A low-pass filter (10) is provided. The low-pass filter includes an input part (100), an output part (120), a high impedance part (140), a first low impedance part (160), and a second low impedance part (180). The input part is electronically connected to the high impedance part for input of electromagnetic signals thereinto. The output part is electronically connected to the high impedance part for output of electromagnetic signals therefrom. The input part and the output part are asymmetrical to a resonator defined by the high impedance part, the first low impedance part and the second low impedance part. One end of the high impedance part is electronically connected to the first low impedance part, the other end of that is electronically connected to the second low impedance part. Wherein the high impedance part is disposed partly between the first low impedance part and the second low impedance part.