Design a compact tri-band band pass filter using asymmetric SIRs and DGS

In this research, a novel compact tri-band microstrip bandpass Filter is design using Asymmetric SIRs and DGS to achieved the characteristic of low insertion loss, high selectivity, wider range of bandwidth, low group delay for WiMAX (2.5GHz), WiMAX (3.4GHz) and UWB applications. The novel filter is design intentionally selecting the impedance ration(R) and length of the microstrip of the asymmetric SIRs and DGS is used to improve the coupling strength of the last band. The measurement entities of the novel filter for WiMAX (2.5GHz), WiMAX (3.4GHz) and UWB (4.12-5.32GHz) are insertion losses (S21) are -0.26dB, -0.07dB, -0.05dB, and return losses (S11) are -11.29dB, -19.25dB and -22.64dB respectively. The response of the filter was simulated using Ansoft HFSS Simulator.