A Compact Dual-Band Microstrip Bandpass Filter Using Meandering Stepped Impedance Resonators

This letter presents a compact dual-band microstrip bandpass filter (BPF) using meandering stepped impedance resonators (SIRs) with a coupling scheme, which exhibited a size reduction of 50% compared with the traditional direct coupling structure at the same frequency. With the new structure, dual-band BPF centered at 10.7/15.8GHz. The isolation between these two passbands is better than 25 dB form 11.5 to 14.5 GHz. It is shown that the measured and simulated performances are in good agreement. The BPFs achieved insertion loss of less than 2 dB and return loss of greater than 20 dB in each band.