TRUE ELLIPTIC-FUNCTION FILTER USING TRIPLE-MODE DEGENERATE CAVITIES.

A six-pole triple-mode filter capable of a true elliptic-function response has been synthesized and experimentally realized. This was achieved by using a new intercavity iris structure that can control three intercavity-mode couplings simultaneously. The experimental results indicate that an excellent control of the degenerate mode excitation and intercavity mode coupling is possible. In addition to the reduction in size and weight, this filter provides a much larger Q than the corresponding dual-mode counter part.