K.L. Tan

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

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.<<ETX>>

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. >

High-gain W band pseudomorphic InGaAs power HEMTs

The authors have fabricated 0.1- mu m T-gate pseudomorphic (PM) InGaAs power high-electron-mobility transistors (HEMTs) with record power and gain performance at 94 GHz. Devices with 40- mu m gate peripheries achieved 10.6-mW output power with 7.3-dB gain and 14.3% power-added efficiency (PAE). Devices with 160- mu m gate peripheries achieved 62.7-mW output power with 4.0-dB gain and 13.2% PAE. The authors believe the superior performance of these devices is due to the combination of a short 0.1- mu m T-gate, high-quality material, optimized device profile, and the reduction in source inductance due to source vias.<<ETX>>

High-power V-band pseudomorphic InGaAs HEMT

The authors present the DC and RF power performance of planar-doped channel InGaAs high-electron-mobility transistors (HEMTs). The planar-doped channel (PDC) pseudomorphic GaAs HEMT with 400 mu m of gate width exhibited an output power of 184 mW, corresponding to 460 mW/mm, with 4.6-dB saturation gain and 25% power-added efficiency at 55 GHz. Although higher power density is possible, the authors have designed the device to operate at less than 500 mW/mm for thermal and reliability reasons. Devices with unit gate finger widths ranging from 30 to 50 mu m were fabricated and characterized, with no performance degradation observed from using the longer gate fingers.<<ETX>>

Millimeter-wave, cryogenically-coolable amplifiers using AlInAs/GaInAs/InP HEMTs

The cryogenic performance of AlInAs/GaInAs/InP 0.1- mu m high-electron-mobility transistors (HEMTs) is reported. Collapse-free DC operation is observed down to the ambient temperature of 18 K. The application of these devices to Q- and E-band low-noise, cryogenically coolable amplifiers is demonstrated. The measured noise temperature of 15 K (noise figure of 0.2 dB) for a multistage 40-45-GHz amplifier with 33 dB of gain at the ambient of 18 K is in close agreement with the prediction of a simple noise model. A very low power consumption per stage of less than 1 mW is recorded. The noise temperature of the E-band cryogenic amplifier is less than 47 K at 70 GHz, demonstrating that the performance of HEMT receivers is now competitive with that of SIS (superconductor-insulator-superconductor) receivers in the 3-mm wavelength atmospheric window.<<ETX>>

A W-band single-chip transceiver for FMCW radar

A monolithic microwave integrated circuit (MMIC) chip containing a W-band voltage controlled oscillator (VCO). transmit amplifiers, a receiver low noise amplifier and a mixer is discussed. It is used as the front-end of a homodyne FMCW radar for target range and range rate sensing applications. The 6.9-mm*3.6-mm monolithic chip was fabricated using 0.1- mu m pseudomorphic InGaAs-AlGaAs-GaAs HEMT process technology. The transmitter output power is more than 10 dBm for frequencies in the range 90-94 GHz, and maximum tuning bandwidth is 500 MHz for the VO. The receiver channel has 6-dB conversion gain when the output transmitting power is 10 dBm. A compete radar system has been tested based on the single-chip MMIC front-end. The calculated range and range rate are in good agreement with the measurement data.<<ETX>>

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. >

Highpower 0.15-mm V-band pseudomorphic InGaAs-AlGaAs-GaAs HEMT

The DC and RF power performance of double heterostructure pseudomorphic InGaAs-AlGaAs-GaAs HEMTs at V-band is reported. A 0.15-mm*400-mm device has demonstrated output power of 225 mW (0.55 W/mm) with 4.5-dB power gain and 25.4% power-added efficiency (PAE) at 60 GHz. A 0.15-mm*320-mm device demonstrated 31.1% PAE with 170-mW (0.53 W/mm) output power and 5.3-dB power gain. These data represent the highest reported combination of output power, power gain and power-added efficiency for a single device at V-band.<<ETX>>

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>>

Ultralow-noise W-band pseudomorphic InGaAs HEMT's

Low-noise planar doped pseudomorphic (PM) InGaAs high-electron-mobility transistors (HEMTs) with a gate length of 0.1 mu m for W-band operation are discussed. These devices feature a multiple-finger layout with air bridges interconnecting the sources to reduce gate resistance. The device exhibits a minimum noise figure of 2.5 dB with an associated gain of 4.7 dB at 92.5 GHz. This result demonstrates the feasibility of using PM InGaAs HEMTs for W-band low-noise receivers without the need for using lattice-matched InP HEMTs.<<ETX>>