摘要 |
A microwave filter having a resonator comprising a cylindrical structure having conductive walls filled with a conductor material. The cylindrical structure is recessed inside a multi-layered substrate. First and second conductive coupling arms are disposed on the top layer of the substrate for coupling signals to the cylindrical structure. The conductive coupling arms are physically separated from the cylindrical structure by a dielectric layer. The first and second conductive coupling arms extend away from the center of the cylindrical structure to form a microstrip line. The cylindrical structure further comprises a bottom portion having a solid conductive bottom plate perpendicular to the axis of the cylinder. A bottom conductive ground layer separated from the conductive bottom plate by a second dielectric layer. |