A broadband Ka-band AlGaN/GaN on SiC high electron-mobility transistor monolithic-microwave integrated-circuit (MMIC) power amplifier was developed for millimeter-wave antenna applications. The 0.18-mum gate two-stage 50-Omega matched MMIC produces 13plusmn1 dB of gain from 26 to 36 GHz. At 35 GHz, the measured continuous wave (CW) saturated output power (Pout) was 4 W (5 W pulsed), indicating a CW power density of 3.3 W/mm (4.2 W/mm pulsed). The CW power-added efficiency was 23%. Across the band, the measured CW Pout was >2 W (2.5 W pulsed). While individual (or partially matched single stage) devices have been demonstrated with good output power, to the best of our knowledge, this is the first report of a 10-GHz-bandwidth Ka-band GaN MMIC with high output power and gain. A unique aspect of the design, contributing to the wide bandwidth, is the use of positive feedback in the first stage to increase the gain. RF power stress test and detailed investigation of the channel temperature effect are presented. A preliminary RF power stress test indicates a lifetime of 1000 h at 191 degC channel temperature, and elevated temperature operation indicates that Pout decreases by 0.013 dB/degC

AlGaN/GaN $Ka$ -Band 5-W MMIC Amplifier

AlGaN/GaN High Electron Mobility Transistors (HEMTs) were developed for X-band applications. The operating voltage and temperature dependence of output power characteristics in CW operating conditions were investigated. The developed AlGaN/GaN HEMT with combined two dies of 11.52 mm gate periphery exhibits output power of over 81.3W with a power added efficiency (PAE) of 34% under VDS=30V, CW operating condition at 9.5GHz, and a gain compression level of 3dB.

X-band AlGaN/GaN HEMT with over 80W Output Power

AlGaN/GaN high electron mobility transistors (HEMTs) were developed for Ku-band applications. The operating voltage characteristics in CW operating conditions were investigated. The developed AlGaN/GaN HEMT with combined two dies of 12 mm gate periphery exhibits output power of over 30 W with a power added efficiency (PAE) of 12% under VDS = 30 V, CW operating condition at 14.25 GHz, and a gain compression level of 3 dB.

Ku-band AlGaN/GaN HEMT with over 30W

A 3.5 watt, 35 GHz power amplifier MMIC has been developed. The amplifier exhibits high performance at low processing cost, through the use of a commercially available 6-inch, 0.15-μm pHEMT process with 100 μm thick substrate. The single-ended four stage amplifier MMIC has 22 dB of gain at 35 GHz, 3.5 watts saturated output power (35.5 dBm), and power added efficiency of more than 25%, within a chip size of 12.75 mm2. In terms of power density, this is 740 mW/mm, which is to the authors’ knowledge the best reported for fully matched GaAs pHEMT MMICs on 100-μm substrates at millimetre-wave frequencies.

35 dBm, 35 GHz power amplifier MMICs using 6-inch GaAs pHEMT commercial technology

This letter reports the excellent radio frequency output characteristics of AlGaN/GaN-on-Si power amplifier (PA) monolithic microwave integrated circuits (MMICs) operating at the Ka-band, employing a recessed metal–insulator–semiconductor (MIS) structure with SiN x /HfON dual dielectric layers. The fabricated 0.15- $\mu \text{m}$ AlGaN/GaN-on-Si high electron-mobility transistor (HEMT) exhibited a low OFF-state current and reduced current collapse in comparison with the conventional Schottky gate HEMT; therefore, an enhanced output power of the PA MMIC is achieved. The fabricated two-stage PA MMIC exhibited a continuous-wave output power of >29 dBm with a power-added efficiency (PAE) of 14.5% at the drain voltage of 20 V, at 26.5 GHz.

Ka-Band MMIC Using AlGaN/GaN-on-Si With Recessed High- ${k}$ Dual MIS Structure

A broadband Ka-band AlGaN/GaN on SiC HEMT power amplifier MMIC was developed for millimeter-wave antenna applications. The output stage is composed of a 1.2-mm-wide device with 0.18 mum gate length. The two-stage 50-ohm matched MMIC produces 13plusmn1 dB of gain from 26 GHz to 36 GHz. At 35 GHz, the measured CW saturated output power was 4 W, indicating a power density of 3.3 W/mm. The power added efficiency was 23%. Across the band, the measured CW output power was > 2 W. While individual (or partially matched single stage) devices have been demonstrated with good output power, to the best of our knowledge, this is the first report of a 10 GHz-bandwidth Ka-band GaN MMIC with high output power, gain, and return loss

B. Luo

Papers

4-Watt Ka-Band AlGaN/GaN Power Amplifier MMIC