Research On Dual-frequency Antenna And Graphene Reconfigurable Antenna

The millimeter-wave(MMW)communication technology in the 45 GHz and 60 GHz band has advantages over the traditional wireless communication technology in terms of spectrum resources,transmission speed and data capacity.At present,the researches on these two frequency bands are mainly focusing on single-frequency antennas,and the designs of dual-frequency antennas are relatively less.Graphene is used in many antenna because of its superior physical properties compared to other materials.Graphene can achieve dynamic adjustment of the antenna by external bias voltage control.Therefore it can be applied in the reconfigurable antenna design of millimeter wave and terahertz band.This paper focuses on dual-frequency and graphene-based reconfigurable antenna.The main researches are as follows:A novel millimeter-wave dual-frequency microstrip antenna is designed to work at 45 GHz and 60 GHz by slotting the ground plate and attaching parasitic patches.Considering the inherent disadvantages of narrow frequency band and low gain of microstrip antenna,the bandwidth and gain can be effectively increased through lamination design.The influence of dielectric layers with different dielectric constants on the antenna is explored.Then,based on the dual-frequency microstrip antenna designed above and combined with the special electrical characteristics of graphene,a frequency reconfigurable microstrip antenna using graphene is designed to realize the multi-frequency band adjustment,which is different from the traditional single-frequency band hopping.The adjustable frequency band was broadband with a coverage of 60 GHz and a bandwidth of over 28%,and dual-frequency bands with a central frequency of 35 GHz and 58 GHz.The research on THz graphene-based reconfigurable antenna is carried out.The dipole antenna was used as the feed antenna to design the square shape and annular directional reconfigurable terahertz antenna,so as to realize the radiation beam change of the antenna in the terahertz frequency band.The effects of different chemical potentials on the performance of the antenna are analyzed.Finally,a reconfigurable antenna is designed with a loop antenna as the feed source,which can realize six-beam radiation scanning and has good performance within the working bandwidth.