Patent ID: 7956706

Claim:
A multiband filtering apparatus for use in a communications system, said apparatus including: a housing; a plurality of cavities disposed within said housing wherein each cavity includes a resonant structure, each resonant structure having at least one ceramic element, and at least one conductive post adjacent the ceramic element, each conductive post including a bore, and wherein said plurality of cavities are suitably dimensioned to allow for the propagation of at least two independent passbands; at least one input port coupled to a first resonant structure of said plurality of resonant structures; at least one output port coupled to a second resonant structure of said plurality of resonant structures; a closure member adapted to engage said housing and cap said plurality of cavities; and a plurality of tuning rods, each tuning rod being associated with the at least one conductive post within each resonant structure such that a portion of each tuning rod is received within the bore of its associated conductive post; and wherein at least one passband is propagated as a TM01δ mode and at least one passband is propagated as a TE01δ mode.