Compact tunable bandpass filter with wide tuning range and enhanced stopband characteristics

Author

Zhao, B.L. ; He, Z.T. ; Wei, X.B. ; Shi, Y.

Author_Institution

State Key Lab. of Electron. Thin Films & Integrated Devices, Univ. of Electron. Sci. & Technol. of China, Chengdu, China

Volume

49

Issue

16

fYear

2013

fDate

Aug. 1 2013

Firstpage

1007

Lastpage

1008

Abstract

A compact tunable bandpass filter (BPF) with wide tuning range and enhanced stopband characteristics based on low-temperature co-fired ceramic technique is proposed. The wide tuning range is realised by properly introducing an axial coupling structure. Three transmission zeros are obtained near the passband for enhanced frequency selectivity by introducing mixed electric/magnetic (E/M) coupling between the source/load and the taped inductor. Back-to-back varactor diodes are adopted to improve linearity characteristics. A tunable BPF with a 120% tuning range from 370 to 850 MHz has been designed and fabricated to verify the proposed design concept. The measured results are in good agreement with the electromagnetic simulation. The circuit occupies only 4.0 × 3.0 × 1.6 mm³.

Keywords

band-pass filters; band-stop filters; ceramics; poles and zeros; axial coupling structure; back-to-back varactor diodes; electric/magnetic coupling; electromagnetic simulation; frequency 370 MHz to 850 MHz; low-temperature co-fired ceramic technique; stopband filters; transmission zeros; tunable bandpass filter;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el.2013.1186

Filename

6571498