Design Of S-Band Reconfigurable Antenna Based On Liquid Metal Materials

Reconfigurable antenna can be applied to many scenarios,which endows new characteristics of antenna development.It is one of the core evolution goals of antenna research in the future.Traditional antenna is difficult to realize reconfiguration because of its own structural properties.The emergence of new materials brings dawn to the design of reconfigurable antenna.New materials have many novelties different from traditional antenna materials.Material new attributes provide a promising research space for interdisciplinary disciplines.Liquid metal,as a new alloy material,combines with antenna and brings new ideas for antenna design.In this paper,a pattern reconfigurable antenna based on liquid metal material is designed.The material of the antenna is liquid metal instead of traditional conductor.While retaining the role of traditional conductor and ensuring good conductivity of the antenna structure,the antenna has the advantages of liquid metal deformation and motion.The theoretical design of the antenna is based on the principle of self-shifting.The self-shifting theory is verified by the deformation of the dipole made of liquid metal material,and the phase difference of the surface current of the dipole is obtained.Taking the theory of antenna array as the core of antenna pattern reconfigurable design,the related theory of antenna array is analyzed,and the parameters related to the deflection angle of main lobe are obtained,that is,the distance between the elements and the phase difference between the elements.Under the condition of guaranteeing the standing wave coefficient of the antenna,the phase difference of the antenna array is provided by the deformation of the dipole,and the distance between the elements is reduced,so that the scanning of the main lobe with the largest angle can be realized.The theory of Yagi antenna provides guidance for the optimization of antenna pattern.In view of the problems existing in antenna radiation pattern,such as nearly omnidirectional,low gain and small maximum deflection angle of main lobe,the gain of main lobe of antenna is increased by 100%by loading director and reflector.The regular and orderly flow of the director and reflector leads to the increase of the maximum deflection angle of the main lobe,which is 200%higher than that before the introduction.The theory of electromagnetic band gap provides guarantee for real-time scanning of antenna beam.The structure of electromagnetic band gap unit comes from references.The reduction of element spacing brings serious coupling between antenna elements.The standing wave coefficient of antenna does not meet the requirement of less than two in the process of beam reconfiguration.The introduction of electromagnetic band gap structure reduces the coupling between antenna elements,so that the standing wave coefficient and the electrical parameters of antenna array can meet the real-time Reconfigurable requirements.The antenna operates at 2.4 GHz WiFi frequency band and the element spacing is0.48?₀.The beam reconfiguration can be realized within±21 degrees.The elements,the director and the reflector are all composed of liquid metal materials,but the control modes are different.The ECC control method is used for the element,and the air pump is used for the director and the reflector.In this paper,the direction of stretching and compression of each element length and the moving direction of the director and reflector are given.In order to explain the reconfigurable process of the antenna in detail,four antenna states in the reconfigurable process are selected.Four antenna parameters are given.In the real-time reconfigurable process,the antenna VSWR is less than 2,and the antenna gain is greater than 7dBi.All modeling and simulation optimization work in this paper is carried out in CST Microwave Studio^?electromagnetic simulation software.The characteristics of liquid metal are tested by Agilent N5227A vector network analyzer.Using the method of substitution experiment,the antenna objects of different states in the process of antenna reconfiguration are fabricated.The antennas in different states show that the simulation and experimental results have achieved good conformity,which verifies the feasibility of the project design.