Tunable microstrip patch antenna based on liquid crystals

In this project a novel design of a compact rectangular microstrip patch antenna using Liquid Crystals Substrates (LCs) for microwave applications is presented. To benefit from liquid crystal anisotropy and thus obtain frequency agility, a low bias voltage of about 10V is applied. This technique is used to 4 LCs with DC voltage satisfies a minimal return loss of -52.47dB with a bandwidth of 60MHz for operating frequency of 2.53GHz. The variation of the simulation resonance frequency (ΔFr) obtained after applying a continuous voltage is 530MHz corresponding to an important frequency agility of 26.5%. This method based on LCs can be used to cover several frequency bands, overcome the problem of narrow bandwidth of antenna, increase the peak gain and achieved a good return loss. The design and simulation of antenna is done by using Ansoft HFSS.13. The simulated results are compared with experimental data, and good agreement is obtained.