Filter design with lossy circuit elements

Resonator losses in narrow-band microwave filters can lead to an unacceptable deterioration in performance. To avoid these effects large high Q resonators are often used. Alternatively, predistortion techniques may be used to correct for the effects of losses in bandpass filters. There is little information in the available literature on predistorted bandstop filters. In this paper a brief description of the effects of losses is followed by a review of classical predistortion for bandpass filters. This is followed by a presentation of new design techniques for predistorted transmission and reflection mode filters