Research On Responsive Terahertz Microstrip Array Antenna Based On Electrically Controlled Liquid Crystal

Nowadays,the spectrum resource is increasingly scarce,but terahertz wave is still in the stage of not being fully developed and utilized,so terahertz technology has become a breakthrough in the development of science and technology in countries around the world.The unique characteristics of terahertz technology,such as high penetration,low energy,wide frequency band and high signal-to-noise ratio,make it has a broad application prospect in many fields,such as electronic warfare,medical imaging,communication technology,terahertz radar and so on.Terahertz phase-controlled array antenna,as an important component in terahertz system,plays a key role in the development of terahertz technology.The terahertz functional device,which combine liquid crystal with artificial electromagnetic microstructure,have an electronically controlled tuning characteristic,which is an effective means for the phase adjustment of the terahertz array antenna.This paper focuses on the research of responsive liquid crystal terahertz functional devices and the reflective array antenna of electronically controlled scanning to develop new technologies of the terahertz phase-controlled array antenna.Aiming at the problem of the slow response time of traditional liquid crystal in the terahertz frequency band,this paper introduces polymer network into the liquid crystal,using the anchoring property of the polymer network to shorten the free relaxation time of the liquid crystal molecules,thereby shortening the response time of the liquid crystal material in the terahertz frequency band.In order to quantitatively measure the characteristic of polymer network liquid crystal materials,a tunable absorber which can be used to test the response time has been designed.In the comparative experiments,the polymer network liquid crystal was used to replace the traditional nematic liquid crystal.the experimental results show that the response time is shortened by an order of magnitude,which lays a theoretical foundation for the responsive liquid crystal THz functional device.In this paper,a reflective phase shifter with double resonance structure based on liquid crystal is developed.By analyzing the influence of structural geometrical parameters on the adjustment range and linearity of the phase-shifting,a phase-shifting unit with double resonance structure is designed.The phase shifter samples were manufactured by Uv wet lithography and tested,which showed that the phase shifting range is 350° at around 100 GHz.Finally,a reflective array antenna consisting of 39×39 array elements is designed by using the designed phase shifting unit.Simulation results verify that the scanning capacity of the antenna can achieve-35° to 35°.