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Gaier, T.

Publications and source records attributed to Gaier, T..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

W-band Heterodyne Receiver Module with 27 K Noise Temperature

We present noise temperature and gain measurements of a W-band heterodyne module populated with MMIC LNAs designed and fabricated using 35nm InP HEMT process. The module has a WR-10 waveguide input. GPPO connectors are used for the LO input and the I and and Q IF outputs. The module is tested at both ambient (300 K) and cryogenic (25 K) temperatures. At 25 K physical temperature, the module has a noise temperature in the range of 27-45 K over the frequency band of 75-111 GHz. The module gain varies between 15 dB and 27 dB. The band-averaged module noise temperature of 350 K and 33 K were measured over 80-110 GHz for the physical temperature of 300 K and 25 K, respectively. The resulting cooling factor is 10.6.

heterodyne module↗
NASA NTRS2012

The QUIET Instrument

The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the Cosmic Microwave Background, targeting the imprint of inflationary gravitational waves at large angular scales ( approx 1 deg.) . Between 2008 October and 2010 December, two independent receiver arrays were deployed sequentially on a 1.4 m side-fed Dragonian telescope. The polarimeters which form the focal planes use a highly compact design based on High Electron Mobility Transistors (HEMTs) that provides simultaneous measurements of the Stokes parameters Q, U, and I in a single module. The 17-element Q-band polarimeter array, with a central frequency of 43.1 GHz, has the best sensitivity (69 micro Ks(exp 1/2)) and the lowest instrumental systematic errors ever achieved in this band, contributing to the tensor-to-scalar ratio at r < 0.1. The 84-element W-band polarimeter array has a sensitivity of 87 micro Ks(exp 1/2) at a central frequency of 94.5 GHz. It has the lowest systematic errors to date, contributing at r < 0.01 (QUIET Collaboration 2012) The two arrays together cover multipoles in the range l approximately equals 25-975 . These are the largest HEMT-ba.sed arrays deployed to date. This article describes the design, calibration, performance of, and sources of systematic error for the instrument,

Gaier, T.↗
NASA NTRS2011

Getting the GeoSTAR Instrument Concept Ready for a Space Mission

The Geostationary Synthetic Thinned Array Radiometer - GeoSTAR - is a microwave sounder intended for geostationary satellites. First proposed for the EO-3 New Millennium mission in 1999, the technology has since been developed under the Instrument Incubator Program. Under IIP-03 a proof-of-concept demonstrator operating in the temperature sounding 50 GHz band was developed to show that the aperture synthesis concept results in a realizable, stable and accurate imaging-sounding radiometer. Some of the most challenging technology, such as miniature low-power 183- GHz receivers used for water vapor sounding, was developed under IIP-07. The first such receiver has recently been adapted for use in the High Altitude MMIC Sounding Radiometer (HAMSR), which was previously developed under IIP-98. This receiver represents a new state of the art and outperforms the previous benchmark by an order of magnitude in radiometric sensitivity. It was first used in the GRIP hurricane field campaign in 2010, where HAMSR became the first microwave sounder to fly on the Global Hawk UAV. Now, under IIP-10, we will develop flight-like subsystems and a brassboard testing system, which will facilitate rapid implementation of a space mission. GeoSTAR is the baseline payload for the Precipitation and All-weather Temperature and Humidity (PATH) mission - one of NASA's 15 "decadal-survey" missions. Although PATH is currently in the third tier of those missions, the IIP efforts have advanced the required technology to a point where a space mission can be initiated in a time frame commensurate with second-tier missions. An even earlier Venture mission is also being considered.

millimeter-wave↗
NASA NTRS2008

First On-Wafer Power Characterization of MMIC Amplifiers at Sub-Millimeter Wave Frequencies

Recent developments in semiconductor technology have enabled advanced submillimeter wave (300 GHz) transistors and circuits. These new high speed components have required new test methods to be developed for characterizing performance, and to provide data for device modeling to improve designs. Current efforts in progressing high frequency testing have resulted in on-wafer-parameter measurements up to approximately 340 GHz and swept frequency vector network analyzer waveguide measurements to 508 GHz. On-wafer noise figure measurements in the 270-340 GHz band have been demonstrated. In this letter we report on on-wafer power measurements at 330 GHz of a three stage amplifier that resulted in a maximum measured output power of 1.78mW and maximum gain of 7.1 dB. The method utilized demonstrates the extension of traditional power measurement techniques to submillimeter wave frequencies, and is suitable for automated testing without packaging for production screening of submillimeter wave circuits.

monolithic microwave integrated circircuit↗
NASA NTRS2006

Demonstration of a Sub-Millimeter Wave Integrated Circuit (S-MMIC) using InP HEMT with a 35-nm Gate

In this paper, we present two single stage MMIC amplifiers with the first demonstrating a measured S21 gain of 3-dB at 280-GHz and the second demonstrating 2.5-dB gain at 300- GHz, which is the threshold of the sub-millimeter wave regime. The high-frequency operation is enabled by a high-speed InP HEMT with a 35-nm gate. This is the first demonstrated S21 gain at sub-millimeter wave frequencies in a MMIC.

millimeter - wave↗
NASA NTRS2003

MMIC HEMT radiometry

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MMIC HEMT radiometry↗
NASA NTRS2002

W-band InP based HEMT MMIC low noise amplifiers

This paper presents the designs and measurement results of a three-stage and a four-stage W-band monolithic microwave integrated circuits (MMIC) including a three-stage and a four-stage low noise amplifiers.

monolithic microwave integrated circuits low noise↗
NASA NTRS2000

Cryogenic MMIC Low Noise Amplifiers

Monolithic (MMIC) and discrete transistor (MIC) low noise amplifiers are compared on the basis of performance, cost, and reliability. The need for cryogenic LNA's for future large microwave arrays for radio astronomy is briefly discussed and data is presented on a prototype LNA for the 1 to 10 GZH range along with a very wideband LNA for the 1 to 60 GHz range.

MMIC Low-noise amplifier↗