Title :
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
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;
Journal_Title :
Microwave and Wireless Components Letters, IEEE
DOI :
10.1109/LMWC.2014.2330694
