HIGH FREQUENCY SWITCHING CIRCUIT

PURPOSE:To limit the occupied band width at high-frequency and high-power board band signal switching without providing a high-frequency filter, by detecting a zero cross signal and providing synchronism to a control signal. CONSTITUTION:A zero cross signal (d) of a high frequency signal (a) applied to an input terminal 1 is picked up at a zero cross detecting circuit 6, given to a control signal generating circuit 5, synchronizes a control signal (b) to obtain a switch controlling signal (e), which changes over a semiconductor switch 2, allowing to output a high-frequency output signal c' at an output terminal 4. Thus, the generation of unnecessary waves can be prevented and a high-frequency filter can be omitted, then the limit of occupied band width at high frequency switching can be done inexpensively easily.