Design of a six-pole tunable band-pass filter with constant absolute bandwidth
- Resource Type
- Conference
- Authors
- Huang, Xiao-Guo; Jin-Qi Zhang; Yi-Qun Lin; Xiang, Qian-Yin
- Source
- 2016 Progress in Electromagnetic Research Symposium (PIERS) Progress in Electromagnetic Research Symposium (PIERS). :3507-3510 Aug, 2016
- Subject
- Engineered Materials, Dielectrics and Plasmas
Fields, Waves and Electromagnetics
Geoscience
Photonics and Electrooptics
Bandwidth
Microstrip
Couplings
Inverters
Band-pass filters
Varactors
Frequency measurement
- Language
This paper presents the design and implementation of a tunable bandpass filter with constant absolute bandwidth. Two types of coupled microstrip lines in the anti-parallel and pro-parallel formats with varactor-loaded ⋋/2 resonators are investigated to demonstrate its advanced capacity in control of the bandwidth variation. In this design, two adjacent resonators are coupled with each other through a short-circuited transmission line as the K inverter. To verify the proposed approach, a compact six-pole tunable bandpass filter based on alternative J/K inverters and ⋋/2 resonators is designed, and the measured results show a tuning range from 1.9 to 2.3 GHz with a bandwidth of 580 ± 10 MHz.