Patent ID: 8188813

Claim:
A microwave filter having a plurality of resonators, said plurality of resonators comprising: cylindrical structures each having conductive walls filled with a conductor material, and each of said cylindrical structures recessed inside a multi-layered substrate; at least first and second conductive coupling arms disposed on a top layer of said multi-layered substrate for cross coupling signals between said cylindrical structures, said at least first and second conductive coupling arms being physically separated from said cylindrical structures by a dielectric layer of the multi-layered substrate, said at least first and second conductive coupling arms extending away from the centers of said cylindrical structures to form a microstrip line for cross coupling signals between adjacent cylindrical structures; said cylindrical structures further comprising a bottom portion having a solid conductive bottom plate perpendicular to an axis of the cylinder structures; and a bottom conductive ground layer separated from said conductive bottom plate by a second dielectric layer, wherein the coupling of said signals between said plurality of resonators of said filter is substantially through said at least first and second conductive coupling arms.