Novel Compact Hairpin SIR Bandpass Filters with Defected Ground Structure

Three types of hairpin SIR bandpass filters with sizes reduction and spurious responses suppression which operate at S waveband are proposed, their performances are calculated and optimized. In these novel structures, split ring stepped-impedance resonator and DGS techniques are applied to not only reduce the size but also improve the filter frequency responses. The filters designed in this paper have advantages such as compact, simple and novel structures, smaller sizes compared to the traditional SIR bandpass filters, high selectivity, low passband insertion losses, wide stopband responses and so on.