Low-temperature cofired ceramic planar helical filter with single-sided transmission zeros

Author

Wu, Yafen ; Wenquan Che ; Kuo-Sheng Chin ; Kuang-Ching Chang ; Wenjie Feng

Author_Institution

Dept. of Commun. Eng., Nanjing Univ. of Sci. & Technol., Nanjing, China

Volume

50

Issue

19

fYear

2014

fDate

September 11 2014

Firstpage

1363

Lastpage

1365

Abstract

A planar low-temperature cofired ceramic helical bandpass filter with a compact size is presented. The proposed filter is constructed from short-circuited λ_g/4 helical resonators, while the size is reduced significantly by winding resonators vertically. Two single-sided transmission zeros can be created by the proposed mixed electric and magnetic coupling structure. A prototype with size of 6.2 × 4 mm² (0.049 × 0.032λ_g²) has been fabricated for demonstration. The measured fractional bandwidth is 5.9% at 0.845 GHz, and two transmission zeros are observed at 0.90 and 1.07 GHz.

Keywords

UHF filters; UHF resonators; band-pass filters; electromagnetic coupling; resonator filters; bandwidth 0.845 GHz; frequency 0.90 GHz; frequency 1.07 GHz; low-temperature cofired ceramic planar helical bandpass filter; magnetic coupling structure; mixed electric coupling structure; short-circuited λg/4 helical resonators; single-sided transmission zeros; winding resonators;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el.2014.2530

Filename

6898649