Design of Quad-Band Filter Using SIR and DGS

A novel quad-band microstrip bandpass filter (BPF) using stepped impedance resonators (SIR), stub loaded resonator(SLR) and defect ground structure(DGS), which can be utilized in Fourth Generation Mobile Telephone Mobile Communication Standard(LTE-TDD), Direct To Home(DTH), 5-th Generation(5G) and Digital Microwave Relay Communication. The BPF was modeled and simulated by using the Ansys HFSS software. And the fabricated filter has the minimum insertion losses of 0.67 dB, 1.5 dB, 0.3 dB and 2.1 dB and the return losses 19.5 dB, 11.8 dB, 20.8 dB and 14.8 dB. By tuning the parameter of DGS, a multi-band filter can be easily optimized. This study provides a simple and effective method to design a quad-band filter with low insertion loss and compact size.