A 177–183 GHz High-Power GaN-Based Frequency Doubler With Over 200 mW Output Power
Shixiong Liang, Xubo Song, Lisen Zhang, Yuanjie Lv, Yuangang Wang, Bihua Wei, Yanmin Guo, Guodong Gu, Bo Wang, Shujun Cai, Zhihong Feng
Abstract
A GaN Schottky barrier diode (SBD) on SiC for frequency doubler applications was fabricated with a N-/N+ GaN stack of 200 nm/1500 nm in thickness and 5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">17</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> /8 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">18</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> in doping densities, respectively. A cut-off frequency of 459 GHz at zero bias and reverse breakdown voltage of 15.4 V were obtained. A quartz glass circuit with flip-chip-mounted GaN SBDs was inserted between split-waveguide blocks to form a balanced frequency doubler. When driven with 2 W input power in pulsed mode, measured output power was 200-244 mW from 177-183 GHz with efficiency 9.5-11.8%.