Switching circuit at high frequency with low insertion loss

摘要

In a switching circuit, low insertion loss and enough isolation can be ensured at a desired frequency at the same time. An inductor is externally connected in parallel with the path between the drain and source of each of field-effect transistors built in a switching integrated circuit, and the inductor and the OFF capacitance of the field-effect transistor are made to generate parallel resonance. At this time, by suitably adjusting the inductance, low insertion loss and enough isolation are ensured at a desired frequency at the same time.