High Performance Single-Ended Wideband and Balanced Bandpass Filters Loaded With Stepped-Impedance Stubs

Yongle Wu; Liwei Cui; Weiwei Zhang; Lingxiao Jiao; Zheng Zhuang; Yuanan Liu

doi:10.1109/ACCESS.2017.2695220

IEEE Access (Jan 2017)

High Performance Single-Ended Wideband and Balanced Bandpass Filters Loaded With Stepped-Impedance Stubs

Yongle Wu,
Liwei Cui,
Weiwei Zhang,
Lingxiao Jiao,
Zheng Zhuang,
Yuanan Liu

Affiliations

Yongle Wu: ORCiD; Beijing Key Laboratory of Work Safety Intelligent Monitoring, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, China
Liwei Cui: Beijing Key Laboratory of Work Safety Intelligent Monitoring, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, China
Weiwei Zhang: Beijing Key Laboratory of Work Safety Intelligent Monitoring, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, China
Lingxiao Jiao: Beijing Key Laboratory of Work Safety Intelligent Monitoring, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, China
Zheng Zhuang: Beijing Key Laboratory of Work Safety Intelligent Monitoring, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, China
Yuanan Liu: Beijing Key Laboratory of Work Safety Intelligent Monitoring, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, China

DOI: https://doi.org/10.1109/ACCESS.2017.2695220
Journal volume & issue: Vol. 5
pp. 5972 – 5981

Abstract

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High-performance single-ended wideband and balanced bandpass filters loaded with steppedimpedance stubs are proposed in this paper. For the proposed wideband filter and the differential mode of the proposed balanced filter, two transmission zeros near the passband are realized by using simple stepped-impedance stubs, which enhances the passband selectivity of these new filters. The analytical and accurate design equations for transmission poles and zeros of these single-ended and balanced filters are provided based on the scattering-parameters theory. The single-ended bandpass filter, employing a T-shaped structure to produce a wide passband, is achieved with 3-dB fractional bandwidth of 79.33%, 19-dB passband return loss, and 35-dB harmonic suppression (1.56f0-2.51f0, f0 is the center frequency of the wide passband). The 3-dB differential-mode fractional bandwidth of 33% with 22-dB passband return loss and the 30-dB harmonic suppression (1.29f0-2.67f0) are obtained in the proposed balanced bandpass filter. In addition, by inserting open-circuit stubs into the proposed balanced bandpass filter, over 25-dB common-mode suppression is obtained from 0 to 2.67f0. Good agreement is observed between the simulation and measurement results.

Published in IEEE Access

ISSN: 2169-3536 (Online)
Publisher: IEEE
Country of publisher: United States
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering
Website: https://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=6287639

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