Patent ID: 7382211

Claim:
A non-reciprocal circuit device comprising: a first inductance element disposed between a first input/output port and a second input/output port, a second inductance element disposed between said second input/output port and a ground, a first capacitance element constituting a first parallel resonance circuit with said first inductance element, a second capacitance element constituting a second parallel resonance circuit with said second inductance element, a resistance element parallel-connected to said first parallel resonance circuit, and an impedance-adjusting means disposed between said first input/output port and said first inductance element, said impedance adjusting means being constituted by a third inductance element and/or a third capacitance element, wherein said first inductance element and said second inductance element are formed by a first central conductor and a second central conductor disposed on a ferrimagnetic member, said first central conductor having a smaller inductance than that of said second central conductor.