Symmetrical Realization for Predistorted Microwave Filters

This paper presents a symmetric realization for a predistorted bandpass filter using a general cross-coupled resonator structure. The new method enables much simpler conversion from an existing filter design without predistortion. Hence both design and tuning efforts are reduced. A 10-4-4 dielectric resonator filter was built to verify the validity of the new method. The filter, coupled with an input circulator and output isolator was tested over temperature to validate the suitability for practical applications such as satellite transponder input multiplexers.