A microstrip planar lowpass filter with ultra-wide stopband using hexagonal-shaped resonators-Reference-Cited by-同舟云学术

A microstrip planar lowpass filter with ultra-wide stopband using hexagonal-shaped resonators

Published:2021-07-01 Issue:11-12 Volume:75 Page:547-552
ISSN:0016-1136
Container-title:Frequenz
language:en
Short-container-title:

Author:

Jiang Shu¹^ORCID,Wang Wenbo²,Ren Le²

Affiliation:

1. School of Information and Communication Engineering, Nanjing Institute of Technology , Nanjing 211112 , China

2. State Key Laboratory of Millimeter Waves , Southeast University , No. 2 Sipailou , Xuanwu District , Nanjing , China

Abstract

Abstract A microstrip planar lowpass filter with ultra-wide stopband up to 40 GHz is presented. The filter is designed based on four types of hexagonal-shaped resonators, producing multiple transmission zeroes and extending the stopband. The high-impedance transmission line is folded to make the circuit more compact and form the coupling gaps between the adjacent resonators. A pair of folded open stubs are added to enhance the cut-off rate. As a result, an ultra-wide stopband with 23rd-harmonic suppression has been attained. A demonstration filter has been designed and fabricated with 3 dB cut-off frequency of 1.70 GHz. The measured results show that the relative stop bandwidth of the low-pass filter (LPF) is 182% with suppression level of 25 dB, covering 1.85–40 GHz. The functional area size of the filter is 21.50 × 21.70 mm, which corresponds to 0.198λ g × 0.200λ g (λ g is the guided wavelength at 3 dB cut-off frequency).

Publisher

Walter de Gruyter GmbH

Subject

Electrical and Electronic Engineering

Link

https://www.degruyter.com/document/doi/10.1515/freq-2021-0031/pdf

Reference18 articles.

1. Y. Yang, X. Zhu, and N. C. Karmakar, “A novel microstrip lowpass filter using compact microstrip resonant cells and uniquely shaped defected ground structures,” Microw. Opt. Technol. Lett., vol. 54, no. 11, pp. 2462–2464, 2012, https://doi.org/10.1002/mop.27126.

2. L. Shi, Z. Fan, and D. Xin, “Miniaturized low‐pass filter based on defected ground structure and compensated microstrip line,” Microw. Opt. Technol. Lett., vol. 62, no. 3, pp. 1–5, 2020, https://doi.org/10.1002/mop.32144.

3. A. S. Mohra, “Microstrip low pass filter with wideband rejection using opened circuit stubs and Z-slots defected ground structures,” Microw. Opt. Technol. Lett., vol. 53, no. 4, pp. 811–815, 2011, https://doi.org/10.1002/mop.25876.

4. S. Sen, T. Moyra, and D. Sarkar, “Modelling and validation of microwave LPF using modified rectangular split ring resonators (SRR) and defected structures,” AEU-Int. J. Electron. C., vol. 88, pp. 1–10, 2018, https://doi.org/10.1016/j.aeue.2018.02.009.

5. M. A. Imani, F. Shama, M. Alirezapoori, and M. Ekhteraei, “Miniaturized microstrip lowpass filter using cylindrical-shaped resonators for integrated applications,” Analog Integr. Circuits Signal Process., vol. 95, no. 2, pp. 223–229, 2018, https://doi.org/10.1007/s10470-018-1176-7.