Showing papers by "Richard Lai published in 1994"

0.10 /spl mu/m graded InGaAs channel InP HEMT with 305 GHz f/sub T/ and 340 GHz f/sub max/

Abstract: We report here 305 GHz f/sub T/, 340 GHz f/sub max/, and 1550 mS/mm extrinsic g/sub m/ from a 0.10 /spl mu/m In/sub x/Ga/sub 1-x/As/In/sub 0.62/Al/sub 0.48/As/InP HEMT with x graded from 0.60 to 0.80. This device has the highest f/sub T/ yet reported for a 0.10 /spl mu/m gate length and the highest combination of f/sub T/ and f/sub max/ reported for any three-terminal device. This performance is achieved by using a graded-channel design which simultaneously increases the effective indium composition of the channel while optimizing channel thickness. >

Novel monolithic multifunctional balanced switching low-noise amplifiers

Abstract: A novel multifunctional balanced switching low-noise amplifier (BSLNA) which can be used as a low-noise amplifier, a low-noise switch, or a broad-band 180/spl deg/ phase shifter is proposed. Two monolithic BSLNA's at Ka- and W-band frequencies are demonstrated using the 0.1 /spl mu/m pseudomorphic (PM) InP- and GaAs-based HEMT technologies, respectively. Potential applications of the novel BSLNA are in on-off keying (OFK) or binary phase-shift keying (BPSK) in communication systems and input switch for Dicke-switched radiometer systems. The extensions of this BSLNA structure to be a single-pole double-throw switch and a crossbar switch to interchange two signal paths are also addressed. >

A high efficiency V-band monolithic HEMT power amplifier

Abstract: We report the performance of a monolithic V-band power amplifier using 0.15-/spl mu/m double heterostructure pseudomorphic InGaAs/AlGaAs/GaAs HEMT's. The amplifier using a 400-/spl mu/m device driving a 2/spl times/400-/spl mu/m device. It has demonstrated output power of 313 mW (0.39 W/mm) with 8.95 dB power gain and 19.9% PAE at 59.5 GHz. These data represent the highest reported combination of output power, power gain, and power-added efficiency reported for a V-band monolithic power amplifier. >

A monolithically integrated 120-GHz InGaAs/InAlAs/InP HEMT amplifier

Abstract: We report the design and gain performance for a two-stage 120-GHz monolithically integrated amplifier using 0.1-/spl mu/m gate length pseudomorphic In/sub 0.60/Ga/sub 0.40/As/In/sub 0.52/Al/sub 0.48/As/InP HEMT's. The two-stage amplifier demonstrated 10-12 dB gain measured between 119.5 to 123.5 GHz. To the best of our knowledge, this is the first demonstration of a monolithically integrated InP HEMT amplifier reported at D-band. >

A V-band high-efficiency pseudomorphic HEMT monolithic power amplifier

Abstract: This paper presents a high-power and high-efficiency monolithic power amplifier at V-band utilizing highly reliable and manufacturable 0.15 /spl mu/m InGaAs-AlGaAs-GaAs pseudomorphic HEMT fabrication technology. The performance of the power amplifier is 13.8 dB small signal gain, 13.9% power-added efficiency, and 26.83 dBm (482 mW) compressed power output at 60 GHz for unpassivated HEMT process. The same circuit with passivated process produced a linear gain of 13.2 dB, 11% power-added efficiency, and compressed output power of 25.68 dBm (370 mW). The producibility of this amplifier has been demonstrated in volume production with several wafer lots resulting in a 20% total yield through RF tests. >

A 0.1 /spl mu/m W-band HEMT production process for high yield and high performance low noise and power MMICs

Abstract: We have developed a W-band HEMT MMIC process which has demonstrated reproducible high performance for both low noise and power amplifier designs. This paper presents the details of the fabrication process as well as device and circuit results from 69 wafers. Three-stage LNAs have demonstrated noise figure as low as 4.4 dB with gains as high as 27 dB from 92 to 96 GHz. The LNA RF lot yield was as high as 78%. The same process has demonstrated power amplifiers with output power of 19 dBm at 94 GHz, with RF yield of 37%.

A novel W-band monolithic push-pull power amplifier

Abstract: A monolithic W-band push-pull two-stage power amplifier has been developed using 0.1 pm AlGaAs-InGaAs-GaAs pseudomorphic T-gate power HEMT technology. This novel design utilizes the push-pull scheme to take the advantage of a virtual ground in a push-pull HEMT device pair which eliminates the via hole inductance, and improves the power amplifier performance at millimeter-wave frequency. The measurement results show that a small signal gain of 12 dB, an output power of 19.4 dBm, and a power added efficiency of 13.3% have been achieved at 90 GHz, and presents state-of-the-art performance for a monolithic power amplifiers at this frequency. To our knowledge, this is the first reported monolithic push-pull amplifier at millimeter-wave frequencies.

Monolithic regulated self-biased HEMT MMIC's

Abstract: This work benchmarks the first demonstration of a monolithic HEMT IC design which incorporates active regulated self-bias. The HEMT current regulator design consists of integrating an op-amp in a feedback configuration with the LNA to achieve gain, noise figure, and DC bias performance which is tolerant to threshold variations due to the HEMT process. The HEMT LNA bias current can be maintained to within /spl plusmn/3% variation over a process threshold variation (V,,) of /spl plusmn/0.5 V. The bias circuitry regulates the bias current to within 1.5% over a 100/spl deg/C temperature range. The amplifier has a nominal gain of 10 dB and a noise figure of 2.5 dB over a 1-10 GHz bandwidth. Across several wafers with a threshold voltage spread of 0.5 V, the regulated LNA maintains repeatable gain and noise figure which varies by less than 1 and 0.75 dB, respectively. The monolithic regulated self-bias technique can be integrated with other HEMT MMIC's in order to improve the performance and reliability, as well as to reduce the cost and weight of Integrated Microwave Assemblies (IMA's). >

An ultra-low noise cryogenic Ka-Band InGaAs/InAlAs/InP HEMT front-end receiver

Abstract: We present here the design and performance of a 4-stage Ka-band cryogenic amplifier using a front-end 0.1-/spl mu/m gate length InP HEMT. The amplifier demonstrated 20-25 K uncorrected noise temperature (/spl sim/0.3-dB noise figure) from 31-33 GHz with 30-33 dB associated gain at 12 K ambient temperature. To date, this is the best reported HEMT cryogenic amplifier performance at this frequency band and is a factor of two improvement in noise temperature compared to previous designs. >

A high power and high efficiency monolithic power amplifier at V-band using pseudomorphic HEMTs

Abstract: This paper presents a high power and high efficiency monolithic power amplifier at V-band utilizing highly reliable and manufacturable 0.15 /spl mu/m InGaAs/AlGaAs/GaAs pseudomorphic HEMT fabrication technology. The performance of the power amplifier is 13.83 dB small signal gain, 13.9% power-added-efficiency, and 26.83 dBm (482 mW) at 60 GHz for unpassivated HEMT process. The same circuit with passivated process produced a linear gain of 13.18 dB, 11% power-added-efficiency, and compressed output power of 25.68 dBm (370 mW). The producibility of this amplifier has been demonstrated in volume production with several wafer lots resulting in a 20% total yield through RF tests. >

Millimeter-wave high power amplifiers using pseudomorphic HEMTs

Abstract: Millimeter wave high power amplifier modules operating at V-band have been developed utilizing monolithic amplifiers as building blocks. The two stage amplifiers used in this module provide better that 370 mW output power with compressed gain of 7 dB and greater that 11% power-added-efficiency over the frequency range of 59.5 to 63.5 GHz. These high yielding amplifier utilize 0.15 /spl mu/m passivated T-gate pseudomorphic HEMT fabrication technology. With low loss planar combiners, these modules produced an output power of 740 mW with a power gain of 11.68 dB. These state-of-the-art results represent the highest output power and power gain reported using monolithic amplifiers as building blocks. >

On-wafer calibration techniques and applications at V-band

Abstract: There is considerable interest in HEMT MMIC applications operating at V-band and higher frequencies due to their low noise, high power, and high power efficiency capability. A quantitative investigation of calibration methods have been performed to study the effect of calibration techniques on V-band device measurements and model development. This work compares SOLT, LRM, and multi-line TRL calibrations relative to each other. The analysis is then applied to pseudomorphic InGaAs HEMT devices to provide useful information on the effect of calibration on small signal-intrinsic parameter extraction at V-band. >

A monolithic HEMT regulated self-biased LNA

Abstract: This work benchmarks the first demonstration of a monolithic HEMT LNA design which incorporates active regulated self-bias. The HEMT LNA bias current can be maintained to within /spl plusmn/3% variation over a process threshold variation (Vgs) of /spl plusmn/0.5 Volt. The bias circuitry regulates the bias current to within 1.5% over a 100/spl deg/C temperature range. The amplifier has a nominal gain of 10 dB and a noise figure of 2.5 dB over a 1-10 GHz bandwidth. Across several wafers with a threshold voltage spread of 0.5 Volts, the active bias-regulated LNA maintains repeatable gain and noise figure which varies by less than 1 dB and 0.75 dB respectively. This monolithic regulated self-biased LNA demonstration sheds new light on the producibility and reliability of HEMT MMICs and their applications. >

A novel compact monolithic active regulated self-biased InP HEMT amplifier

Abstract: This letter reports on the first results of a monolithic active regulated self-biased HEMT amplifier fabricated in InP technology. The self-bias scheme incorporates an op-amp-based HEMT regulator topology that regulates the bias current to within 6% over a threshold variation of /spl plusmn/0.2 V. The DC yield based on this performance criteria was 75% across a wafer. The InP HEMT amplifier achieves an RF gain of 10-dB and a 3-dB bandwidth of 1-14 GHz. Across a wafer with a total threshold variation of 0.4 V, the gain variation was maintained to less than /spl plusmn/1 db. The compact integrated HEMT regulated amplifier circuit was realized using area-efficient analog design techniques that consumed less than 1.3/spl times/1.1 mm/sup 2/. This demonstration has far-reaching implications to the producibility and reliability of InP HEMT MMIC's. >

Enhanced cryogenic on-wafer techniques for accurate In/sub x/Ga/sub 1-x/As HEMT device models

Abstract: An accurate on-wafer cryogenic measurement system is presented for empirical millimeter-wave device studies of In/sub x/Ga/sub 1-x/As HEMTs. Multi-line TRL calibrations are performed to provide traceable baseline results for cryogenic S-parameter measurements. This technique is then applied to develop wide frequency band small-signal models for HEMTs with In channel composition varied from 22% to 70%. >

A V-band high-efficiency pseudomorphic HEMT monolithic power amplifier

Abstract: This paper presents a high-power and high-efficiency monolithic power amplifier at V-band utilizing highly reliable and manufacturable 0.15 μm InGaAs/AlGaAs/GaAs pseudomorphic HEMT fabrication technology. The performance of the power amplifier is 13.8 dB small signal gain, 13.9% power-added efficiency, and 26.83 dBm (482 mW) compressed power output at 60 GHz for unpassivated HEMT process. The same circuit with passivated process produced a linear gain of 13.2 dB, 11% power-added efficiency, and compressed output power of 25.68 dBm (370 mW). The producibility of this amplifier has been demonstrated in volume production with several wafer lots resulting in a 20% total yield through RF tests

Novel monolithic multifunctional balanced switching low-noise amplifiers

Abstract: A novel multifunctional balanced switching low-noise amplifier (BSLNA) which can be used as a low-noise amplifier, a low-noise switch, or a broad-band 180° phase shifter is proposed. Two monolithic BSLNA's at Ka- and W-band frequencies are demonstrated using the 0.1 μm pseudomorphic (PM) InP- and GaAs-based HEMT technologies, respectively. Potential applications of the novel BSLNA are in on-off keying (OFK) or binary phase-shift keying (BPSK) in communication systems and input switch for Dicke-switched radiometer systems. The extensions of this BSLNA structure to be a single-pole double-throw switch and a crossbar switch to interchange two signal paths are also addressed