When the attenuation pole occurs in, improvement and miniaturization of the filter are made possible by modifying the electric length with turning point and each filter. In order 1st bandpass filter 5 and 2nd bandpass filter 7 for the attenuation pole to occur at least on the one hand the 1st bandpass filter 5 which possesses the quality of center frequency f1 and center frequency f1 the 2nd bandpass filter 7 which possesses the quality of the center frequency f2 which differs and, 1st bandpass filter in the transmission circuit in kopurenahuiruta 3 which has with the turning point 11 which is formed 9 which connects with 5 and 2nd bandpass filter 7 and transmission circuit 9, it is designed, formation position of turning point 11 adjusts and the frequency limits which the attenuation pole occurs are adjusted.
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