Novel High-performance Dielectric Resonator Antennas

With the rapid development of wireless communication technology,human beings are about to enter the 5G era.As the pivotal device in the communication process,the novel antenna covered suitable frequency range with high performance will greatly promote the development of 5G communication.Novel antennas mean new material and new structure.New materials such as graphene can give new characteristics to the antenna,and the new structure can guarantee the excellent performance of the antenna.In this paper,graphene material is applied to the design of dielectric resonator antenna?DRA?.Furthermore,antenna based graphene can achieve the same performance as traditional metal antenna.On the other hand,its material characteristics such as ultra-high conductivity,thermal conductivity,corrosion resistance,and flexibility,give the antenna more functions.The specific works are as follows:Firstly,the study of graphene material as antenna feeder is carried out.A rectangular dielectric resonator antenna?RDRA?fed by offset tapered graphene microstrip lines are presented.The graphene films with conductivity up to1.1×10⁶S/m are used for feeding RDRA.Four feed forms have been discussed.The presented feed mechanism is able to couple electromagnetic energy in three different modes of the RDRA.The results show that an impedance bandwidth of 11.32%?3.25³.64GHz?is realized.At the center frequency,and a peak gain of 4.48dBi is obtained at the center frequency.The experiment shows that graphene films can be used to couple the RDRA,and the novel RDRA can achieve the same performance as the metal antenna.In addition,this single RARA is extended to 2×2 antenna array.The performance of array is good and the gain is increased to 9.8dBi.Secondly,the study on miniaturized frequency selective surface?FSS?is carried out.A novel stopband FSS made of high-conductivity graphene film is presented.The FSS is a“Hamburg”structure consisting of two-layer graphene films and one-layer dielectric substrate.The proposed improved Jerusalem cross FSS,compared with traditional cross FSS,can effectively reduce the size of unit cell by 88.9%.The FSS has a good blocking effect at 3⁴GHz.At the center frequency of 3.5GHz,the S₂₁reaches about-45dB.Finally,the proposed FSS is applied to the RDRA array.The array is made up of1×2 RDRA with dual-port slot-feed.The FSS composing of 2×10 unit cells along the E-plane,is placed in the middle of the two dielectric resonators.The results show that the mutual coupling is reduced by more than 7dB in average with the FSS,and the FSS has little effect on the return loss and radiation pattern of the antenna.The novel high-performance DRA and array proposed in this paper have the characteristics of simple structure,new material,small size,suitable bandwidth and good performance,which both work arond 3.5GHz.It provides ideas for the design of5G communication antenna in the future.