Patent ID: 7272367
Filing Date: 2007-09-18
Classification: H03H

Abstract:
1. A multiband filter circuit including: a first bandpass filter circuit; a second bandpass filter circuit having a center frequency higher than that of the first bandpass filter circuit; first mutual inductance having an inductance component connected between an input port and an input side of the first bandpass filter circuit and an inductance component connected between an output port and an output side of the first bandpass filter circuit; and second mutual inductance having an inductance component connected between the input side of the first bandpass filter circuit and an input side of the second bandpass filter circuit and an inductance component connected between the output side of the first bandpass filter circuit and an output side of the second bandpass filter circuit, wherein the input side and the output side of the first bandpass filter circuit are magnetically coupled to each other in a jump-coupling manner by the first mutual inductance, and the input side and the output side of the second bandpass filter circuit are magnetically coupled to each other in a jump-coupling manner by the second mutual inductance.