Patent ID: 7176768

Claim:
A balanced high-frequency device comprising: a balanced element; at least one balanced terminal connected to the balanced element; a phase circuit having at least first, second, and third impedance elements, and electrically connected between the balanced element and the balanced terminals; wherein the first impedance element and the second impedance element are connected between the balanced terminals in series, the connection point between the first impedance element and the second impedance element is grounded through the third impedance element, a series resonant circuit is formed by the first impedance element and the third impedance element, a series resonant circuit is formed by the second impedance element and the third impedance element, an impedance to a differential signal component in the passing band of the balanced element of the first and second impedance elements is set so as to increase to the ground plane, the balanced elements are surface acoustic wave filters, the surface acoustic wave filters respectively have a piezoelectric substrate and IDT electrodes serving as a plurality of inter-digital transducer electrodes formed on the piezoelectric substrate, and at least one of the IDT electrodes is connected to a balanced input terminal or balanced output terminal.