Semiconductors & ICs

Board Saver for Use With Developmental FPGAs

A printed-circuit board is protected against repeated soldering and unsoldering.

A device denoted a board saver has been developed as a means of reducing wear and tear of a printed-circuit board onto which an antifuse field-programmable gate array (FPGA) is to be eventually soldered permanently after a number of design iterations. The need for the board saver or a similar device arises because (1) antifuse- FPGA design iterations are common and (2) repeated soldering and unsoldering of FPGAs on the printed-circuit board to accommodate design iterations can wear out the printed-circuit board. The board saver is basically a solderable/unsolderable FPGA receptacle that is installed temporarily on the printed-circuit board.

Posted in: Briefs, Semiconductors & ICs, Integrated circuits, Protective structures
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Digital Synchronizer Without Metastability

A proposed design for a digital synchronizing circuit would eliminate metastability that plagues flip-flop circuits in digital input/output interfaces. This metastability is associated with sampling, by use of flip-flops, of an external signal that is asynchronous with a clock signal that drives the flip-flops: it is a temporary flip-flop failure that can occur when a rising or falling edge of an asynchronous signal occurs during the setup and/or hold time of a flip-flop.

Posted in: Briefs, Semiconductors & ICs
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Efficient Multiplexer FPGA Block Structures Based on G⁴FETs

Fewer G4FETs than conventional transistors would be needed to implement multiplexers.

Generic structures have been conceived for multiplexer blocks to be implemented in field-programmable gate arrays (FPGAs) based on four-gate field-effect transistors (G4FETs). This concept is a contribution to the continuing development of digital logic circuits based on G4FETs and serves as a further demonstration that logic circuits based on G4FETs could be more efficient (in the sense that they could contain fewer transistors), relative to functionally equivalent logic circuits based on conventional transistors.

Posted in: Briefs, TSP, Semiconductors & ICs
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VLSI Microsystem for Rapid Bioinformatic Pattern Recognition

Rapid processing is made possible by a massively parallel neural-computing architecture.

A system comprising very-large-scale integrated (VLSI) circuits is being developed as a means of bioinformatics-oriented analysis and recognition of patterns of fluorescence generated in a microarray in an advanced, highly miniaturized, portable genetic-expression- assay instrument. Such an instrument implements an on-chip combination of polymerase chain reactions and electrochemical transduction for amplification and detection of deoxyribonucleic acid (DNA).

Posted in: Briefs, TSP, Semiconductors & ICs
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Low-Noise Amplifier for 100 to 180 GHz

Noise temperature is lower than in the prior state of the art.

A three-stage monolithic millimeter-wave integrated-circuit (MMIC) amplifier designed to exhibit low noise in operation at frequencies from about 100 to somewhat above 180 GHz has been built and tested. This is a prototype of broadband amplifiers that have potential utility in diverse applications, including measurement of atmospheric temperature and humidity and millimeter-wave imaging for inspecting contents of opaque containers.

Posted in: Briefs, Semiconductors & ICs, Optimization, Amplifiers, Integrated circuits
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T/R Multi-Chip MMIC Modules for 150 GHz

A transmitting gain of 14 dB at 150 GHz has been demonstrated.

Modules containing multiple monolithic microwave integrated-circuit (MMIC) chips have been built as prototypes of transmitting/receiving (T/R) modules for millimeter-wavelength radar systems, including phased-array radar systems to be used for diverse purposes that could include guidance and avoidance of hazards for landing spacecraft, imaging systems for detecting hidden weapons, and hazard-avoidance systems for automobiles. Whereas prior landing radar systems have operated at frequencies around 35 GHz, the integrated circuits in this module operate in a frequency band centered at about 150 GHz. The higher frequency (and, hence, shorter wavelength), is expected to make it possible to obtain finer spatial resolution while also using smaller antennas and thereby reducing the sizes and masses of the affected systems.

Posted in: Briefs, TSP, Semiconductors & ICs, Downsizing, Amplifiers, Antennas, Integrated circuits, Radar
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Some Improvements in Utilization of Flash Memory Devices

Two developments improve the utilization of flash memory devices in the face of the following limitations: (1) a flash write element (page) differs in size from a flash erase element (block), (2) a block must be erased before its is rewritten, (3) lifetime of a flash memory is typically limited to about 1,000,000 erases, (4) as many as 2 percent of the blocks of a given device may fail before the expected end of its life, and (5) to ensure reliability of reading and writing, power must not be interrupted during minimum specified reading and writing times.

Posted in: Briefs, Semiconductors & ICs
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GPS/MEMS IMU/Microprocessor Board for Navigation

A miniaturized instrumentation package comprising a (1) Global Positioning System (GPS) receiver, (2) an inertial measurement unit (IMU) consisting largely of surface-micromachined sensors of the microelectro-mechanical systems (MEMS) type, and (3) a microprocessor, all residing on a single circuit board, is part of the navigation system of a compact robotic spacecraft intended to be released from a larger spacecraft [e.g., the International Space Station (ISS)] for exterior visual inspection of the larger spacecraft. Variants of the package may also be useful in terrestrial collision-detection and -avoidance applications.

Posted in: Briefs, TSP, Semiconductors & ICs
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InP Heterojunction Bipolar Transistor Amplifiers to 255 GHz

These amplifiers can be used in millimeter-wave imaging systems for weapons detection and airport security, and for radar instruments.

Two single-stage InP heterojunction bipolar transistor (HBT) amplifiers operate at 184 and 255 GHz, using Northrop Grumman Corporation’s InP HBT MMIC (monolithic microwave integrated circuit) technology. At the time of this reporting, these are reported to be the highest HBT amplifiers ever created. The purpose of the amplifier design is to evaluate the technology capability for high-frequency designs and verify the model for future development work.

Posted in: Briefs, Semiconductors & ICs, Amplifiers, Integrated circuits, Transistors, Product development
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Submillimeter-Wave Amplifier Module With Integrated Waveguide Transitions

This technique can be used in submillimeter-wave imaging in homeland security, weapons detection, and commercial test equipment.

To increase the usefulness of monolithic millimeter-wave integrated circuit (MMIC) components at submillimeter-wave frequencies, a chip has been designed that incorporates two integrated, radial E-plane probes with an MMIC amplifier in between, thus creating a fully integrated waveguide module. The integrated amplifier chip has been fabricated in 35-nm gate length InP high-electron-mobility-transistor (HEMT) technology. The radial probes were mated to grounded coplanar waveguide input and output lines in the internal amplifier. The total length of the internal HEMT amplifier is 550 μm, while the total integrated chip length is 1,085 μm. The chip thickness is 50 μm with the chip width being 320 μm.

Posted in: Briefs, TSP, Semiconductors & ICs, Amplifiers, Integrated circuits, Waveguides
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