Wide stopband bandpass filter based on dual-plane microstrip/interdigital DGS slot structure

• DOI: 10.1049/el.2009.2972
• Publication Date: 2009-12-04T14:37:37Z
• Authors: L.-Y. Ren; H. He
• Keywords: Stopband; Passband; Elliptic filter; Transition band; Butterworth filter

A novel bandpass filter with a wide stopband is presented. The proposed based on dual-plane structure consisting of microstrip and defected ground (DGS) slot an interdigital shape. Using this structure, the not only creates two transmission zeros near passband, but also exhibits upper stopband. equivalent-circuit model derived for filter. centred at 2.5 GHz 14.8% fractional bandwidth designed implemented, which shows minimum passband insertion loss 1.78 dB rejection better than 22 up to 12f0, where f0 stands centre frequency.