Quad-band bandpass filter with controllable frequencies using asymmetric stub-loaded resonators. Issue 13 (2nd September 2017)

• Record Type: Journal Article
• Authors: Gao, Li; Zhang, Yao; Xu, Jin-Xu; Zhao, Xiao-Lan
• Is Part Of: Journal of electromagnetic waves and applications. Volume 31:Issue 13(2017)
• Page Start: 1255
• Page End: 1264
• Publication Date: 2017-09-02
• Subjects: Quad-band bandpass filter -- controllable frequencies -- asymmetric stub-loaded resonator -- compact size; Electromagnetic waves -- Periodicals; Electromagnetic devices -- Periodicals; 621.3
• DOI: 10.1080/09205071.2017.1341347
• Languages: English
• ISSNs: 0920-5071

Abstract

Abstract: In this paper, we present a compact quad-band bandpass filter (BPF) using asymmetric stub-loaded resonators. The resonator consists of a main transmission line with a short stub and two pairs of open stubs with different lengths. The whole resonator can be regarded as two different half-wavelength resonators and a simple stub-loaded resonator. Therefore, the resonator consists of four controllable modes, which are utilized to realize a quad-band response. Meanwhile, by using hook shape feed lines and source-load coupling structure, transmission zeros are generated near the passband, resulting in high selectivity. For demonstration, a compact quad-band BPF with operating frequencies of 1.57/2.45/3.5/5.15 GHz is implemented. Good agreement between the measured and simulated results is presented to verify the theoretical prediction.