New 4-pole dual-mode resonator filter using composite-right/left-handed line

A new 4-pole dual-mode resonator filter is reported. The main feature of this dual-mode resonator filter is the suppression of the second harmonic, achieved by using composite- right/left-handed line in a ring resonator. The discrete capacitors used in the design have been carefully modeled and discussed. The filter was simulated using an em simulator and the optimized frequency response showed good agreement with the measured response. The same dual-mode resonator can be used to design quasi-elliptic function filters and this will be investigated.