Patent ID: 7994873

Claim:
A balun device, comprising: a first inductance element having a first end and a second end, wherein the first end is for receiving an input signal; and a second inductance element having a third end and a fourth end, wherein the third end is for outputting a first output signal corresponding to the input signal, the fourth end is for outputting a second output signal corresponding to the input signal, the first output signal and the second output signal substantially have the same amplitude but have opposite phases, and the second inductance element and the first inductance element generate mutual inductance; a first capacitance element coupled to the first end; a second capacitance element coupled to the third end; a third capacitance element coupled to the fourth end; and a third inductance element having one end connected to one of the first capacitance element, the second capacitance element and the third capacitance element in series, the other end of the third inductance element is grounded.