Related Experiment Video
Updated: Feb 25, 2026

Simulation, Fabrication and Characterization of THz Metamaterial Absorbers
Published on: December 27, 2012
Improving the Pass-Band Return Loss in Liquid Crystal Dual-Mode Bandpass Filters by Microstrip Patch Reshaping
Javier Torrecilla1, Virginia Urruchi2, José Manuel Sánchez-Pena3
1Departamento de Tecnología Electrónica, Universidad Carlos III de Madrid, C.\Butarque n° 15, Leganés 28911, Spain. jtorreci@ing.uc3m.es.
Abstract:
In this paper, the design and experimental characterization of a tunable microstrip bandpass filter based on liquid crystal technology are presented. A reshaped microstrip dual-mode filter structure has been used in order to improve the device performance. Specifically, the aim is to increase the pass-band return loss of the filter by narrowing the filter bandwidth. Simulations confirm the improvement of using this new structure, achieving a pass-band return loss increase of 1.5 dB at least. Because of the anisotropic properties of LC molecules, a filter central frequency shift from 4.688 GHz to 5.045 GHz, which means a relative tuning range of 7.3%, is measured when an external AC voltage from 0 Vrms to 15 Vrms is applied to the device.
Related Concept Videos
Passive Filters
Low-Pass Filters
Low-pass filters are designed to transmit signals with frequencies lower than the cutoff frequency, ωc, and attenuate those above it. The cutoff...
Active Filters
Characteristics of Series Resonant Circuit
Parallel Resonance
Bandpass Sampling
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2....

