The Research Of Flexible And Reconfigurable Liquid Metal Antenna

With the development of wireless communication technology and the rapid growth of wireless communication application requirements in various fields,the requirements for antenna performance are becoming more and more complex and diverse.The coexistence of various communication methods makes the system need to install a variety of transmitting and receiving antennas,but the existence of multiple antennas will lead to a reduction in system space and mutual interference between different signals.At the same time,the external environment is constantly changing,and the antenna needs to be better integrated with the surface of the object,so reconfigurability and flexibility are important research directions for future antenna development.Compared with traditional solid materials,the properties of liquid metal make it very suitable for the design and manufacture of reconfigurable and flexible antennas.This thesis studies the characteristics of liquid metal and its driving technology,reconfigurable and flexible antenna technology,and designs two liquid metal reconfigurable antennas and one liquid metal flexible antenna.The main work of this thesis is as follows:(1)A pattern reconfigurable antenna with liquid metal is proposed.The antenna uses an ultra-wideband directional Vivaldi antenna as the basic structure,and uses liquid metal to design a parasitic structure.The liquid metal is driven by pressure to control the angle of the antenna's main beam.Studies have shown that the liquid metal parasitic structure can continuously tune the antenna beam angle in the range of-30°?30°,and has little effect on the antenna impedance matching.When the length of the liquid metal parasitic structure is changed,the beam direction of different frequency bands can be adjusted.(2)A multi-polarization reconfigurable antenna with liquid metal is proposed.The antenna is based on the circular patch antenna structure,and the surface current of the patch is changed by designing the movement of liquid metal to realize the reconfiguration of multiple polarization modes.The liquid metal driving method adopted in this design is continuous electrowetting,and the position of the liquid metal is adjusted by applying voltage on the electrodes,which realizes the change of multiple polarization modes.For linear polarization mode,the antenna can be continuously tuned between-90°?90° polarization direction,or it can be switched to circular polarization mode,and switch between left-hand circular polarization and right-hand circular polarization.(3)A liquid metal flexible antenna is proposed,which is designed with an Inverted F antenna as the basic antenna structure.In order to improve the stability of the working frequency of the antenna in the bending state,a rectangular bending structure is selected to improve the inverted F antenna to form a Meandered Inverted F Antenna.The liquid metal wrapping material uses PDMS,which has high elastic properties to meet the bending requirements of flexible antennas.Finally,the antenna was fabricated and tested to verify its bending performance and stability of operating frequency.