HEMT Monolithic Microwave Integrated Circuit Research Articles

Reliability investigation of 0.07-μm InGaAs-InAlAs-InP HEMT MMICs with pseudomorphic In0.75Ga0.25As channel

The authors have investigated the reliability performance of G-band (183 GHz) monolithic microwave integrated circuit (MMIC) amplifiers fabricated using 0.07-/spl mu/m T-gate InGaAs-InAlAs-InP HEMTs with pseudomorphic In/sub 0.75/Ga/sub 0.25/As channel on 3-in wafers. Life test was performed at two temperatures (T/sub 1/ = 200 /spl deg/C and T/sub 2/ = 215 /spl deg/C), and the amplifiers were stressed at V/sub ds/ of 1 V and I/sub ds/ of 250 mA/mm in a N/sub 2/ ambient. The activation energy is as high as 1.7 eV, achieving a projected median-time-to-failure (MTTF) /spl ap/ 2 /spl times/ 10/sup 6/ h at a junction temperature of 125 /spl deg/C. MTTF was determined by 2-temperature constant current stress using /spl Delta/G/sub mp/ = -20% as the failure criteria. The difference of reliability performance between 0.07-/spl mu/m InGaAs-InAlAs-InP HEMT MMICs with pseudomorphic In/sub 0.75/Ga/sub 0.25/As channel and 0.1-/spl mu/m InGaAs-InAlAs-InP HEMT MMICs with In/sub 0.6/Ga/sub 0.4/As channel is also discussed. The achieved high-reliability result demonstrates a robust 0.07-/spl mu/m pseudomorphic InGaAs-InAlAs-InP HEMT MMICs production technology for G-band applications.

High-power broad-band AlGaN/GaN HEMT MMICs on SiC substrates

Broad-band high-power cascode AlGaN/GaN high electron-mobility transistor monolithic-microwave integrated-circuit (MMIC) amplifiers with high gain and power-added efficiency (PAE) have been fabricated on high-thermal conductivity SiC substrates. A cascode gain cell exhibiting 5 W of power at 8 GHz with a small-signal gain of 19 dB was realized. A nonuniform distributed amplifier (NDA) based on this process was designed, fabricated, and tested, yielding a saturated output power of 3-6 W over a dc-8-GHz bandwidth with an associated PAE of 13%-31%. A broad-band amplifier MMIC using cascode cells in conjunction with a lossy-match input matching network showed a useful operating range of dc-8 GHz with an output power of 5-7.5 W and a PAE of 20%-33.% over this range. The third-order intermodulation products of the amplifiers under two-tone excitation were studied and third-order-intercept values of 42 and 43 dBm (computed using two-tone carrier power) for the lossy match and NDA amplifiers were obtained.

A 180-GHz monolithic sub-harmonic InP-based HEMT diode mixer

A 180-GHz monolithic sub-harmonic diode mixer is developed using 0.08-μm pseudomorphic InAlAs-InGaAs HEMT MMIC process on a 2-mil-thick InP substrate. This mixer demonstrates a conversion loss of better than 16.5 dB from 175 to 182 GHz with an LO drive of 13 dBm at 96 GHz. This is the first demonstration of a monolithic subharmonic HEMT diode mixer in this frequency range. The design and measurement of this monolithic microwave integrated circuit (MMIC) mixer and the waveguide-to-microstrip line transitions of the test-fixture are presented.

An InP HEMT MMIC LNA with 7.2-dB gain at 190 GHz

We present the highest frequency performance of any solid-state monolithic microwave integrated circuit (MMIC) amplifier. A 2-stage 80-nm gate length InGaAs/InAlAs/InP HEMT MMIC balanced amplifier has a measured on-wafer peak gain of 7.2 dB at 190 GHz and greater than 5 dB gain from 170 to 194 GHz. The circuit was fabricated using a pseudomorphic 20-nm In/sub 0.65/Ga/sub 0.35/As channel HEMT structure grown on a 3-in InP substrate by MBE. Based on the measured circuit results, the intrinsic exhibits an F/sub max/ greater than 400 GHz.

A 95-GHz InP HEMT MMIC amplifier with 427-mW power output

We have established a state-of-the-art InGaAs-InAlAs-InP HEMT MMIC fabrication process for millimeter-wave high-power applications. A two-stage monolithic microwave integrated circuit (MMIC) power amplifier with 0.15-/spl mu/m gate length and 1.28-mm output periphery fabricated using this process has demonstrated an output power of 427 mW with 19% power-added efficiency at 95 GHz. To our knowledge, this is the highest output power ever reported at this frequency for any solid-state MMIC amplifier.

A GaAs HEMT MMIC chip set for automotive radar systems fabricated by optical stepper lithography

A 77 GHz automotive radar system for collision avoidance and intelligent cruise control has recently gained interest because of its huge market potential. The questions of the optimum technological and system approaches leading to both low cost and high performance have not yet been finally answered. The approach to this problem reported here differs mainly in two aspects from the GaAs monolithic microwave integrated circuit (MMIC) solutions described earlier: (1) 0.12 /spl mu/m gatelength pseudomorphic high electron mobility transistors (PHEMTs) are fabricated by optical stepper lithography, (2) a coplanar design is used. A fully passivated PHEMT MMIC fabrication process is reported with current-gain and power-gain cutoff frequencies exceeding 115 and 220 GHz, respectively. The design and performance of a chip set consisting of four different MMICs [voltage controlled oscillator (VCO), harmonic mixer, transmitter, receiver] are described. The great potential of this MMIC approach to meet all system requirements of an automotive radar sensor in a cost-effective and production-oriented way is shown. To our knowledge, this is the first demonstration of W-band coplanar multifunctional MMICs fabricated by optical stepper lithography.

A 94-GHz 130-mW InGaAs/InAlAs/InP HEMT high-power MMIC amplifier

We have developed W-band high-power monolithic microwave integrated circuit (MMIC) amplifiers using passivated 0.15 μm gate length InGaAs/InAlAs/InP HEMT's. A 640 μm single-stage MMIC amplifier demonstrated an output power of 130 mW with 13% power-added efficiency and 4 dB associated gain at 94 GHz. This result represents the best output power to date measured from a single fixtured InP-based HEMT MMIC at this frequency.

High-yield W-band monolithic HEMT low-noise amplifier and image rejection downconverter chips

High-yield W-band monolithic microwave integrated circuits (MMICs), namely, a three-stage low-noise amplifier (LNA) and a monolithic image rejection downconverter (IRD), are discussed. The LNA is used as the front end followed by an image rejection mixer (IRM). These MMICs were fabricated in the 0.1- mu m AlGaAs-InGaAs-GaAs HEMT production line. The LNA demonstrated a typical 17-dB gain and 4.5-5.5-dB noise figure at 94 GHz. The complete monolithic IRD has a measured conversion gain of 7-9 dB with a single-side-band noise figure of 6 dB when downconverting a 93-95-GHz RF signal to 50-500 MHz. The downconversion requires an LO power of 9 dBm. The development of these MMICs shows the increasing maturity of GaAs-based HEMT MMIC technology at W-band. >

A novel Ku-Band low noise amplifier with hemt and GaAs MMIC

A novel Ku-band low noise amplifier with a high electron mobility transistor (HEMT) and a GaAs monolithic microwave integrated circuit (MMIC) has been demonstrated. Its noise figure is less than 1.9dB with an associated gain larger than 27dB and an input/output VSWR less than 1.4 in the frequency range of 11.7–12.2GHz. The HEMT and the microwave series inductance feedback technique are used in the first stage of the amplifier, and a Ku-band MMIC is employed in the last stage. The key to this design is to achieve an optimum noise match and a minimum input VSWR matching simultaneously by using the microwave series inductance feedback method. The BJ-120 waveguides are used in both input and output of the amplifier.