Design of a wide-stopband bandpass filter using stepped impedance resonators

X.-B. WeiResearch Institute of Electronic Science and Technology, University of Electronic Science and Technology of China, Chengdu, 611731, China;State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 611731, China

S.-L. YuanResearch Institute of Electronic Science and Technology, University of Electronic Science and Technology of China, Chengdu, 611731, China

J.-X. LiaoResearch Institute of Electronic Science and Technology, University of Electronic Science and Technology of China, Chengdu, 611731, China

P. WangResearch Institute of Electronic Science and Technology, University of Electronic Science and Technology of China, Chengdu, 611731, China

Z.-Q. XuResearch Institute of Electronic Science and Technology, University of Electronic Science and Technology of China, Chengdu, 611731, China

Y. ShiState Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 611731, China

Abstract

In this paper, a compact bandpass filter (BPF) with improved stopband characteristics using stepped impedance resonators (SIRs) is proposed. The filter consists of two quarter-wavelength SIRs with radial stubs and a PI-network of capacitance, which is used to suppress the upper frequency spurious signals. An odd- and even-mode analysis is adopted considering the structure’s symmetry. A new BPF centered at 1.57 GHz has been designed and fabricated to verify the validity of the proposed method. Measured results are in good agreement with the electromagnetic simulation. The frequency selectivity was enhanced via introducing two finite transmission zeros (TZs) near the passband, located at 1.21 GHz with 43.5 dB rejection and 3.10 GHz with 62.3 dB rejection, respectively. The spurious frequencies of the upper stopband are suppressed better than 20 dB from 2.07 to 16.25 GHz. And the circuit only occupies 0.09 λ_g × 0.09 λ_g.

Keywords:

Acknowledgments

This work was supported by the National Natural Science Foundation of China (51172034) and the Fundamental Research Funds for the Central University of UESTC (ZYGX2010J120).

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Order Reprints Request Corporate Permissions

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

Request Academic Permissions

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.

Design of a wide-stopband bandpass filter using stepped impedance resonators

Information for

Open access

Opportunities

Help and information

Design of a wide-stopband bandpass filter using stepped impedance resonators

Abstract

Acknowledgments

Reprints and Corporate Permissions

Academic Permissions

Related research

To cite this article:

Download citation

Information for

Open access

Opportunities

Help and information

Keep up to date

Your download is now in progress and you may close this window

Login or register to access this feature