An inductor circuit includes first inductive circuit, second inductive circuit, and third inductive circuit. First inductive circuit at receiver side has a first end coupled to a first port of an antenna and a second end coupled to an input port of a receiving circuit. Second inductive circuit at transmitter side has a first end and a second end respectively coupled to output ports of a power amplifier. Third inductive circuit at antenna side has a first end coupled to a first port of the antenna and having a second end. Second inductive circuit and the third inductive circuit are disposed on an outer ring to form a ring shape and the third inductive circuit is disposed on an inner ring within the outer ring to form a spiral shape. Third inductive circuit is disposed between the second inductive circuit and the first inductive circuit.