Patent ID: 7656254

Claim:
A dielectric filter comprising: a dielectric substrate having a first surface and a second surface; a ground electrode provided on the first surface of the dielectric substrate; a plurality of electrodes provided on the second surface of the dielectric substrate; and an input-output terminal coupled to a resonator formed by the ground electrode and any one of the plurality of electrodes, wherein at least two electrodes of the plurality of electrodes each comprise a quarter wavelength resonant line, a first end of each of the at least two electrodes connected to the ground electrode via a respective side-surface electrode provided on a side surface of the dielectric substrate and a second end of each of the at least two electrode being open, wherein at least a third electrode of the plurality of electrodes comprises a half wavelength resonant line, a first end of the third electrode being opened near a first of the quarter wavelength resonant lines and a second end of the third electrode being opened near a second of the quarter wavelength resonant lines, and wherein at least one of the first and second quarter wavelength resonant lines includes a parallel portion parallel to the half wavelength resonant line and a flexion that is jump-coupled to the other of the first and second quarter wavelength resonant lines.