Compact Wideband BPF With Wide Stopband Using Substrate Integrated Defected Ground Structure

In this letter, a compact wideband bandpass filter (BPF) with wide stopband is proposed based on the substrate integrated defected ground structure (SIDGS) and folded stepped-impedance resonator (FSIR). Such SIDGS can not only allocate specific resonance size but also introduce different harmonic positions compared traditional microstrip line resonator. Meanwhile, due to discrepant of FSIR, response be achieved using stacked-coupled scheme. To verify mechanism, miniaturized BPF operating at 1.69 GHz (i.e., f 0 ) implemented fabricated. A measured up 11.8 20-dB rejection level achieved.