Patent ID: 8598629

Claim:
A high-frequency device having a switching circuit, the device comprising: an insulating substrate; a compound semiconductor substrate on the insulating substrate; an active region on a first main surface of the compound semiconductor substrate, the first main surface facing away from the insulating substrate; a first high-frequency input/output terminal on the insulating substrate; a second high-frequency input/output terminal on the insulating substrate; a control signal input terminal on the insulating substrate; a power supply connection terminal on the compound semiconductor substrate; a ground terminal on the insulating substrate; a voltage-applying electrode on the compound semiconductor substrate; and a resistor in the compound semiconductor substrate, wherein, the voltage-applying electrode is in direct contact with the first main surface of the compound semiconductor substrate such that a predetermined positive voltage from the power supply connection terminal can be applied to the compound semiconductor substrate via the voltage-applying electrode, the resistor is formed as a circuit element in the compound semiconductor substrate and is disposed between the power supply connection terminal and the voltage-applying electrode, the switching circuit includes a field-effect transistor located within the active region on the first main surface of the compound semiconductor substrate, and the compound semiconductor substrate is electrically isolated by the insulating substrate from the other elements of the high-frequency device.