Showing papers by "Richard Lai published in 2010"
TL;DR: In this article, the authors present an amplifier module operating at a frequency of 0.48 THz, which represents almost a 50% increase in solid-state amplifier operating frequency compared to prior state of the art, and is the highest reported amplifier to date.
Abstract: In this letter, we present an amplifier module operating at a frequency of 0.48 THz. This represents almost a 50% increase in solid-state amplifier operating frequency compared to prior state of the art, and is the highest reported amplifier to date. The amplifier demonstrates a peak gain of 11.7 dB measured in a waveguide split-block housing. Sub 50-nm InP HEMT transistors with an estimated f MAX > 1 THz are used to achieve this level of performance. The five stage amplifier is realized in coplanar waveguide, and uses monolithically integrated dipole probes to couple the chip from the WR 2.2 waveguide.
105 citations
TL;DR: In this paper, a sub-millimeter wave solid-state power amplifier (SSPA) is implemented in coplanar waveguide (CPW) and uses an advanced high fMAX InP HEMT transistor with a sub 50-nm gate.
Abstract: In this paper, we demonstrate a packaged sub-millimeter wave solid-state power amplifier (SSPA). The SSPA is implemented in coplanar waveguide (CPW) and uses an advanced high fMAX InP HEMT transistor with a sub 50-nm gate. A monolithically integrated CPW dipole-to-waveguide transition eliminates the need for wirebonding and additional substrates. On-chip compact tandem couplers are used for power combining. The amplifier demonstrates 15-dB small-signal gain at 340 GHz. Peak saturated output power of 10 mW at 338 GHz is obtained at the waveguide flange out-put for the SSPA module.
68 citations
23 May 2010
TL;DR: In this paper, a 220 GHz solid-state power amplifier (SSPA) module is presented, which is implemented in coplanar waveguide (CPW) technology and uses sub 50 nm InP HEMT transistors.
Abstract: In this paper, a 220 GHz solid-state power amplifier (SSPA) module is presented. Eight-way on-chip power combining is used to achieve a saturated output power ≥ 50 mW over a 217.5 to 220 GHz bandwidth, representing a significant increase in SSPA output power at this frequency compared to prior state of the art. The amplifier MMIC is implemented in coplanar waveguide (CPW) technology and uses sub 50 nm InP HEMT transistors. Two levels of power combining, a 2∶1 tandem coupler and a 4∶1 Dolph-Chebychev transformer, are realized in CPW. The module demonstrates ≥ 11.5 dB small signal gain from 207 to 230 GHz. Saturated output power ≥ 40 mW was measured from 216 to 222.5 GHz.
43 citations
23 May 2010
TL;DR: In this paper, a geostationary thinned array sounder was used for low-noise measurements from the flanks of the 183 GHz water vapor line with a mass of 3 g while consuming 24 mW of power.
Abstract: Weather forecasting, hurricane tracking and atmospheric science applications depend on humidity sounding of atmosphere. Current instruments provide these measurements from ground based, airborne and LEO satellites by measuring radiometric temperature on the flanks of the 183 GHz water vapor line. We have developed miniature low noise receivers that will enable these measurements from a geostationary thinned array sounder. This geostationary instrument is based on hundreds of low noise receivers that convert the 180 GHz signal directly to baseband in-phase and in-quadrature signals for digitization and correlation. The developed receivers provided a noise temperature of 450 K from 165 to 183 GHz (NF=4.1 dB) and had a mass of 3 g while consuming 24 mW of power. These are the most sensitive broadband I-Q receivers at this frequency range that operate at room temperature, and are significantly lower in mass and power consumption than previously reported receivers.
20 citations
23 Jul 2010
TL;DR: An InGaAs/InAlAs/INP HEMT with sub-50nm EBL gate has been developed for sub-millimeter wave (SMMW) power amplifier (PA) applications as mentioned in this paper.
Abstract: An InGaAs/InAlAs/InP HEMT with sub-50nm EBL gate has been developed for sub-millimeter wave (SMMW) power amplifier (PA) applications. In this paper, we report the device performance including high drain current, high gain, high breakdown voltage and scalability to large gate periphery, which are essential for achieving high output power at these frequencies. Excellent yield, process uniformity and repeatability are also demonstrated, which is critical for power amplifiers employing large number of devices and gate fingers. 10mW output power is demonstrated from a fixtured 338 GHz PA module.
4 citations
23 Jul 2010
TL;DR: In this article, a 0.1-μm Pt-sunken gate InP HEMT low-noise amplifiers fabricated on 100 mm InP substrates were evaluated based on ΔS21 channel of 125 °C.
Abstract: Accelerated temperature lifetesting at T channel of 240, 255, and 270 °C was performed on 0.1-μm Pt-sunken InP HEMT low-noise amplifiers fabricated on 100 mm InP substrates. The reliability performance was evaluated based on ΔS21 channel of 125 °C. The high reliability demonstration of 0.1-μm Pt-sunken gate InP HEMT low-noise amplifiers on 100 mm InP substrates is essential for advanced military/space applications requiring high reliability performance.
3 citations
22 Jun 2010
TL;DR: In this article, the authors developed and demonstrated miniature 180 GHz Monolithic Microwave Integrated Circuit (MMIC) radiometer modules that have low noise temperature, low mass and low power consumption.
Abstract: We have developed and demonstrated miniature 180 GHz Monolithic Microwave Integrated Circuit (MMIC) radiometer modules that have low noise temperature, low mass and low power consumption. These modules will enable the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) of the Precipitation and All-weather Temperature and Humidity (PATH) Mission for atmospheric temperature and humidity profiling. The GeoSTAR instrument has an array of hundreds of receivers. Technology that was developed included Indium Phosphide (InP) MMIC Low Noise Amplifiers (LNAs) and second harmonic MMIC mixers and I-Q mixers, surface mount Multi-Chip Module (MCM) packages at 180 GHz, and interferometric array at 180 GHz. A complete MMIC chip set for the 180 GHz receiver modules (LNAs and I-Q Second harmonic mixer) was developed. The MMIC LNAs had more than 50% lower noise temperature (NT=300K) than previous state-of-art and MMIC I-Q mixers demonstrated low LO power (3 dBm). Two lots of MMIC wafers were processed with very high DC transconductance of up to 2800 mS/mm for the 35 nm gate length devices. Based on these MMICs a 180 GHz Multichip Module was developed that had a factor of 100 lower mass/volume (16x18x4.5 mm3, 3g) than previous generation 180 GHz receivers.
3 citations
02 May 2010
TL;DR: In this article, the reliability performance of 1-µm Pt-sunken gate InP HEMT MMICs on 4-inch InP substrates was evaluated under elevated temperature lifetesting.
Abstract: Reliability performance of 01-µm Pt-sunken gate InP HEMT MMICs on 4-inch InP substrates was evaluated under elevated temperature lifetesting The primary degradation mechanism was observed to be the progressive Schottky junction reaction with the Schottky barrier InAlAs and the InGaAs channel Despite the progressive Schottky junction reaction with the InAlAs and InGaAs materials, the lifetest at T ambient of 280 °C projects the median-time-to-failure exceeding 1×106 hours at T channel of 125 °C This result indicates that the promising initial reliability performance was achieved on Pt-sunken gate InP HEMT MMICs on 4-inch InP substrates
1 citations