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Application of compact folded-arms square open-loop resonator to bandpass filter design

Application of compact folded-arms square open-loop resonator to bandpass filter design

Nwajana, Augustine ORCID: 0000-0001-6591-5269 and Obi, Emenike Raymond (2023) Application of compact folded-arms square open-loop resonator to bandpass filter design. Micromachines, 14 (2):320. ISSN 2072-666X (Online) (doi:

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Folded-arms square open-loop resonator (FASOLR) is a variant of the conventional microstrip square open-loop resonator (SOLR) that facilitates further device size miniaturization by having the two arms of the conventional SOLR folded inwards. This paper highlights the benefits of this brand of compact SOLR by implementing a five-pole Chebyshev bandpass filter (BPF) using compact FASOLR. The test BPF is presented, with centre frequency of 2.2 GHz, fractional bandwidth of 10%, passband ripple of 0.04321 dB, and return loss of 20 dB. The design is implemented on a Rogers RT/Duroid 6010LM substrate with a dielectric constant of 10.7 and thickness of 1.27 mm. The filter device is manufactured and characterised, with the experimentation results being used to justify the simulation results. The presented measurement and electromagnetic (EM) simulation results demonstrate a good match. The EM simulation responses achieve a minimum insertion loss of 0.8 dB and a very good channel return loss of 22.6 dB. The measurement results, on the other hand, show a minimum insertion loss of 0.9 dB and a return loss of better than 19.2 dB. The filter component has a footprint of 36.08 mm by 6.74 mm (that is, 0.26 λg x 0.05 λg), with λg indicating the guided wavelength for the 50 Ohm microstrip line impedance at the centre frequency of the proposed fifth-order bandpass filter.

Item Type: Article
Additional Information: This article belongs to the Special Issue Design Trends in RF/Microwave Filtering and Memristive Devices.
Uncontrolled Keywords: resonator; half-wavelength; square open-loop; folded-arms square open-loop; bandpass filter; coupling; microstrip
Subjects: Q Science > QA Mathematics > QA76 Computer software
T Technology > TK Electrical engineering. Electronics Nuclear engineering
T Technology > TS Manufactures
Faculty / School / Research Centre / Research Group: Faculty of Engineering & Science
Faculty of Engineering & Science > Engineering Design in Practice
Faculty of Engineering & Science > Future Technology and the Internet of Things
Faculty of Engineering & Science > School of Engineering (ENG)
Faculty of Engineering & Science > Wolfson Centre for Bulk Solids Handling Technology
Last Modified: 30 Jan 2023 08:02

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