Dual-Band Bandstop Filter Based on Predistortion Hybrid Reflection Function

This paper presents an approach to realize a dual-band microwave bandstop filter based on predistortion reflection mode of a hybrid filtering function. A product of any two suitable classical filtering functions either from the same or different classes can form a hybrid dual-band filtering functions. Under multi-stage predistortion reflection mode technique, the predistorted hybrid lowpass reflection function can be synthesized using unified cascaded synthesis. This yields multiple lumped Brune sections and second order crosscoupled Brune sections to be extracted. To prove the synthesis, a 4th order hybrid Chebyshev and Butterworth filtering has been synthesized and simulated in Advanced System Design (ADS).