Microwave directional filter with quasi-elliptic response

Abstract From the Canadian patent

Circularly polarized radiation is tapped off from an input waveguide through an input iris into an entry cavity, where it is resolved into two orthogonal linearly polarized components. These respectively proceed along two discrete paths to an exit cavity. In each path six independently tunable resonances -traversed by both direct and bridge couplings -provide enough degrees of freedom for quasi-elliptic filter functions. In the exit cavity the resultants from the two paths are combined to resynthesize circularly-polarized radiation, which traverses another iris to the output waveguide. In one layout four resonant tri-mode cavities, form a rectangular array -- with entry and exit cavities at …