K-band Liquid-crystal-Based Frequency Reconfigurable Conformal Array Antenna

In this paper, a frequency reconfigurable conformal array antenna based on liquid crystal material is proposed. Firstly, based on the electric tuning principle of liquid crystal material and the miniaturization technology of microstrip antenna, a miniaturized frequency reconfigurable antenna unit with coupling feeding mode is designed. The size of the antenna units is only 0.14λ*0.14λ by reducing the radiating patch through the fractal technology and the slot coupling feeding structure is used to increase the bandwidth and reduce the influence of the feeding line on the radiation patch. Finally, the four antenna elements are formed into a conformal array, and the frequency of the conformal array antenna can be reconstructed by adjusting the dielectric constant of the liquid crystal. Through Simulation analysis, When the dielectric constant of liquid crystal changes from 2.8 to 3.4, the resonant frequency of the conformal array antenna changes from 18.82 GHz to 19.96 GHz; and the frequency tuning range is 1.14 GHz. The reflection coefficient of the antenna in the frequency variation range is less than -20dB, and the peak gain is 6dBi.