Research On 5G Millimeter-Wave Circularly Polarized Antenna Based On ISGW

With the rapid development of 5G communication,the study of base station antenna design using circular polarization technology has a huge role in promoting the construction and development of base stations in the future.The circularly polarized antenna proposed at present has disadvantages such as high loss,low gain,narrow bandwidth,high profile,poor isolation,and small power capacity of the microstrip antenna that does not form an array.The integrated substrate gap waveguide(ISGW)is a waveguide that can improve the performance of the antenna.Using this waveguide structure in combination with other technologies can improve the performance of the base station antenna.Therefore,this paper conducts related research on 5G millimeter-wave circularly polarized antennas based on ISGW technology.The main research work is as follows:(1)Gain is an important characteristic of an antenna,but the performance of having more antenna gains is not enough to meet the needs of current base station design.Aiming at the problem of low antenna gain,this paper proposes a 5G circularly polarized F-b antenna based on ISGW,which has high gain.A rectangular metal patch with cut corners is placed above the 3-layer ISGW to obtain two degenerate modes,thereby radiating circularly polarized electromagnetic waves.By adding a partial reflective surface above the circularly polarized antenna,an F-b resonant cavity is formed,which improves the gain and the matching.The simulation results can be obtained: the working frequency band of this antenna is from 23.84 to 27.72 GHz,the maximum gain is about 12.63 d Bic,and the relative working bandwidth(|S11|<-10 d B)is about 17.3%.(2)Although the above-mentioned circularly polarized antenna has high gain,its bandwidth is still relatively narrow,and it does not have the characteristics of high spectrum utilization efficiency and low power loss of broadband antenna.In view of the above problems,a broadband circularly polarized antenna based on ISGW is designed.The bandwidth expansion is realized by adding parasitic cross patches above the rectangular slot.The simulation results can be obtained: the operating frequency band of this antenna is from 23.4 to 30.2 GHz,the relative return loss bandwidth is 32.5%,and the maximum gain is 7.1 d Bic.(3)Since the frequency bandwidth and gain are both important performances of the antenna,in order to achieve these two indicators,a 1×2 MIMO(Multiple-Input MultipleOutput)circularly polarized antenna based on ISGW is proposed and designed.Taking circular polarization and MIMO antenna theory as the basic principle,combined with the current diagram,electric field diagram,pattern and related parameters(such as S parameter,gain,axial ratio bandwidth)of the 1×2 MIMO circular polarization antenna designed in this chapter(Axis Ratio bandwidth),Envelope Correlation Coefficient(ECC)),by analyzing the above parameters,it can be known that the working frequency band of this antenna is from 23.92 to 31.61 GHz,with 9.2% of the 3d B Axial Ratio Bandwidth,the maximum gain is 8.69 d Bic,the relative echo The loss bandwidth is29.6%.Through the comparison of processing and testing,it can be seen that the antenna performance is stable and has application value.By comparing the relevant literature that has been published in recent years,it can be found that this paper has a better structure and is more suitable for the currently vigorously developed 5G millimeter wave frequency band.