A Yield-Improvement Method for Millimeter-Wave GaN MMIC Power Amplifier Design Based on Load—Pull Analysis
Shuman Mao, Wei Zhang, Yuan Yao, Xuming Yu, Hongqi Tao, Fangjin Guo, Chunjiang Ren, Tangsheng Chen, Bin Zhang, Ruimin Xu, Bo Yan, Yuehang Xu
Abstract
Process fluctuations can significantly affect the yield of millimeter-wave circuits based on submicrometer semiconductor processes. A yield-improvement design that incorporates passive circuits is well established. However, how to consider the process fluctuation in active circuit designs (e.g., power amplifiers) and improve yield is still a challenge. In this article, a yield-improvement load-pull design method, which can be used to find optimum load impedance accounting for high yield while maintaining good output performance, is presented. The yield-improvement load-pull theory is described using an analytical model of transistor large-signal performance considering the process fluctuation. A method of the yield-improvement load-pull for the practical microwave monolithic integrated circuit (MMIC) design is introduced in detail. For demonstration purposes, a high-performance Ka-band power amplifier MMIC is designed. The results show that with the proposed yield-improvement load-pull method, an obvious improvement of yield can be observed with only minimal sacrifice of the output power ( P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">out</sub> ) and the power added efficiency ( η <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PAE</sub> ), respectively. As a result, the method of this article can be used to improve the yield of millimeter-wave/terahertz integrated circuits (ICs).