Ming-Yih Kao

A Wideband Power Amplifier MMIC Utilizing GaN on SiC HEMT Technology

The design and performance of a wideband power amplifier MMIC suitable for electronic warfare (EW) systems and other wide bandwidth applications is presented. The amplifier utilizes dual field plate 0.25-mum GaN on SiC device technology integrated into the three metal interconnect (3MI) process flow. Experimental results for the MMIC at 30V power supply operation demonstrate greater than 10 dB of small signal gain, 9 W to 15 W saturated output power and 20% to 38% peak power added efficiency over a 1.5 GHz to 17 GHz bandwidth.

High efficiency Ka-band Gallium Nitride power amplifier MMICs

The design and performance of two high efficiency Ka-band power amplifier MMICs utilizing a 0.15μm GaN HEMT process technology is presented. Measured in-fixture continuous wave (CW) results for the 3-stage balanced amplifier demonstrates up to 11W of output power and 30% power added efficiency (PAE) at 30GHz. The 3-stage single-ended design produced over 6W of output power and up to 34% PAE. The die size for the balanced and single-ended MMICs are 3.24×3.60mm2 and 1.74×3.24mm2 respectively.

High-performance double-recessed enhancement-mode metamorphic HEMTs on 4-in GaAs substrates

Enhancement-mode InAlAs/InGaAs/GaAs metamorphic HEMTs with a composite InGaAs channel and double-recessed 0.15-/spl mu/m gate length are presented. Epilayers with a room-temperature mobility of 10 000 cm/sup 2//V-s and a sheet charge of 3.5/spl times/10/sup 12/cm/sup -2/ are grown using molecular beam epitaxy on 4-in GaAs substrates. Fully selective double-recess and buried Pt-gate processes are employed to realize uniform and true enhancement-mode operation. Excellent dc and RF characteristics are achieved with threshold voltage, maximum drain current, extrinsic transconductance, and cutoff frequency of 0.3 V, 500 mA/mm, 850 mS/mm, and 128 GHz, respectively, as measured on 100-/spl mu/m gate width devices. The load pull measurements of 300-/spl mu/m gate width devices at 35 GHz yielded a 1-dB compression point output power density of 580 mW/mm, gain of 7.2 dB, and a power-added efficiency of 44% at 5 V of drain bias.

GaN Takes the Lead

Gallium nitride (GaN) technology is transforming RF monolithic microwave integrated circuits (MMICs) for power amplifiers (PAs), switches, low noise amplifiers, and more. Vendors are now producing GaN MMICs in volume and achieving outstanding performance. GaNs characteristics enable PA MMICs with 35 times the output power of GaAs alternatives or much smaller die sizes from L-band through Ka-band. High-power switches with low insertion loss up through 18 GHz have been developed. Low-noise amplifiers have been demonstrated with noise figures equivalent to gallium arsenide (GaAs) but with much higher input power survivability. The market for GaN RF MMICs spans commercial and military applications, including base station, cable television infrastructure, communications, radar and electronic warfare (EW), among others.

A GaAs MHEMT distributed amplifier with 300-GHz gain-bandwidth product for 40-Gb/s optical applications

A distributed amplifier with greater than 13.4 dB gain and 65 GHz bandwidth has been demonstrated using 0.15 /spl mu/m metamorphic GaAs HEMT technology. The amplifier has an average noise figure of 3.1 dB from 2-40 GHz and an output 1-dB compression point of 11 dBm at 22 GHz. The group delay variation from 1 to 40 GHz is /spl plusmn/7.5 ps. The amplifier may be biased with a single supply voltage, and consumes only 105 mW. With these characteristics, the amplifier is ideally suited for 40-Gb/s optical networks.

A K-Band 5W Doherty Amplifier MMIC Utilizing 0.15µm GaN on SiC HEMT Technology

The design and performance of a K-Band Doherty amplifier MMIC is presented. The monolithic 2-stage amplifier was fabricated with a dual field plate 0.15um GaN on SiC HEMT process technology. Measured continuous wave results at 23GHz demonstrate over 5W of saturated output power and up to 48% power added efficiency. Peak efficiency occurs at approximately 1dB of gain compression and the amplifier maintains 25% power added efficiency at 8dB of input power back off from P1dB.

X-band GaAs mHEMT LNAs with 0.5 dB noise figure

Two X-band LNA ICs have been demonstrated using a 0.15 /spl mu/m metamorphic GaAs HEMT technology. The amplifiers have an average noise figure of 0.5 dB and power gain greater than 31 dB from 7-10 GHz. A current-shared version had gain flatness better than 1 dB, return losses greater than 11 dB, and power consumption of 42 mW. A high linearity version has an output third-order intercept point greater than 20.5 dBm from 6-12 GHz.

High efficiency Ka-band power amplifier MMICs fabricated with a 0.15µm GaN on SiC HEMT process

The design and performance of two high efficiency Ka-band power amplifier MMICs utilizing a 0.15µm GaN HEMT process technology is presented. Measured in-fixture continuous wave (CW) results for the 3-stage amplifiers demonstrates 8–9W of output power for the balanced MMIC and 4.5–6W for the single-ended configuration. The associated power added (PAE) efficiency of both amplifiers exceeds 25% at Ka-band. The die sizes for the balanced and single-ended MMICs are 2.55×3.80mm² and 1.39×3.42mm² respectively.

AlGaN/GaN HEMTs with PAE of 53% at 35 GHz for HPA and Multi-Function MMIC Applications

We would like to report on AlGaN/GaN HEMTs on SiC substrate with stat-of the-art power performance at Ka-band. Power gains of 5.6, 6.3 and 6.7 dB and peak PAE of 53, 53 and 51% were measured at 35 GHz when 200-mum GaN HEMTs were biased at 10, 15 and 20 volts, respectively. At 10 GHz, 400-mum GaN HEMTs exhibited maximum PAE of 67%, power gain of 11.3 dB and power density of 5.6 W/mm when devices were biased at 30 volts. Furthermore, we have also achieved 36 to 38.7 ilBm TOI at a wide range of 10 to 26 dBm total output power for a 400-mum GaN HEMT. Very low noise figures of 1.4 dB at 26 GHz were measured on 100, 200 and 300-mum wide GaN HEMTs as well. In this work, we have demonstrated that GaN HEMTs on SiC substrate is a much superior device technology to GaAs-based pHEMT for microwave applications up through Ka-band.

A high power Q-band MMIC power amplifier based on dual-recess 0.15 /spl mu/m pHEMT

This paper demonstrates a three stage Q-band power amplifier based on TriQuints three metal interconnect (3MI) technology and 0.15/spl mu/m dual-recess GaAs pHEMT process. The design, fabrication and experimental results of the MMIC amplifier are discussed. The amplifier employed a balanced configuration to achieve higher output power and good return loss. Each half consisted of three amplification stages with a 1:2:2 drive ratio and 12.8 mm of total FET periphery. Utilizing dual recess pHEMT technology the amplifier can be biased at Vds = 6V with 2A quiescent current; an equivalent of 150mA/mm current density. The amplifier can deliver 34 dBm of output power over a 41-46 GHz bandwidth with 15dB gain and typically -15dB return loss. The chip dimensions are 3.4 mm /spl times/ 4.2 mm. Due to the high-integration level, this Q-band MMIC amplifier enables low cost millimeter-wave RF equipment for potential point to point radio communications and military applications.