volume | PIER Journals

Abstract

A novel circuit structure is proposed to design a small size band-stop filter. The structure consists of five pairs of short coupled-lines. The bandwidth, roll off and center frequency of the filter can be flexibly controlled by changing the data of different pairs of coupled-lines. By disconnecting the left-most pair of coupled-lines, the band-stop filter can be transformed into a full resistance filter. The center frequency of the band-stop filter is 2.40 GHz. The measured 20-dB stopband insertion loss bandwidth is 29.2% (2.05-2.75 GHz, the highest measured rejection is 44.21 dB). The simulation results agree well with the measured ones, which verifies the effectiveness of the proposed structure. The use of coupled-lines makes the structure more compact. The circuit size is 0.35λ_g × 0.27λ_g (25.63 mm × 19.70 mm).

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doi:10.1002/9781118197981

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Ms. Mengxin He

Dr. Xiaoying Zuo

Dr. Hang Mei

Dr. Yajian Li