Research On Liquid Water Antenna

With the development of wireless communication technology,more and more new antennas are being designed and applied to communication equipment.We refer to a new type of antenna in which water is designed as a liquid water antenna.The liquid water antennas designed in this paper can be roughly divided into two categories,one is a seawater antenna using seawater as a radiator,and the other is a distilled water medium antenna.In this paper,the seawater monopole antenna,seawater Yagi antenna,seawater corner reflector antenna,and distilled water medium antenna are studied.Based on the theory of metal antennas,the design scheme of liquid water antennas is proposed,where their gains,reconfigurability and bandwidth are mainly studied.It issues to accelerate the application and development of liquid water antennas in wireless communication systems.Therefore,six liquid water antennas are proposed in this paper.The specific work is as follows:The first chapter introduces the research background of liquid water antennas and the development status of seawater antennas,water medium resonator antennas,water medium patch antennas and water medium loaded antennas.The second chapter summarizes the basic theory and electrical parameters of the antenna,the related theories of water conductivity and dielectric constant.The third chapter studies the design method of seawater monopole antennas,and proposes and designs two kinds of seawater monopole antennas.The first type is a metal-loaded static seawater monopole antenna.The design scheme proposed in this chapter can use the seawater monopole antenna to load the metal without destroying the advantages of seawater antenna frequency reconfigurability,miniaturization and invisible.The method reduces the energy loss of the antenna and increases the antenna gain,which solves the problem that the gain of the seawater antenna is too low due to the low conductivity of the seawater.In this chapter,a dynamic seawater monopole antenna is also designed.We have proposed a static seawater monopole antenna connected in parallel with a short-circuited branch,and pumped seawater through this branch to achieve a dynamic seawater antenna design scheme.Electromagnetic simulation shows that the antenna has the characteristics of broadband and high gain.In order to further study the gain and reconfigurability of seawater antennas,the fourth chapter proposes and designs two kinds of seawater antennas.The first is a seawater Yagi antenna.We have proposed a design that uses multiple passive oscillators with adjustable heights to switch between the dipole and the reflective oscillator,making the antenna reconfigurable in frequency and pattern.The passive oscillator can increase the maximum gain of the antenna radiation direction.The second type is a seawater corner reflector antenna.We propose a design scheme in which the corner reflector is replaced by multiple seawater reflectors.The antenna lobe width can be adjusted by adjusting the number of reflectors,and the active and reflective oscillators can also be adjusted to make the antenna frequency reconfigurable.This paper not only studies the seawater antenna,but also the distilled water medium antenna.In fifth chapter,two wideband distilled water medium antennas are proposed.The first is a broadband Yagi antenna loaded with distilled water.The difference from the seawater Yagi antenna is that the active oscillator of the Yagi antenna designed in this chapter is a folded oscillator,so that the antenna has a better bandwidth.By adding distilled water to the directing oscillator,it is relatively easy to change the directing oscillator into a reflective oscillator,so that the antenna has the advantage of reconfigurable pattern.The second type designed in this chapter is a broadband water patch antenna.By combining the design theory of metal patch antennas,we propose a design scheme that uses two water patches and introduces multiple resonance points,significantly improving the antenna bandwidth.