use in vehicle ignition systems uses a conductive coil that receives an RF input at one end and has a corona discharge site at the other end, with a reference electrode capacitively coupled to the coil. The pitch and the length of the coil are selected to produce a corona discharge in response to an RF input signal at a predetermined frequency and voltage, through quarter wavelength resonation. Either the new resonant coil or other corona discharge devices can be used to remediate fluid-borne wastes by initiating and sustaining RF corona discharges within the fluid. The pulses used to initiate the corona discharge preferably have alternating positive and negative components, with high initial voltages on the positive components to initiate the discharge, followed by lower positive voltage levels to sustain the discharge. Unipolar pulses, preferably with progressively decreasing voltage levels, can also be used.

Abstract: Microwave ports and low-frequency ports of a microwave enclosure are configured to realize high return losses and low insertion losses and suppress resonance modes below a predetermined microwave frequency. The microwave ports include microwave transmission lines which have first and second microstrip portions and a stripline portion which connects the first and second microstrip portions. The microwave transmission lines are positioned with the stripline portion received in a housing aperture. The low-frequency ports include a dielectric member and a plurality of metallic signal lines carried within the dielectric member. The dielectric member is relieved to expose inner and outer ends of the signal lines. The connector systems are received in housing apertures with metallic members positioned through the dielectric members and across the connector apertures to electrically partition the connector apertures into subapertures which each have a predetermined microwave cutoff frequency.

Abstract: A transponder detection system for detecting the presence at a detection area of a vehicle on which the transponder is mounted. Two antenna arrays are located on opposite sides of the detection area, and have their boresights directed to the detection area. For each array, a sum and difference signal of signals received from the transponder are measured. The sum channel signal is used to establish whether a transmission has occurred, and the difference channel signal is used to isolate any transponder that is at the detection area.

Abstract: A metal system that can be adjusted to obtain higher alloying temperatures in AlInAs/GaInAs heterostuctures is disclosed. Increasing the thickness of a Ag layer in the metal system facilitates higher alloying temperatures and, consequently, improved ohmic contact reliability. The system is particularly directed to use in Al.sub.x In.sub.1-x As/Ga.sub.0.47 In.sub.0.53 As with 0.48<x<1 power HFETs.

Abstract: A narrow bandwidth Bragg grating reflector comprises at least two Bragg reflection gratings positioned to form a Fabry-Perot etalon, with an optical gain medium between them. The etalon formed by the Bragg gratings has a reflection frequency spectrum that exhibits a plurality of primary peaks and nulls. The distance between the Bragg gratings is adjusted so that a predetermined design frequency falls within the bandwidth of one of the nulls, and the optical gain medium is chosen to provide optical gain for light at the design frequency. This establishes a secondary reflection peak in the Bragg grating etalon, centered on the design frequency, with a bandwidth that is narrower than those of the individual Bragg gratings and primary reflection peaks. In a preferred embodiment, the Bragg gratings are formed in the core of an optical fiber that is doped to provide optical gain at the predetermined optical frequency.

Abstract: Submicron channel length FET is fabricated using larger (e.g., 1 micron) design rule fabrication equipment. A polysilicon layer (34) is first formed over an active device region (28). The following transistor elements are then sequentially formed using a single mask opening (38): [1] threshold adjust implant (40) by implanting impurity ions into the active device region surface; [2] LDD implant regions (42) by implanting impurity ions into lower portion of the polysilicon layer (38); and [3] source/drain doped implant regions (44) by implanting impurity ions into the upper portion of polysilicon layer (38). A gate opening (60) is next formed in the polysilicon layer (38) and overlying dielectric layer (57) using large design rule lithography to pattern, and then by etching. Sidewall spacers (66) are formed at a submicron distance apart in the gate opening (60), defining gate length (68) therebetween.

Abstract: A system (36, 98) for determining the linearity of an RF detector (46, 106). A first technique involves combining two RF signals from two stable local oscillators (38, 40) to form a modulated RF signal having a beat frequency, and applying the modulated RF signal to a detector (46) being tested. The output of the detector (46) is applied to a low frequency spectrum analyzer (48) such that a relationship between the power levels of the first and second harmonics generated by the detector (46) of the beat frequency of the modulated RF signal are measured by the spectrum analyzer (48) to determine the linearity of the detector (46). In a second technique, an RF signal from a local oscillator (100) is applied to a detector (106) being tested through a first attenuator (102) and a second attenuator (104).

Abstract: Low cost broadband infrared windows are fabricated using a near net shape process which greatly reduces the cost of machining and grinding window materials. The fabrication of zinc sulfide (ZnS) IR windows uses ceramic powder processing to avoid the expensive prior art chemical vapor deposition method. Further, the invention involves a means of hardening and strengthening ZnS as part of the powder process, with IR transmission performance comparable to undoped CVD-prepared ZnS. The compositional modification used in the practice of the invention involves the introduction of gallium sulfide (Ga.sub.2 S.sub.3) as a second phase which acts to toughen and harden the ZnS. The process of the present invention achieves a hardening effect without degrading the IR transmission properties also by means of controlling the polycrystalline microstructure grains to a very small size. At the same time, porosity, which strongly degrades IR transmission, is minimized by full densification.

Abstract: A vertical interconnect structure comprising a three-wire-line transmission line structure for providing electrical continuity between different levels of a multilevel substrate. The present invention provides a means for transferring power between various levels of the substrate without introducing excessive additional RE losses. First and second coplanar transmission line structures are disposed on first and second surfaces of the substrate. A vertical interconnect structure is disposed in the multilevel RF substrate and is coupled between the first and second transmission line structures. The vertical interconnect structure comprises three conductors having predetermined cross-sectional dimensions and predetermined separations therebetween that are adapted to transfer RE power between the first and second transmission line structures.

Abstract: Passivating coatings are formed on populated electronic boards, such as a sealed chip on board electronic module, or the like, using a high density plasma deposition method that employs an electron cyclotron resonance (ECR) reactor. A populated electronic board is disposed in the electron cyclotron resonance reactor. A high density nitride plasma is generated by means of electron resonance in the reactor. The plasma is formed adjacent to a magnetic field coil where an ECR condition is established. The high density plasma forms a passivating coating that covers the populated electronic board with a silicon nitride passivating layer. To form the plasma, a mixture of silane and ammonia may be injected into the reactor to produce excited atoms that form a substantially oxygen-free nitride passivating coating.

Abstract: A membrane probe (10) for simultaneously testing two or more alternate columns or rows of integrated circuit chips (14) on the processing wafer (12) includes a flexible transparent and self planarizing membrane (22). The membrane includes circuit traces (26) and is carried by a substrate (16) defining parallel ports (18) corresponding to alternate columns or rows of circuit chips (14). Active test circuitry units (48) are mounted on the substrate (16) to perform test functions close to the site of testing. Two probes (10,110) are employed for testing each full wafer. One membrane probe (10) contains ports (18) and membrane segments (22) corresponding to one set of chips on the processing wafer, while the other probe (110) containing ports (18) and membrane segments (22) for the other interlaced set of chips on the wafer. Contact pads (34) are provided on areas of the membrane traces (26) to be visually registered through the membrane with contact pads of the chips under test.

Abstract: CO.sub.2 jet spray cleaning apparatus that monitors CO.sub.2 snow plume characteristics. The present invention is a CO.sub.2 jet spray cleaning system that comprises a holding tank for containing liquid CO.sub.2, a spray nozzle coupled to the holding tank, a valve coupled between the holding tank and the spray nozzle, and a temperature sensor coupled to the nozzle for sensing the temperature of a plume of CO.sub.2 that is sprayed by the nozzle and for providing a signal indicative thereof. The system may also comprise a display coupled to the temperature sensor for displaying the temperature of the plume of CO.sub.2 to an operator, or an alarm coupled to the temperature sensor for alerting an operator that the temperature of the plume of CO.sub.2 has risen to a predetermined level. Either the displayed signal or the alert signal indicates that the quality of the plume has diminished and that the liquid CO.sub.2 in the holding tank should be replenished. The present CO.sub.2 jet spray cleaning system and CO.

Abstract: A capacitor (20) is fabricated using a ferroelectric material (28) such as a layered perovskite material of the Aurivillius family. The capacitor (20) has a positive temperature coefficient (PTC) of capacitance. When used in an electrical device other than a memory device in place of a conventional capacitor, the PCT capacitor (20) provides inherent temperature compensation of the signal of the device when the device is operated at different temperatures below the Curie temperature of the ferroelectric material.

Abstract: Methods and systems for encoding a video signal into a bit stream, and for reconstructing the video signal from the bit stream are disclosed. In an embodiment of an encoder, an object encoder (22) assigns a symbolic code to an object contained in at least one video frame, wherein the symbolic code identifies a corresponding generic object from a set of generic objects. A difference processor (32), coupled to the object encoder (22), computes a difference signal in dependence upon a difference between the object and the corresponding generic object. A multiplexer (30) provides the bit stream based upon the difference signal and the symbolic code. In an embodiment of a decoder, a demultiplexer (82) extracts a symbolic code and a difference signal from the encoded video signal. The symbolic code identifies a corresponding generic object from a set of generic objects, and the difference signal represents a difference between an object and the corresponding generic object.

Abstract: A FIM system integrates data from a plurality of interconnected local databases to provide users with access to a virtual database. The FIM includes a user interface for generating a global query to search the virtual database, a smart dictionary database (SDD) that contains configuration data, a data information manager (DIM) that decomposes the global query into local queries, and a plurality of local information managers (LIMs) that execute the local queries to search for and retrieve data from the enumerated databases. A filter generates a list of those local databases that contain information relevant to the global query. As a result, the DIM only generates local queries for the enumerated local databases. An input translator converts the global query into the respective local formats for the local databases so that the FIM provides true integration of heterogeneous databases.

Abstract: A simple robust sensor probe for determining the magnesium concentration in molten metal alloys in real-time. The probe provides needed process control information in molten metal technologies and has particular application to processes for removing magnesium impurities from scrap aluminum. The probe employs a specially constructed electrochemical concentration cell adapted for repeated immersions into vessels containing molten metal alloys. Specifically, the probe comprises two electrodes, both inert to a molten salt layer, to the molten metal (aluminum), and to magnesium. One electrode comprises an inverted molybdenum cup, a magnesium reference material, and a fibrous ceramic wick, e.g., yttrium oxide, for retaining molten salt therein in contact with the magnesium reference material when the sensor probe is first inserted into the molten salt layer and then into the molten aluminum layer.

Abstract: A linear systolic array of computation cells, each cell having several vector rotation stages. These stages are programmable to provide efficient implementation of a variety of matrix algorithms. All data movement between cells is via parameterized data packets, and the full linear systolic array is completely data flow driven at the packet level. Physical computation cells can be mapped to act as one or more logical computation cells, allowing a small array to function logically as a larger array through a logical folding. This mapping also allows defective cells to be bypassed for fault tolerance. The array can be used to compute adaptive weights in digital beamforming radar applications.

Abstract: Contaminants are cleaned from the surface of a body in space by generating a substantially space-charge neutral reactive plasma, directing the plasma onto the contaminated surface at an energy below the surface sputtering energy (typically 20 eV), and reacting the plasma with the contaminants to remove them. A helicon wave plasma source is made light weight and compact enough for spacecraft use, with a plasma energy low enough to avoid damaging optical surfaces, by using permanent magnets to establish a static axial magnetic field, and a simple but novel rf antenna design. The antenna consists of a pair of spaced conductive rings which extend around the plasma tube, with conductive base and rf feed bars extending between the rings on diametrically opposite sides. The feed bar is interrupted to provide an rf input on opposite sides of the interruption. The antenna is preferably formed as an integral metal unit, with its rings rigidly supported by and integral with opposite ends of the base bar.