A compact trisection microstrip bandpass filter with frequency-dependent cross-coupling. Issue 7 (3rd October 2017)

• Record Type: Journal Article
• Authors: Wu, X. H.; Wei, X. B.; Lv, H. G.; Shi, Y.
• Is Part Of: Electromagnetics. Volume 37:Issue 7(2017)
• Page Start: 454
• Page End: 461
• Publication Date: 2017-10-03
• Subjects: Bandpass filter -- stub loaded ring resonator -- double-loop ring resonator -- embedded -- frequency-dependent cross-coupling -- transmission zeros; Electromagnetism -- Periodicals; 537
• DOI: 10.1080/02726343.2017.1376903
• Languages: English
• ISSNs: 0272-6343

Abstract

ABSTRACT: A compact microstrip bandpass filter using stub loaded ring resonators and double-loop ring resonators in an embedded triplet configuration with frequency-dependent cross-coupling is proposed in this article. The embedded triplet configuration is realized by putting the loops of the double-loop ring resonator into the circles of the stub loaded ring resonators. The frequency-dependent cross-coupling has been introduced to the filter by a manner of separate electric- and magnetic-coupling path. Three transmission zeros are obtained to enhance the frequency selectivity and stopband performance. Among them, two are achieved by the frequency-dependent cross-coupling, the other one is created by the harmonic effect of the transmission lines. The filter is designed for 2.4 GHz Wireless Local Area Networks application with 20.8% fractional bandwidth. The measured results show reasonable agreement with the simulated ones.