Bandwidth Tunable Optical Filter Based on the Quad-Mode Resonator
Zihan Zhang
Jikun Du
Jingwen Li
DOI: https://doi.org/10.59429/esta.v10i5.1446
Keywords: Resonator Filters; Microstrip Filters; Varactor Diodes
Abstract
An innovative bandwidth tunable optical filter with controllable bandwidth, center frequency, and transmission zero is proposed in this paper. The proposed filter utilizes a quad-mode resonator to achieve a wideband filter centered at 2.42 GHz. By incorporating varactor diodes into the open branches of the resonator, the proposed filter's center frequency and bandwidth can be dynamically adjusted via the voltage applied to the diodes. This tunable filter exhibits low insertion loss of less than 2 dB, return loss exceeding 10 dB, and a relative bandwidth of up to 40%.
References
Helaoui M, Boumaiza S and Ghannouchi FM, "Reconfigurable platform for software/hardware co-design of SDR base band pre-processing module", International Symposium on Antenna Technology and Applied Electromagnetics and Canadian Radio Sciences Conference, pp. 1-4, Jul. 2006.
Chen R. and Hashemi H, "Reconfigurable SDR receiver with enhanced front-end frequency selectivity suitable for intra-band and inter-band carrier aggregation", IEEE International Solid-State Circuits Conference (ISSCC), pp. 1-3, Feb. 2015.
Wünsche R., Collmann R., Krondorf M and Forster J, "Microstrip Combline Bandpass Filter with Tuning Range Enhancement and Bandwidth Tunability Using Resonator Loaded Series Varactor and SLR," 2022 14th German Microwave Conference (GeMiC), Ulm, Germany, 2022, pp. 148-151.
Lin F and Rais-Zadeh M, "Continuously Tunable 0. 55-1. 9-GHz Bandpass Filter With a Constant Bandwidth Using Switchable Varactor-Tuned Resonators[J]", IEEE Transactions on Microwave Theory and Techniques, vol. 65, no. 3, pp. 792-803, 2017.
Kim BK and Yun SW, "Varactor-tuned combline bandpass filter using step-impedance microstrip lines", IEEE Transactions on Microwave Theory and Techniques, vol. 52, no. 4, pp. 1279-1283, 2004.
Sanchez-Renedo M and Gomez-Garcia R, "Small-size planar tunable combline filter using decoupling walls", Electronics Letters, vol. 43, pp. 532-534, 02 2007.
Zhu D, "Research on miniature multimode filter[D]". Nanjing: Nanjing University of Science and Technology, 2015.