Design and evaluation of multi-resonant unit cells based on liquid crystals for reconfigurable reflectarrays
- 1 January 2012
- journal article
- Published by Institution of Engineering and Technology (IET) in IET Microwaves, Antennas & Propagation
- Vol. 6 (3), 348-354
- https://doi.org/10.1049/iet-map.2011.0234
Abstract
A multi-resonant unit-cell based on liquid crystals is proposed for reconfigurable reflectarray antennas. The proposed reflectarray element is made up of three parallel dipoles in the same cell and a tunable liquid crystal as substrate. The performance of the multi-resonant unit cell is compared with that of a single-resonant element in a frequency band from 30 to 40 GHz, showing a significant improvement in bandwidth, range of phase and losses. For a commercial liquid crystal, the proposed element provides a phase range greater than 360° within a 7.4% bandwidth and losses lower than 4.7 dB. These results represent a significant improvement with respect to the single-resonant unit cell based on the same liquid crystal. Finally, the proposed multi-resonant element is validated by measuring the phase response and losses in an X-band waveguide simulator.Keywords
This publication has 18 references indexed in Scilit:
- Design and Measurement of Reconfigurable Millimeter Wave Reflectarray Cells With Nematic Liquid CrystalIEEE Transactions on Antennas and Propagation, 2008
- Monolithic MEMS-Based Reflectarray Cell Digitally Reconfigurable Over a 360 $^{\circ }$ Phase RangeIEEE Antennas and Wireless Propagation Letters, 2008
- Reflectarray AntennasPublished by Wiley ,2007
- Liquid-crystal-based reflectarray antenna with electronically switchable monopulse patternsElectronics Letters, 2007
- Electronically reconfigurable reflectarrays with nematic liquid crystalsElectronics Letters, 2006
- Broad-band microwave characterization of liquid crystals using a temperature-controlled coaxial transmission lineIEEE Transactions on Microwave Theory and Techniques, 2005
- Realizing an electronically tunable reflectarray using varactor diode-tuned elementsIEEE Microwave and Wireless Components Letters, 2005
- Experimental investigation of a varactor loaded reflectarray antennaPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2003
- Optical Constants of Two Typical Liquid Crystals 5CB and PCH5 in the THz Frequency RangeJournal of Biological Physics, 2003
- The Physics of Liquid CrystalsPhysics Today, 1995