Patent ID: 6914497
Filing Date: 2005-07-05
Classification: H01P

Abstract:
1. A parallel multistage band-pass filter comprising: a plurality of j resonators having adjacent resonance frequencies and connected in parallel to each other between an input terminal and an output terminal for a transmission signal in which, is a natural number greater than 1; a first transmission line having an electrical length substantially equal to half of a wavelength of the transmission signal incorporated between a first port on an input terminal side of a (2n−1)th resonator of the plurality of resonators numbered from the input terminal side and a second port on an input terminal side of a (2n)th resonator of the plurality of resonators numbered from the input terminal side; and a second transmission line having an electrical length substantially equal to half of a wavelength of the transmission signal incorporated between a third port on an output terminal side of the (2n)th resonator of the plurality of resonators numbered from the input terminal side and a fourth port on an output terminal side of a (2n+1)th resonator of the plurality of resonators numbered from the input terminal side, in which n is a natural number, wherein a number of transmission lines in the band-pass filter is equal to j−1 n a substantially λ/2 line equivalent.