Xiao, O. Chi, Y.L. Gan, N. Ma, X. Zhou, Z.S. JACoW Publishing Geneva, Switzerland 2226-0366 978-3-95450-194-6 10.18429/JACoW-LINAC2018-THPO103 English 914-916 THPO103 cavity power-supply controls MMI LLRF Contribution to a conference proceedings 2019 2019-01 https://doi.org/10.18429/JACoW-LINAC2018-THPO103 http://jacow.org/linac2018/papers/thpo103.pdf The solid state amplifier is an important part of the RF power source system of ADS project at IHEP. Three kinds of solid state amplifier with different power and frequency have been applied. In this paper, the specifications of solid state amplifier are presented. In addition, the principle of breakdown of power modules during the high power test of coupler are analyzed.