Investigation And Analysis On Reconfigurable Antenna Based On Liquid Crystal

With an increasing number of wireless communication customers and a more complicated condition of communication,reconfigurable antenna is becoming more and more important.On the other hand,the antenna that operates at high frequency is of much significance because the commonly used frequency band is scarce.The traditional reconfigurable antenna has some problems,such as the reconfigurability is not continuous and the performances are bad at high frequency.So it is of great significance to design a reconfigurable antenna which is of continuous reconfigurability and suitable for high frequency.In this paper,we mainly discuss the design method and key parameters of the reconfigurable antenna with characteristics of high operating frequency and continuous reconfigurability.The candidate's major contributions are outlined as follows: First of all,the principle and related characteristics of liquid crystal(LC)suitable for applications in high frequency are summarized,and simulations are made to analyze the orientations of liquid crystal molecules with different bias voltage,and then the relations between permittivity and bias voltage are concluded.Secondly,the principle of frequency reconfigurable patch antenna using LC is analyzed,and a traditional patch antenna is introduced with the simulations of frequency reconfigurable,and then the shortages of this traditional antenna are discussed.Based on the traditional antenna,a novel antenna is presented with the same size.The novel antenna can not only reconfigure its operating frequency,but also achieve better performances both in S parameters and radiation pattern.Thirdly,the probability of adjusting the frequency reconfigurable range is analyzed,and then simulations are made to validate it.Finally,a kind of mender line phase shifter using LC is presented,and then a radiation pattern reconfigurable antenna array using the mentioned phase shifter is presented.This antenna array can reconfigure its radiation pattern by controlling the phase of each radiating element.