Fully reconfigurable filter based on a microstrip patch resonator with low-voltage driving

An approach to bandwidth- and frequencyreconfigurable planar filters is proposed. Switching elements are used in a modified dual-mode microstrip resonator to independently tune the centre frequency (up to 10 %) and the bandwidth (4%) of the filter. In order to demonstrate the feasibility of the proposed approach the design of a 2
^nd
-order tunable filter is presented along with simulation and measurement results. Measurement results showed an average Insertion Loss (IL) of 2 dB and return loss better than 12 dB. Bandwidth and frequency tuning range are 4% and 10% respectively as simulated.