Patent ID: 8847706

Claim:
A multiband-pass filter including multiple resonators formed on a dielectric substrate comprising three or more dielectric layers, the multiband-pass filter comprising: a ground conductor; wherein, each of the resonators comprises: a main-line conductor and a sub-line conductor formed on any of the dielectric layers; a sub open stub formed on a dielectric layer on which neither of the main-line conductor and the sub-line conductor is formed; a main open stub formed on a dielectric layer on which none of the main-line conductor, the sub-line conductor and the sub open stub is formed; a short-circuit conductor electrically connecting one end of the main-line conductor to one end of the sub-line conductor and to the ground conductor; a main through conductor electrically connecting the other end of the main-line conductor to one end of the main open stub, the end of the main open stub being aligned with that other end of the main-line conductor; and a sub through conductor electrically connecting the other end of the sub-line conductor to one end of the sub open stub, the end of the sub open stub being aligned with that other end of the sub-line conductor; any two of the resonators comprising an input-output line conductor connected to the main-line conductor.