Patent ID: 7508285
Filing Date: 2009-03-24
Classification: H03H

Abstract:
1. A band pass filter circuit, wherein said band pass filter passes a passband which is a frequency band between a first cutoff frequency and a second cutoff frequency with respect to an input frequency of an inputted input signal, said band pass filter circuit comprising: a first resonant circuit configured to be connected to a signal line in series and set a first resonant frequency as said first cutoff frequency; a second resonant circuit configured to be connected to said signal line in series and set a second resonant frequency as said second cutoff frequency; a third resonant circuit configured to be connected to said signal line in parallel at a connection node where said first resonant circuit and said second resonant circuit are connected, and set a third resonant frequency as a band-pass center frequency between said first cutoff frequency and said second cutoff frequency; and at least one of a capacitive circuit configured to be installed between said first resonant circuit and said connection node and an inductive circuit configured to be installed between said second resonant circuit and said connection node.