A compact quad-band bandpass filter with mixed electric and magnetic coupling. Issue 5 (10th April 2019)

• Record Type: Journal Article
• Authors: Zhou, Jie; Wang, Litian; Wang, Zhipeng; Zhang, Shengfang; He, Ming
• Editors: Boria, Vicente E.; Martín, Teresa; Burgos, Mateo
• Is Part Of: International journal of microwave and wireless technologies. Volume 11:Issue 5/6(2019)
• Page Start: 517
• Page End: 522
• Publication Date: 2019-04-10
• Subjects: Compact size, -- controllable bandwidths, -- mixed electric and magnetic coupling (MEMC), -- quad-band BPF; Wireless communication systems -- Periodicals; Microwave circuits -- Periodicals; Radio frequency -- Periodicals; 621.381305
• DOI: 10.1017/S1759078719000357
• Languages: English
• ISSNs: 1759-0787

Abstract

Abstract: In this paper, based on a novel multimode stub-loaded resonator, a second-order quad-band bandpass filter (BPF) with mixed electric and magnetic coupling is presented. The electric coupling and magnetic coupling are realized by arranging the parallel coupled lines and the grounded stub, respectively. Eight controllable resonant modes can be simultaneously excited and easily tuned. Eight transmission zeros are created, enhancing the passband selectivity. In addition, the bandwidths can be controlled independently by adjusting the coupling strength. A quad-band BPF centering at 0.67, 1.51, 2.84, 3.58 GHz with respective 3 dB fractional bandwidths of 13.4, 15.6, 9.2, 11.5% is designed, fabricated, and measured. The filter is compact with overall size 0.058 λ g × 0.13 λ g . The measured results show a good consistence with the simulated ones.