Mode filter apparatus

In a power combiner apparatus, a mode filter apparatus for multi-moded structures comprising in combination:

• a lower member being equally disposed about a center line, said lower member encompassing a bias resistor network, said bias resistor network extending radially from said center line, said bias resistor network having a common point at said center line, said lower member having an input bias connector connected to said common point of said bias resistor network,
• an upper plate mated with said lower member to form an enclosed cavity, said upper plate having a plurality of diodes mounted in said upper plate around the periphery thereof, said plurality of diodes respectively having one end connected to said bias resistor network, said upper plate having a coupling probe mounted in the center thereof, said coupling probe interacting with said plurality of diodes to conduct the electromagnetic radiation received therefrom and present in said cavity, and,
• a mode filter means located on said lower member in said cavity, said mode filter means comprising a conductive material covering the top of said lower member to a predetermined height but not filling said cavity, said mode filter means having a plurality of resonant slots therein on said cavity side, said plurality of resonant slots extending radially from the center of said mode filter means toward the outer edge of said mode filter means, said plurality of resonant slots being arranged in a predetermined pattern, said predetermined pattern for said plurality of resonant slots includes resonant slots of varying length, width and depth, each slot of said plurality of resonant slots having an absorbing material positioned therein, said absorbing material filling the bottom of each slot of said plurality of resonant slots and extending therefrom to a predetermined height.