SPST switch, SPDT switch, and communication apparatus using the SPDT switch

摘要

An SPST switch having a small transmission loss and a small power consumption is provided. The drain and the source of an FET are connected to each other in series through an induction element and a capacitor element, one terminal of the capacitor element is connected to a first terminal, the other terminal is connected to a second terminal, the gate of the FET is connected to a control terminal, the capacitance of the capacitor element is made equal to the OFF capacitance of the FET, and the inductance of the induction element is set to be such a value that the induction element resonates at a signal frequency with the capacitor element.