Compact tunable dual-band bandpass filter using open-loop resonator loaded by step impedances cells for multimode WLANs

Abstract

In this paper, a compact microstrip open-loop resonator loaded by step impedances cells, is designed to achieve dual-band bandpass filter with tunable resonance frequencies. By adjusting the lengths and widths of the step impedances and the dimensions of the open loop resonator, the simulation results shows the dual-band feature of two passbands at 2.4 and almost 5.2GHz (exactly 5.25). The insertion losses are 0.2 dB and 0.4 dB at the 2.4GHz and 5.2 GHz respectively. There is a good agreement between simulation and measurement results. © IEICE 2014.