Dual-band-rejection filter for distortion reduction in RF transmitters

A novel concept of dual-band-rejection filter (DBRF) is proposed with its circuit synthesis procedure and an example of its realization with dielectric resonators at L-band. DBRF can make two closely-spaced rejection bands and a pass-band between them, with lower loss than a band-pass filter (BPF) having the same number of resonators and the same frequency-selectivity just around the pass-band. DBRF can be applicable to distortion reduction filter in RF transmitters.