Tunable dual‐mode microstrip patch resonators and filters. Issue 6 (1st April 2013)

• Record Type: Journal Article
• Authors: Tang, Hui; Chen, Jian‐Xin; Zhou, Li‐Heng; Bao, Zhi‐Hua
• Is Part Of: IET microwaves, antennas & propagation. Volume 7:Issue 6(2013)
• Page Start: 408
• Page End: 414
• Publication Date: 2013-04-01
• Subjects: band‐pass filters -- circuit tuning -- microstrip filters -- microstrip resonators -- resonator filters -- transmission lines; electric field distributions -- ground plane -- square loop slot -- microwave transmission line -- return path -- signal line -- frequency agility -- microstrip bandpass filters -- dual mode microstrip patch resonators; Microwaves -- Periodicals; Microwave antennas -- Periodicals; Antennas (Electronics) -- Periodicals; Radio wave propagation -- Periodicals; Microwave communication systems -- Periodicals; 621.381305
• DOI: 10.1049/iet-map.2012.0398
• Languages: English
• ISSNs: 1751-8725

Abstract

Abstract : In this study, tunable dual‐mode microstrip patch resonators are presented and utilised to design microstrip bandpass filters (BPFs). The novelty of the designs lies in that the performance of frequency agility can be realised by using either the signal line or the return path (the ground) of microwave transmission line. For the proposed resonators, the resonant frequencies of two coupled degenerate modes can be tuned using a square‐loop slot with loaded tunable capacitors on the ground plane or on the patch. The locations of the capacitors are determined according to the electric field distributions of the two orthogonal modes. The variations of the modes in spectrum are studied. Finally, two types of demonstration compact tunable BPFs are designed and fabricated, and the simulated and measured results show good agreement.