Abstract: Digital logic comprising a high speed analog to digital converter, a high speed analog to digital converter, a digital multiplier, and an infinite impulse response filter and decimation circuit are used to digitize a magnetic signal that is subsequently processed by magnetic data processing algorithms. The high resolution digital to analog converter is directly incorporated in a feedback loop of a magnetometer sensor, and an expensive precision analog to digital converter is replaced by a less expensive, lower power digital to analog converter. The improvement provided by the present invention includes a high speed analog to digital converter coupled between the oscillator and a first input of a multiplier, and a second analog to digital converter that is coupled between the sense coil of the sensor and a second input of the multiplier. The output of the multiplier is coupled to an infinite impulse response filter and decimation circuit that produces the digital output signal from the magnetometer.

Abstract: A Sigma Rho A/D converter (10) includes a transconductance element (R) having an input node for receiving an input voltage signal V.sub.in and an output node providing an analog current I.sub.in ; a charge integrator (12) having an input coupled to the output node, the charge integrator having feedback provided by an integrating capacitor C and an output node providing an output signal V.sub.o ; and a clocked voltage comparator (14) having an input coupled to V.sub.o for comparing V.sub.o to a reference potential. An output of the comparator updates in response to an occurrence of a first clock signal CLK1. A current sink (16) is switchably coupled to the output node of the transconductance element as a function of the logic state of the output of the comparator.

Abstract: An improved method for soldering a thermoelectric cooler between an electronic device and a heatsink. Thermoelectric coolers are assembled by soldering parts together using a first solder. The bottom surface of the thermoelectric cooler is first soldered to the heatsink using a second solder and then the top surface is soldered to the electronic device using a third solder preferably having the same melting point as the second solder, or having approximately the same melting point as the second solder. Reverse powering of the thermoelectric cooler assists the soldering of the top surface to the electronic device by heating the top surface to a temperature sufficient to melt the third solder while cooling the bottom surface of the thermoelectric cooler to a temperature lower than the melting point of the second solder.

Abstract: The present invention provides a method and apparatus for metallizing vias in co-fired ceramic green tape. A vacuum operated pick and place anvil comprising a porous block is used to pick up conductor balls from a bed. Air pressure is used to create a vacuum which pulls the conductor balls to the porous block. A stencil having openings is placed on a contact surface of the anvil, thereby permitting only one conductor ball to attach to each opening in the stencil. With the conductor balls attached to the anvil, the anvil is lowered onto the green tape. Next the anvil pushes the conductor balls into the tape until the conductor balls break through the opposite side of the tape. The anvil is retracted leaving the conductor balls lodged in the tape. It is possible to provide a green tape with pre-formed vias so that forcing the conductor balls into the tape is a simpler task.

Abstract: Substantial amounts of particulate soils in garments can be removed by agitation in gas-jet in a solvent-free, low-pressure environment. The ability of the present gas-jet agitation system to remove particulate soils from garments and fabrics rivals that of conventional dry-cleaning processes which agitate the garments and fabrics while immersed in solvent. Thus, a dry-cleaning operation may consist of a solvent-immersion step for removing soluble soils and a gas-jet agitation step to remove particulates. Considerable savings in equipment and operating costs may be realized in the practice of the invention, since solvent flow rates need not be boosted to provide necessary agitation for particulate soil removal. The savings achievable by employing gas-jet agitation are even more pronounced in dense phase gas dry cleaning systems, which require pressurized environments to maintain a liquified solvent.

Abstract: A phase shifter that employs digital circuitry to achieve arbitrarily fine phase control of reference signals at frequencies extending to the Gigahertz region. The phase shifter includes a cascade of identical phase shift units that provide progressively finer phase control resolution over a full 360 degree range. The phase precision is set by the number of stages used.

Abstract: A high frequency microwave integrated circuit assembly (14,20) includes a fragile monolithic microwave integrated circuit (MMIC) chip (22) mounted in an MMIC subassembly (20) that is completely assembled, tested and burned in independent of the main high frequency microwave integrated circuit assembly and is mechanically attached to the main assembly by a captivation screw (100). The MMIC chip (22) is bonded to an uppermost tier (30) of a multi-tier spaced pedestal (26) and is received within an aperture (46) within a slave board (44) that itself is mounted and bonded to a lower tier (28) of the pedestal (26). The main integrated circuit assembly is formed with a rectangular opening (84) in an upper portion of its substrate to non-rotationally receive the rectangular slave board and a slightly larger internally threaded circular hole (94) in a lower portion of the main assembly substrate that threadedly receive the captivation screw (100).

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 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: 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: 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: 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 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: 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: 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.