Design Of A Circularly Polarized Dielectric Resonator Antenna

In order to fit the development needs of modern wireless communication technology,dielectric resonator antennas(DRA),which have good qualities of minisize,low loss and broadband,have been widely studied and applied.Because the circularly polarized antennas have abilities to resist multipath reflection and rain or fog interference,and the polarization distortion,caused by the Faraday rotation effect of the ionized layer,could be eliminated by them.The paper Focuses on the circularly polarized dielectric resonator antennas,studies the realization of dual-band and broadband,as well as the realization of circular polarization based on the line-to-circular polarization conversion metasurface.The specific contents are as follows:1.A circularly polarized DRA with dual-band is designed.The antenna is fed by slot coupling.The microstrip line is coupled through two circular gaps of different sizes on the metal floor,excites the two resonant points of the antenna,so that it works in the dual band.Two unequal orthogonal branches are added at the oblique 45°on the gap,to excite the orthonetric modes inside the antenna,so as to stimulate the circular polarization performance.The model of the antenna is machined and measured.From the test result,we can see that the antenna exhibits good resonance characteristics.The antenna can work in 8.58 GHz-9.82 GHz and 12.36 GHz-13.50 GHz two bands,the relative bandwidth is 13.7% and 8.7% respectively.And in 9.53GHz-10.15 GHz and 12.15 GHz-13.18 GHz bands,the antenna achieve the axial ratio bandwidth of 6.89% and 7.92% respectively.In this band,antenna can achieve dual-band circular polarization radiation.2.A broadband circularly polarized dielectric resonator antenna is designed.The antenna adopts a hybrid structure,using different materials and shapes of ceramic materials nest each other,effectively expand the bandwidth of the antenna.The antenna adopts the method of slot coupling feed.Subtract oblique 45° unequal orthogonal slots on the metal floor,in order to excite the circularly polarized radiation of the antenna.The antenna is machined and measured.After testing,the antenna works in 11.21 GHz-13.9 GHz band,the relative bandwidth is 21.52%.In 11.21GHz-12.61 GHz band,the antenna can achieve the axial ratio bandwidth of 11.76%.In this band,antenna can achieve broadband circular polarization radiation.3.A dielectric resonator antenna with line-to-circular polarized conversion metasurface is devised.In line with the fundamental structure of the Jerusalem Cross,a unit of linear-to-circular polarization conversion surface is designed.The simulation results indicate that the unit could covert linear polarization to circular polarization within the scope of 20.17 GHz to 22.24 GHz.After the periodic arrangement of the surface units,it is placed on the upper surface of the linearly polarized dielectric resonator antenna at an oblique 45°.The results indicate that the the antenna works in20.61 GHz-22.44 GHz band,the relative bandwidth is 8.71%.The axial ratio bandwidth is 20.49 GHz-21.14 GHz,the relative bandwidth is 3.10%.In this band,it could achieve the linear-to-circular polarization conversion.