Abstract: In order to realize an antenna for transmitting and receiving sharing, developing a high-power HF wideband T/R switch, it is mainly used for high frequency radar and high power HF communication system. Putting forward the switch circuit which taking the symmetric PIN diodes as the core from the view of improving the isolation, in order to reduce the switching time of switch, reduce power consumption and improve its stability, putting forward taking the unipolar pulse circuit as control pulse circuit of switch circuit, at the same time, putting forward the protection circuit of the receiver and transmitter. In the portable high frequency surface wave radar system, the crossed-loop/monopole antenna realize transmitting and receiving sharing through the high-power HF wideband T/R switch, simplifying the antenna system of portable high frequency surface wave radar, reducing the antenna area, also reducing the difficulty of erecting the antenna, This system has the characteristics of simple hardware circuit, low power consumption, stabilization and reliability.