Title :
A tunable wideband microstrip bandstop filter based on liquid crystal materials
Author :
Longzhu Cai ; Huan Xu ; Pivnenko, Mike ; Daping Chu
Author_Institution :
Electr. Eng. Div., Univ. of Cambridge, Cambridge, UK
Abstract :
A compact liquid crystal (LC) based tunable wideband microstrip bandstop filter (BSF) is presented in this paper. To realize a compact size and wide stopband bandwidth, a double-stub bending structure was designed. The BSF stopbands can be tuned by applying a voltage between 0-20 V to regulate the LC dielectric permittivity. A tunability >7% and 3dB bandwidth > 3 GHz and 2.5 GHz for the first and second stopbands respectively were achieved. The rejection level was higher than 41 dB. Such a LC based BSF device with a high tunability, wide stopband bandwidth, low driving voltage and compact size are useful in a wide range of applications.
Keywords :
LC circuits; UHF filters; band-stop filters; bending; liquid crystal devices; microstrip filters; microwave filters; permittivity; LC based BSF stopbands device; LC dielectric permittivity; compact liquid crystal materials; compact size; double-stub bending structure; frequency 2.5 GHz; frequency 3 GHz; low driving voltage; rejection level; tunable wideband microstrip band-stop filter; voltage 0 V to 20 V; wide stopband bandwidth; Dielectrics; Microstrip filters; Microwave filters; Permittivity; Transversal filters; Wideband;
Conference_Titel :
Communication Problem-Solving (ICCP), 2014 IEEE International Conference on
Print_ISBN :
978-1-4799-4246-6
DOI :
10.1109/ICCPS.2014.7062370
