CONDUCTOR LOADED RESONATOR FILTERS WITH WIDE SPURIOUS-FREE STOPBANDS

A new configuration of conductor loaded resonator filters using two di fferent size conductor loaded resonators and enclosures with significa ntly improved spurious performance is presented. A rigorous mode-match ing method is used to compute the resonant frequencies, unloaded Q, an d the fields of the resonant modes of the conductor (solid or ring) lo aded resonators. The coupling coefficients between two resonators are computed using small aperture coupling theory. The stopband characteri stics of the filter are investigated. An eight-pole elliptic-function filter was designed, constructed, and tested. Extremely wide spurious- free stopband filter response was obtained which verified the theory.