@ARTICLE{Torrecilla_J._Liquid_2015, author={Torrecilla, J. and Marcos, C. and Urruchi, V. and Sánchez-Pena, J.M. and Chojnowska, O.}, volume={vol. 23}, number={No 2}, journal={Opto-Electronics Review}, pages={121-125}, howpublished={online}, year={2015}, publisher={Polish Academy of Sciences (under the auspices of the Committee on Electronics and Telecommunication) and Association of Polish Electrical Engineers in cooperation with Military University of Technology}, abstract={Over the last twenty years, there has been a growing interest in the design of tunable devices at microwave frequencies by us- ing liquid crystals technology. In particular, the use of liquid crystals with high dielectric anisotropy allows manufacturing voltage-controlled devices to operate in a wide frequency range. In this work the frequency response of a liquid crystal band-pass filter with dual-mode microstrip structure has been studied in depth by using a simulation software tool. A reshap- ing of a conventional dual-mode square patch resonator bandpass filter with a square notch, studied in the literature, has been proposed with the goal of improving the filter performance. The main features achieved are a significant increase in the return loss of the filter and a narrowing of a 3-dB bandwidth. Specifically, a reduction in the filter bandwidth from 800 MHz to 600 MHz, which leads to a return loss increase from 6 dB to 12.5 dB, has been achieved. The filter centre frequency can be tuned from 4.54 GHz to 5.19 GHz.}, type={Article}, title={Liquid crystal dual-mode band-pass filter with improved performance}, URL={http://journals.pan.pl/Content/116130/PDF-MASTER/pan_doi_blank.pdf}, keywords={dual-mode filter, inverted microstrip structure, liquid crystal, tunable filter}, }