Superconducting Varactor Tunable Filter With Constant Bandwidth Using Coupling Line

Author

Guannan Suo ; Xubo Guo ; Bisong Cao ; Bin Wei ; Xiaoping Zhang ; Tianning Zheng ; Guoyong Zhang

Author_Institution

Dept. of Phys., Tsinghua Univ., Beijing, China

Volume

24

Issue

9

fYear

2014

fDate

Sept. 2014

Firstpage

628

Lastpage

630

Abstract

This letter presents a superconducting tunable filter with a constant bandwidth using semiconductor varactors. A coupling line is introduced to adjust the inter-resonator coupling to meet the requirement of constant bandwidth. The external couplings are designed to remain a good passband shape with the tunable frequency. With the proposed method, a superconducting tunable filter with constant bandwidth is successfully implemented. The measured results of the filter agree well with the simulated ones. It shows a frequency tuning range of 11% from 924.5 MHz to 1030.8 MHz, a 1 dB bandwidth of 23.8 ± 0.3 MHz, and an insertion loss of 0.16 to 1.41 dB.

Keywords

UHF filters; resonator filters; superconducting filters; varactors; constant bandwidth; coupling line; external couplings; frequency 924.5 MHz to 1030.8 MHz; interresonator coupling; loss 0.16 dB to 1.41 dB; passband shape; semiconductor varactors; superconducting varactor tunable filter; tunable frequency; Bandwidth; Couplings; High-temperature superconductors; Q-factor; Resonator filters; Superconducting filters; Varactors; Bandpass filter (BPF); constant bandwidth; superconducting; tunable; varactor;

fLanguage

English

Journal_Title

Microwave and Wireless Components Letters, IEEE

Publisher

ieee

ISSN

1531-1309

Type

jour

DOI

10.1109/LMWC.2014.2330694

Filename

6843362