T.H. Chen

High-performance in W-band monolithic pseudomorphic InGaAs HEMT LNA's and design/analysis methodology

High-performance W-band monolithic one- and two-stage low noise amplifiers (LNAs) based on pseudomorphic InGaAs-GaAs HEMT devices have been developed. The one-stage amplifier has a measured noise figure of 5.1 dB with an associated gain of 7 dB from 92 to 95 GHz, and the two-stage amplifier has a measured small signal gain of 13.3 dB at 94 GHz and 17 dB at 89 GHz with a noise figure of 5.5 dB from 91 to 95 GHz. An eight-stage LNA built by cascading four of these monolithic two-stage LNA chips demonstrates 49 dB gain and 6.5 dB noise figure at 94 GHz. A rigorous analysis procedure was incorporated in the design, including accurate active device modeling and full-wave EM analysis of passive structures. The first pass success of these LNA chip designs indicates the importance of a rigorous design/analysis methodology in millimeter-wave monolithic IC development. >

Broadband monolithic passive baluns and monolithic double-balanced mixer

The design and fabrication of four broadband monolithic passive baluns including CPW Marchand, multilayer MS Marchand, planar-transformer and broadside-coupled line baluns are presented. Operational frequencies range from 1.5 GHz to 24 GHz. Maximum relative bandwidths in excess of 3:1 are achieved. Simulated performances using full wave electromagnetic analysis are shown to agree with the measured results. Two accurate equivalent circuit models constructed from either electromagnetic simulated or measured S-parameters are developed for the MS Marchand and transformer baluns making the optimization of baluns and circuit design using the baluns much more efficient. The design of monolithic double-balanced diode mixer using two planar-transformer baluns is also presented. Without DC bias, the mixer shows a minimum conversion loss of 6 dB with the RF at 5 GHz and a LO drive of 15 dBm at 4 GHz. The measured input IP/sub 3/ of this mixer is better than 15 dBm over the 4 to 5.75 GHz frequency band. >

A W-band monolithic downconverter

The design, fabrication, and evaluation of a fully integrated W-band monolithic downconverter based on InGaAs pseudomorphic HEMT technology are presented. The monolithic downconverter consists of a two-stage low-noise amplifier and a single-balanced mixer. The single-balanced mixer has been designed using the HEMT gate Schottky diodes inherent to the process. Measured results of the complete downconverter show conversion gain of 5.5 dB and a double-sideband noise figure of 6.7 dB at 94 GHz. Also presented is the downconverter performance characterized over the -35 degrees C to +65 degrees C temperature range. The downconverter design was a first pass success and has a high circuit yield. >

A 0.1-W W-band pseudomorphic HEMT MMIC power amplifier

The authors have designed and fabricated monolithic power amplifiers using pseudomorphic InGaAs power HEMTs (high-electron-mobility transistors) with record power and gain performance at W-band frequency. The two-stage amplifier has a small-signal gain of 9 dB and can deliver 0.1-W output power with 5.9-dB associated gain and 6.6% power-added efficiency at 93.5 GHz. The successful first pass design of the W-band MMIC (monolithic microwave integrated circuit) power amplifier is due to the superior device performance and the millimeter-wave monolithic power amplifier design techniques.<<ETX>>

An ultra low noise W-band monolithic three-stage amplifier using 0.1- mu m pseudomorphic InGaAs/GaAs HEMT technology

An ultra-low-noise W-band monolithic three-stage amplifier based on 0.1- mu m pseudomorphic InGaAs/GaAs high electron mobility transistor (HEMT) devices has been developed. This amplifier has a measured noise figure of 3.5 dB with an associated small signal gain of 21 dB at 94 GHz. This is the best reported performance of a monolithic W-band high-gain low-noise amplifier (LNA), significantly improved compared with previous records in terms of noise figure and associated gain. Accurate modeling techniques were essential to the success of this monolithic circuit design, which included active device and full-wave electromagnetic analysis of passive matching structures. The measured results of the W-band three-stage monolithic microwave integrated circuit (MMIC) LNA from 91 to 97 GHz are presented.<<ETX>>

A monolithic W-band three-stage LNA using 0.1 mu m InAlAs/InGaAs/InP HEMT technology

A monolithic W-band three-stage low-noise amplifier (LNA) based on 0.1- mu m pseudomorphic (PM) InAlAs/InGaAs/InP high-electron-mobility transistors (HEMTs) has been developed. This LNA has demonstrated a noise figure of 4.3 dB and an associated small-signal gain of 19 dB at 100 GHz with a low DC power consumption of 20 mW. This demonstrates the potential of InP HEMT technology for higher millimeter-wave applications. The gain and noise performance is comparable with the best reported results of the monolithic W-band LNA using GaAs-based PM HEMTs even at this first iteration phase of the development. The HEMTs discussed consume only 30% of the DC power typically needed in the GaAs-based HEMT LNAs with the same device periphery and design approach.<<ETX>>

Broadband single- and double-balanced resistive HEMT monolithic mixers

A double-balanced (DB) 3-18 GHz and a single-balanced (SB) 2-16 GHz resistive HEMT monolithic mixer have been successfully developed. The DB mixer consists of a AlGaAs/InGaAs HEMT quad, an active LO balun, and two passive baluns for RF and IF. At 16 dBm LO power, this mixer achieves the conversion losses of 7.5-9 dB for 4-13 GHz RF and 7.5-11 dB for 3-18 GHz RF. The SB mixer consists of a pair of AlGaAs/InGaAs HEMTs, an active LO balun, a passive IF balun and a passive RF power divider. At 16 dBm LO power, this mixer achieves the conversion losses of 8-10 dB for 4-15 GHz RF and 8-11 dB for 2-16 GHz RF. The simulated conversion losses of both mixers are very much in agreement with the measured results. Also, the DB mixer achieves a third-order input intercept (IP/sub 3/) of +19.5 to +27.5 dBm for a 7-18 GHz RF and 1 GHz IF at a LO drive of 16 dBm while the SB mixer achieves an input IP/sub 3/ of +20 to +28.5 dBm for 2 to 16 GHz RF and 1 GHz IF at a 16 dBm LO power. The bandwidth of the RF and LO frequencies are approximately 6:1 for the DB mixer and 8:1 for the SB mixer. The DB mixer of this work is believed to be the first reported DB resistive HEMT MMIC mixer covering such a broad bandwidth. >

A W-band image-rejection downconverter

The design, fabrication, and evaluation of a W-band image-rejection downconverter based on pseudomorphic InGaAs-GaAs HEMT technology are presented. The image-rejection downconverter consists of a monolithic three-stage low-noise amplifier, a monolithic image-rejection mixer, and a hybrid IF 90 degrees coupler with an IF amplifier. The three-stage amplifier has a measured noise figure of 3.5 dB, with an associated small signal gain of 21 dB at 94 GHz while the image-rejection mixer has a measured conversion loss of 11 dB with +10 dBm LO drive at 94.15 GHz. Measured results of the complete image-rejection downconverter including the hybrid IF 90 degrees coupler and a 10 dB gain amplifier show a conversion gain of more than 18 dB and a noise figure of 4.6 dB at 94.45 GHz. >

A W-band monolithic InGaAs/GaAs HEMT Schottky diode image reject mixer

A W-band monolithic image reject mixer (IRM) utilizing pseudomorphic InGaAs/GaAs high-electron-mobility transistor (HEMT) diodes has been developed. The monolithic circuit integrates two single-balanced HEMT Schottky diode mixers, a W-band Lange coupler, and a Wilkinson power divider on one chip. The image reject mixer including an external hybrid IF 90 degrees coupler has a measured conversion loss of less than 11 dB and a 12-16-dB rejection with 10-dBm local oscillator (LO) drive at 94.15 GHz. The success of this monolithic IRM development is attributed to the excellent device performance, the simple circuit topology, and a rigorous design/analysis methodology.<<ETX>>

High performance resistive EHF mixers using InGaAs HEMTs

The design, fabrication, and testing of a hybrid and a monolithic single-balanced EHF mixer are presented. Very low mixer intermodulation distortion was achieved using a 0.2- mu m*160- mu m pseudomorphic InGaAs high-electron-mobility transistor (HEMT) biased in the resistive mode. Both mixers show similar excellent measured performance. Mixer conversion loss over the 26-29 GHz RF frequency band is about 7-9 dB for DC to 2 GHz IF (intermediate frequency) frequencies. With an LO (local oscillator) power of +13 dBm, the measured input two-tone third-order intercept point is higher than +24 dBm.<<ETX>>