Compact Tunable Balanced Dual-band Bandpass Filter Using Tri-Stub Loaded Resonator

作     者：Hong Yang Dewei Zhang Junjie Zhang Xian Wang Chenqing Pan Zhuang Ma Yufan Fu 

作者机构：China National Digital Switching System Engineering and Technology R&D Center Zhengzhou 450001 China. 

出 版 物：《Journal of Physics: Conference Series》 

年 卷 期：2021年第1914卷第1期

学科分类：07[理学] 0702[理学-物理学] 

摘      要：This letter proposes a tunable balanced dual-band bandpass filter (BPF) with high common-mode (CM) suppression based on tri-stub loaded resonator (TSLR). Two TSLRs terminated with varactor diodes are employed to obtain the tunable second differential-mode (DM) passband, which is independent of the first one. For validation, a tunable balanced dual-band BPF is designed, fabricated and measured that achieve the continuous frequency-tuning range of the second DM passband from 5.968 to 6.368 GHz with constant 3dB fractional bandwidth (FBW) of 6.8% ± 0.17% and CM rejection levels of over 30 dB. The measured results agree well with the simulated ones.