An ultra-wideband bandpass filter using a new defected ground structure resonator and interfinger-capacitor microstrip is proposed,which is constructed by a cascading microstrip high-pass filter and a low-pass filter.The low-pass filter with a 3 dB cutoff frequency of 6 GHz is composed of a widened microstrip line on the top plane and a combined open-loop defect ground structure on the ground plane,achieving high selectivity and good stopband performance.The high-pass filter consists of a microstrip interfinger capacitor in the top plane and an open-loop defect ground structure in the ground plane,resulting in two transmission zeros and steep selectivity.The designed ultra-wideband bandpass filter has a 3 dB bandwidth of 2.5 GHz and a center frequency of 4.8 GHz,showing a sharp cut-off frequency response.It also exhibits good stopband performance,with lower stopband from DC to 3.45 GHz and upper stopband from 6.4 to 12 GHz,suppressing better than 20 dB.
关键词
带通滤波器/缺陷地结构/谐振器/阻带/带宽/截止频率
Key words
bandpass filter/defected ground structure/resonator/stopband/bandwidth/cut-off frequency
维普
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