Abstract: An active filter circuit component includes an all NPN bipolar tunable Gm cell and a positive current source (PCS) for supplying common mode current. The tunable Gm cell includes a fixed Gm cell having transconductance G.sub.f, a current divider and recombination circuit that together effectively multiply G.sub.f by a tuning factor .alpha., where -1.ltoreq..alpha..ltoreq.1, without effecting the cell's common mode current I.sub.cm. The PCS includes a pair of unity gain inverting single ended amplifiers that are connected in antiparallel across a pair of matched resistors. Alternately, the resistors can be connected across the inverting and non-inverting sides of a differential amplifier. A constant voltage is applied across the resistors to supply I.sub.cm, while maintaining a common mode resistance of R/2 and a differential mode resistance approaching infinity.

Abstract: An apparatus for measuring the properties of the tropopause includes a variable frequency microwave radiometer operating over a range of from about 118.0 to about 119.0 GHz. The radiometer receives as an input a frequency selector signal and produces as an output a measured power level at a measurement frequency corresponding to the input frequency selector signal. The apparatus further includes a feedback controller having as an input the measured power level and producing as an output the frequency selector signal. The feedback controller varies the frequency selector signal to a target frequency so as to produce a minimum value in the measured power level. The tropopause equivalent altitude is determined from the target frequency.

Abstract: An epitaxial structure and method of manufacture for a field-effect transistor capable of high-speed low-noise microwave, submillimeterwave and millimeterwave applications. Preferably, the epitaxial structure includes a donor layer and/or buffer layer made from a semiconductor material having the formula AlP.sub.0.39+y Sb.sub.0.61-y.

Abstract: The number of input latching comparators in a flash analog-to-digital converter is significantly reduced by merging the input latching function into exclusive OR gates used in the converter's decoding section. A latching exclusive OR gate used for this purpose employs resonant tunneling diodes as the latching devices, with hysteresis and impedance elements connected to ensure that the gate latches in a logic state that corresponds to the input analog signal. The latching logic gates operate in a current mode, enabling updated logic states to be latched in response to a periodic clock signal.

Abstract: A monolithically integrated solar cell microarray includes an isolation layer or multiple isolation layers between a substrate and a solar cell layer, and a trench in the solar cell layer that exposes the isolation layer. Together the isolation layer and trench define solar cells that are spaced apart and electrically isolated on the monolithic substrate. The solar cells are scaled to provide a desired current. Base contacts and integral emitter contact/interconnects connect a number of the scaled solar cells in series to sum their voltages to supply a desired output voltage and current. The trench and integral emitter contact/interconnects are formed using photolithographic etching and liftoff processes, respectively, which are much quicker and less expensive than the conventional dicing and soldering processes.

Abstract: A spacecraft telescope door (10) adapted for use with remote sensing devices requiring optical and infrared calibration. The door (10) includes a first calibration surface (24) disposed on a first panel (14) for providing a radiant temperature reference for infrared calibrations. A second calibration surface (26) is disposed on a second panel (12) for providing an absolute radiance reference for optical calibrations. A panel hinge (16) controls the relative position of the panels (12,14) with respect to each other, and an aperture hinge (20) controls the relative position of the panels with respect to the aperture (28). In a specific embodiment, the first surface (24) is painted with chemglaze Z306, a highly emissive paint with a low reflectance for facilitating infrared calibration. The second surface (26) is painted with YB71, a diffuse reflective paint for facilitating optical calibration.

Abstract: Diamondlike carbon is deposited on a deposition substrate in a deposition apparatus that can be evacuated and backfilled with a carbonaceous gas. A plasma is generated in the gas by heating a filament within the chamber to produce electrons, and positively biasing the filament with respect to the deposition chamber wall to accelerate the electrons into the carbonaceous gas. The carbonaceous gas dissociates and ionizes in the resulting plasma to produce positively charged carbon ions. A deposition substrate within the chamber is negatively biased with respect to the deposition chamber wall, accelerating the carbon ions so that they are deposited onto the surface of the substrate.

Abstract: An arrangement of an automotive lamp assembly is provided including a reflector housing with a central opening; a discharge light assembly mounted to the reflector through the opening; a base supporting the discharge light assembly in the reflector, the base having a concentric conductor connected to the discharge light assembly at one end and a pin first terminal on an opposite end of the first conductor, and the base having a second eccentric conductor connected to the discharge light assembly on one end with a collar connected on an opposite end; a socket sealed with the base, the socket having a concentric conductor for mating with the base concentric conductor, the socket concentric conductor having a collar terminal at a first end toward the base and a blade terminal at a second opposite end, the socket also having an eccentric conductor having a collar terminal at a first end toward the base and a blade end at a second opposite end; an annular high voltage insulation member surrounding the first end of

Abstract: A sequential messaging method for use in a vehicle detector and classification system having a processor and that uses first and second beams to detect transitions of front and rear ends of a vehicle. The method comprises detecting the vehicle when its front end breaks the first beam, assigning a new vehicle ID number to the vehicle, and transmitting a vehicle detection report containing the vehicle ID number to the processor. The vehicle is detected when its front end passes the second beam, and a vehicle detection update report is transmitted to the processor comprising left edge position, right edge position, range to each edge, vehicle height, and vehicle speed, all of which are derived from the beams reflected from the vehicle. The vehicle is detected when its rear end passes the first beam, and a rear vehicle detection report is transmitted to the processor comprising the left edge position, right edge position, range to each edge, vehicle height, and vehicle speed.

Abstract: Methods and systems for encoding data representative of a sequence of video frames for transmission to a decoder. A motion compensated predictive coder (24) substantially losslessly compresses the data, computes a motion vector, and forms an intermediate coded representation which includes the compressed data and the motion vector. A frame detector (26), which detects frames having a prediction error which exceeds a predetermined threshold, is coupled to the motion compensated predictive coder (24). A digital storage device (22) is coupled to the motion compensated predictive coder (24) and the frame detector (26). The digital storage device (22) stores the intermediate coded representation and stores a representation of the frames having the prediction error which exceeds the predetermined threshold. A lossless decoder (29), coupled to the digital storage device (22), substantially losslessly decodes the intermediate coded representation to form a decoded representation.

Abstract: Disclosed is a tuned resonant oscillating mass pump, and particularly a pump structure and assembly which can be conveniently and readily mounted inside automotive tires for the purposes of maintaining optimum tire pressure and generating of electrical power from the movement of the tuned oscillating mass in such pumps. The oscillating mass can be a pendulum or a freely moving weight or a ball rolling within an arcuate chamber.

Abstract: A glass-ceramic substrate for encapsulating an electronic component, with at least two shrinkage control layers restricting shrinkage of the substrate during a co-firing process. The shrinkage control layers are chosen so that they have substantially the same shrinkage characteristics, during co-firing, as the buried electronic component. This results in substantially no differential shrinkage between the electronic component and the substrate, along predetermined directions, during co-firing. In addition, the thermal expansion coefficients of the substrate, shrinkage control layers and electronic component are chosen so that they substantially match, such that their thermal-induced contraction during the cooling phase of the co-firing process substantially match. In the preferred embodiment, the electronic component is buried within the layers of an LTCC structure. The shrinkage control layers are preferably implemented as Al.sub.2 O.sub.3 or TiO.sub.

Abstract: A fiber-based delivery system and method for delivering pulsed high power optical radiation (14) over longer fiber lengths than prior fiber-based systems comprises a fiber bundle (10) and a beam launcher (12) that directs a high power optical beam (14) to an input end (18) of the fiber bundle (10), and distributes it over the individual fibers (22) in the bundle. The number of fibers (22) is large enough so that substantially all of the individual fibers (22) are subjected to an optical intensity level below that required to induce substantial nonlinear optical losses. In addition, the diameters of the individual fiber cores (34) are small enough so that the modal dispersion experienced by the optical beam (14) does not exceed approximately 80 ns/km. In a preferred embodiment for transmission of pulsed 1.06 micron light, the fiber bundle (10) comprises 96 individual fibers (22), with respective core (34) diameters of approximately 600 microns, that are encapsulated in a jacketed adhesive (30).

Abstract: An improved system (30) for measuring surface aberrations of concave cylindrical surfaces. In the illustrative embodiment, the invention includes a transmission flat (20), an interferometer (32), and a surface to be measured (28). The transmission flat (20) is a transparent disc that is placed between the interferometer (32) and the surface (28) to be measured. An electromagnetic wave (33,34,36,37) is generated by the interferometer (32), and is directed through the transmission flat (20). The wave (41) bounces off the surface (28) to be measured and is retro-reflected off a first surface (26) of the transmission flat. The electromagnetic wave (42) returns to the opposite side of the surface (28) under test. The wave (43) then bounces off the surface (28) under test and passes through the transmission flat (20). The wave (43) interferes with light (39) that is reflected from a reference surface (26) of transmission flat (20) on a first bounce.

Abstract: A unique photoresist process is provided which achieves clean and complete lift-off of a thin film layer such as a sputtered thin film formed on a photoresist which is formed above a semiconductor substrate. The process of the present invention relies on a reentrant photoresist profile which breaks the continuity of the thin film layer. Accordingly, the process of the present invention ensures a clean lift-off. The desired photoresist profile which breaks the continuity of the thin film layer can be obtained by a typical photoresist process preceded by an oxidation process that takes place on the surface of the semiconductor substrate. The oxidation process provides a thin native oxide layer with thickness ranging from about 30 to 50 .ANG.. No extra processing steps involving dielectric film deposition and etch are required to achieve clean lift-off. Nevertheless, the process of the present invention ensures the clean lift-off of the thin film layer.

Abstract: A rotary connector comprising first and second printed wiring boards that rotate relative to each other and that are electrically interconnected using spring loaded pogo-stick type contacts. The spring-loaded contacts are used to transfer electrical signals or power to metallized rings or contacts formed on the first printed wiring board. The spring-loaded pogo-stick type contacts are very rugged and provide for a rotary connector having long life.

Abstract: Multiple solid precursor bubblers are used to alleviate channeling effects caused by high carrying gas flow rates to provide for deposition of indium-based epitaxial materials in high-capacity MOCVD reactor systems. Precracking of precursor materials that exhibit higher dissociation temperatures using heated manifolds or heated susceptor, and rotation of individual wafers in a multi-wafer reactor chamber enhance thickness uniformity, surface morphology and electronic properties of deposited epitaxial layers.

Abstract: Production of precision reflective mirror surfaces on low cost, lightweight molded plastic substrates (10). The process involves making a master pattern (12) having a precision machined contoured surface (13) corresponding to the precision mirror surface desired on the plastic substrate. A release layer (14) and a reflective layer (17) are applied to the master pattern and then transferred to the molded plastic substrate (10), with a curable replication layer (18) therebetween preferably comprising a filler-reinforced polymer composition which is compatible with the polymeric substrate and has a low coefficient of thermal expansion (CTE) which closely matches the CTE of the substrate. The replication layer (20) is cured to replicate the precision of the surface (13) of the master pattern (12), which can be reused to produce a multiplicity of high precision molded plastic mirrors (21).

Abstract: A unique pulse forming network assembly designed for use with a laser flashlamp. The inventive assembly includes a planar printed circuit board (14) to which a plurality of electrical energy storage elements (L1, C1) are mounted. The energy storage elements (L1, C1) are mounted on one side of the primed circuit board (14) so that the electrical contacts thereof extend therethrough. The contacts are wave soldered to complete the assembly. In a specific embodiment, the planar mounting of the energy storage elements (L1, C1) is enabled by the substitution of a conventional relay (K1) with a field effect transistor (Q1). The FET selectively connects the energy storage elements (L1, C1) to an output terminal of the network to activate the flashlamp. In a more specific embodiment, at least one of the energy storage elements is a capacitor (C1) which is connected to the housing (16) by a flange (18).

Abstract: A modular array processor architecture (10) comprising a plurality of interconnected parallel processing node (11)s that each comprise a control processor (12), an arithmetic processor (13) having an input port (22) for receiving data from an external source that is to be processed, a node memory (14) that also comprises a portion of a distributed global memory, and a network interface (15) coupled between the control processor (12), the arithmetic processor (13), and the node memory (14). Data and control buses (17, 18) are coupled between the arithmetic processors (13) and network interfaces (14) of each of the processing nodes (11). Respective network interfaces (15) link each of the arithmetic processors (13), node memories (14) and control processors (12) together to provide for communication throughout the architecture (10) and permit each node to communicate with the node memories (14) of all other processing nodes (11).