Compact and High Performance Bandpass Filter Based on an Improved Hybrid Resonator Using Beeline Compact Microstrip Resonator Cell (BCMRC)

• Published in: Journal of electromagnetic waves and applications Vol. 25; no. 11-12; pp. 1525 - 1535
• Main Authors: Ji, Y.-X., Xu, J., Niu, Y.-M., Hua, C.-Z., Chen, C.-H., Wu, W.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.01.2011
• ISSN: 0920-5071; 1569-3937
• DOI: 10.1163/156939311797164990

In this paper, a compact microstrip bandpass filter is presented by using a proposed improved hybrid resonator. Without requiring the cross-coupling and the source-load coupling, the new filter has a transmission zero on the upper stopband to provide a high selectivity. The fabricated filter is designed at f 0 = 1 GHz and has a compact size of 0.112λ g ×0.057λ g . Good agreement is observed between the measurements and simulations. The measured results show that the new filter has a wide −60 dB rejection upper stopband from 1.24f 0 to 4.05f 0 . In addition, a −20 dB rejection ultra-wide upper stopband is measured from 1.08f 0 to 15.38f 0 . The new filter can be fabricated using the standard printed-circuit-board (PCB) process and has a planar topology, which is easily integrated with the modern wireless communication system.