Ceramic Waveguide Filters with Improved Stop band Rejection and Transmission Zeros

This work presents the new design approach to enhance the spurious performance of monolithic ceramic waveguide filters with better selectivity. The monolithic ceramic waveguide filters offer considerable miniaturization when compared to TEM filters. Resonators of different widths with metal plated blind holes were used to achieve inter-resonator coupling and transmission zero while improving the stop band rejection of the filter. The proposed filter achieved excellent stop band performance of 1.65*f_o as compared to same width monolithic ceramic waveguide filter. The simulated results of 3rd order and 4th order filter were presented in this paper.