A Liquid-crystal-based Dual-band Reconfigurable Microstrip Antenna for Ka-band

A reconfigurable microstrip antenna with continuously adjustable frequency based on liquid crystal is proposed in this paper. The liquid crystal is placed below the patch. Based on the electric tuning principle of liquid crystal, the dielectric constant of the antenna is changed by changing the bias voltage applied at both ends of the liquid crystal, so as to change the resonant frequency of the antenna. The aperture coupling feed is used to reduce the interference of the microstrip line radiation to the antenna, and the parasitic patch is placed above the radiation patch to introduce a new resonance point near the original frequency point. The proposed antenna could be used for Ka-band, the resonant frequency agility from 27.9/31.42 GHz to 28.04/30.34 GHz, and the high frequency tuning quantity is 1.08 GHz. The return loss of the antenna is less than - 20 dB. A maximum gain of 7.41 dB is obtained. The simulation results show that the antenna provides a new idea for the design of frequency reconfigurable antenna.