Patent attributes
A substantially circular electrode 3 is arranged on a surface 2A of a dielectric substrate 2 of a TM010-mode resonator 1. A coupling line 5, which extends along a diameter of the substantially circular electrode 3, is arranged on a back surface 2B of the dielectric substrate 2, and back-surface electrodes 7 are arranged with the coupling line 5 interposed therebetween in the width direction. Furthermore, signal lines 11 and ground electrodes 13 are arranged on a surface of an external substrate 10 in positions other than portions facing the coupling line 5 of the TM010-mode resonator 1. The signal lines 11 are connected to the coupling line 5 of the TM010-mode resonator 1 and the ground electrodes 13 is connected to the back-surface electrodes 7.