Low-loss high-power single pole single throw (SPST) monolithic RF switch based on AlGaN/GaN hetero-junction field effect transistors (HFETs) demonstrate the insertion loss and isolation of 0.15 dB and 45.9 dB at 0.5 GHz and 0.23 dB and 34.3 dB at 2 GHz. Maximum switching powers are estimated +47 dBm or higher. Factors determining the maximum switching powers are analyzed. Design principles to obtain equally high switching powers in the ON and OFF-states are developed. (C) 2008 Elsevier Ltd. All rights reserved.