Feasibility study on combline filter for tunable filters

In this paper, a combline filter is studied to see if the filter can be used for a reconfigurable filter that covers a frequency range of 2.0 GHz to 2.7 GHz and a bandwidth ranging from 50 MHz to 80 MHz. Since the bandwidth as well as the center frequency should vary in a wide range, the coupling between the load/source and the first/last resonator must be changeable. This study proves that the combline filter can meet the frequency requirements by designing the combline filter that meets four extreme frequency requirements using full-wave electromagnetic simulations. The input/output coupling proves that it can be tuned enough to be used for the reconfigurable filter of interest.