Patent ID: 6924707

Claim:
A resonator comprising: a multi-layer substrate having an upper and lower surface and including at least two grounding conductor layers and a plurality of dielectric layers, one of the at least two grounding conductor layers being disposed on the lower surface of the multi-layer substrate; a strip line disposed between the at least two grounding conductor layers; a microstrip line disposed on the upper surface of said multi-layer substrate; and a through hole formed in said dielectric layers to connect said strip line to said microstrip line; wherein portions of the one of the at least two grounding conductor layers that is closest to said microstrip line are omitted to define an omitted portion and a through hole in the one of the at least two grounding conductor layers that is closest to said microstrip line; the through hole in the one of the at least two grounding conductor layers is aligned with the through hole in said dielectric layers and the omitted portion is aligned with the microstrip line; and the through hole in the one of the at least two grounding conductor layers is spaced from the omitted portion such that the through hole in the one of the at least two grounding conductor layers is disposed outside of a periphery of the omitted portion.