Disclosed is a bandpass filter comprising a first resonator 1 to a sixth
resonator 6 having lengths of basically 1/4 wavelength, an input section
IN connected to an ungrounded end of the first resonator, and an output
section OUT connected to an ungrounded end of the sixth resonator,
wherein the second to fifth resonators 2-5 are electromagnetically
coupled with each other, the second and the third resonators are
respectively coupled to the first resonator via the first and the second
capacitances C1,C2, the third and the fourth resonators are respectively
coupled to the sixth resonator via the third and the fourth capacitances
C3,C4, and the input section IN and output section OUT are coupled to the
first resonator and sixth resonator through an input and output
capacitances C5, C6, respectively. This bandpass filter can be a small
size, low loss filter suitable for UWB (Ultra Wide Band).