Development of Wideband Microstrip Bandpass Filters Using DGS and Stub

Abstract

This research paper proposed the development of wideband microstrip bandpass filters using defected ground structure (DGS) with folded spurline structure and stub. DGS with folded spurline structure provided the resonant frequencies at 2.1 GHz and 3.3 GHz, respectively. From the measured results of the proposed filters, it obtained the center frequency of 2.89 GHz with a wide bandwidth of 64.70 %, the transmission coefficients of -3 dB and reflection coefficients of -16 dB. The transmission coefficients were reduced to -15 dB at the stopband of 4.5 - 8.0 GHz. The simulated results and experimental results were in good agreement.