Patent ID: 7538394

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 single connecting path connecting one of the control terminal pads and a corresponding gate; a first protecting element connected between the common input terminal pad and the single connecting path and comprising a first conduction region, a second conduction region and a first insulating region disposed between the first and second conduction regions; and a second protecting element connected between one of the output terminal pads and the single connecting path and comprising a third conduction region, a fourth conduction region and a second insulating region disposed between the third and fourth conduction regions, wherein the single connecting path comprises a high-resistance element that has a resistance higher than an average resistance of the single connecting path and is disposed between the first and second protecting elements that are disposed along the single connecting path.