Patent ID: 8450805

Claim:
A compound semiconductor switch circuit device comprising: two or more switching elements formed on a compound semiconductor substrate, each of the switching elements comprising at least one gate, a signal input portion and a signal output portion; a common input terminal pad formed on the substrate and connected with the signal input portions of the switching elements; an output terminal pad provided for each of the switching elements and connected with a corresponding signal output portion, the output terminal pads being formed on the substrate; a control terminal pad provided for each of the switching elements and connected with a corresponding gate, the control terminal pads being formed on the substrate; a connecting path connecting one of the control terminal pads and a corresponding gate; and a protecting element connected between the common input terminal pad and the connecting path and comprising a first conduction region, a second conduction region and an insulating region disposed between the first and second conduction regions, wherein the connecting path comprises a high-resistance element that has a resistance higher than an average resistance of the connecting path and is disposed between the protecting element and the control terminal pad with which the connecting path is connected.