MICROWAVE DIRECTIONAL FILTER WITH QUASI-ELLIPTIC RESPONSE

摘要

Circularly polarized radiation is tapped off from an input waveguide (IWG) through an input iris (a) into an entry cavity (A), where it is resolved into two orthogonal linearly polarized components (H, V). These respectively proceed along two discrete paths to an exit cavity (D). 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 (g) to the output waveguide (OWG). In one layout, four resonant tri-mode cavities form a rectangular array with entry and exit cavities at diagonally opposite corners - and intermediate cavities for the two discrete paths in the two remaining corners. In another layout, six dual-mode cavities form a three-dimensional array: entry and exit cavities stacked one above the other, and two intermediate two-cavity stacks for the two discrete paths adjacent the entry/exit stack.