Semiconductors & ICs

FETs Based on Doped Polyaniline/Polyethylene Oxide Fibers

Advantages include tailorability of electronic properties and low power demands. A family of experimental highly miniaturized field-effect transistors (FETs) is based on exploitation of the electrical properties of nanofibers of polyaniline/ polyethylene oxide (PANi/PEO) doped with camphorsulfonic acid. These polymer-based FETs have the potential for becoming building blocks of relatively inexpensive, low-voltage, high-speed logic circuits that could supplant complementary metal oxide/semiconductor (CMOS) logic circuits.

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Carbon-Nanotube Schottky Diodes

These devices can outperform conventional Schottky diodes at submillimeter wavelengths. Schottky diodes based on semiconducting single-walled carbon nanotubes are being developed as essential components of the next generation of submillimeter- wave sensors and sources. Initial performance predictions have shown that the performance characteristics of these devices can exceed those of the state-of-the-art solid-state Schottky diodes that have been the components of choice for room-temperature submillimeter- wave sensors for more than 50 years.

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Dual Common Planes for Time Multiplexing of Dual-Color QWIPs

With external control, commercial single-color readout integrated circuits could be used. A proposed improved method of externally controlled time multiplexing of the readouts of focal plane arrays of pairs of stacked quantum well infrared photodetectors (QWIPs) that operate in different wavelength bands is based on a dual detector common plane circuit configuration. The method would be implemented in a QWIP integrated-circuit chip hybridized with a readout integrated circuit (ROIC) chip.

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MMIC Power Amplifier Puts Out >40 mW From 75 to 110 GHz

This amplifier operates over the full frequency band of the WR-10 waveguide. A three-stage monolithic microwave integrated circuit (MMIC) W-band amplifier has been constructed and tested in a continuing effort to develop amplifiers as well as oscillators, frequency multipliers, and mixers capable of operating over wide frequency bands that extend above 100 GHz. There are numerous potential uses for MMICs like these in scientific instruments, radar systems, communication systems, and test equipment operating in this frequency range. This amplifier can be characterized, in part, as a lower-frequency, narrower band, higher-gain version of the one described in “Power Amplifier With 9 to 13 dB of Gain from 65 to 146 GHz” (), NASA Tech Briefs, Vol. 25, No. 1 (January 2001), page 44. This amplifier includes four InP high-electron-mobility transistors (HEMTs), each having a gate periphery of 148 µm. In the third amplifier stage, two of the HEMTs are combined in parallel to maximize the output power. The amplifier draws a current of 250 mA at a supply potential of 2.5 V.

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Multiplexing Transducers Based on Tunnel-Diode Oscillators

Compact, low-power transducers could operate over wide temperature ranges. Multiplexing and differential transducers based on tunnel-diode oscillators (TDOs) would be developed, according to a proposal, for operation at very low and/or widely varying temperatures in applications that involve requirements to minimize the power and mass of transducer electronic circuitry. It has been known since 1975 that TDOs are useful for making high-resolution (of the order of 10–9) measurements at low temperatures. Since that time, TDO transducers have been found to offer the following additional advantages, which the present proposal is intended to exploit:

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Silicon-Based Optical Modulator With Ferroelectric Layer

This device would remain switched even with power turned off. According to a proposal, a silicon dioxide layer in a high speed, low power, silicon-based electro-optical modulator would be replaced by a layer of lead zirconate titanate or other ferroelectric oxide material. The purpose of this modification is to enhance the power performance and functionality of the modulator.

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