Novel adaptive predistortion technique for cross coupled filters

This paper presents a novel adaptive predistortion technique for general cross-coupled microwave/RF filters with improved insertion loss and group delay equalization. The method enables many potential applications of an almost abandoned technique, especially using a lower Q design to emulate the performance of a higher Q filter. A 10-4-4 coaxial filter was built to verify the validity of the new method. The technique should lead to practical applications such as satellite transponder input multiplexers.