Integrated Design Of Millimeter-Wave Broadband Antennas And Radomes

The fifth-generation(5^thG)mobile communication and future mobile communication will make full use of the abundant spectrum resources in millimeter wave（MMW）band to achieve broadband,high transmission rate and high throughput communication.Hence,the cooperative broadband design of both MMW antenna and MMW radome is of great significance.First,the design method with features of low cost and low complexity is an important prerequisite for the large-scale application of MMW wideband antennas.Secondly,the broadband design method and integrated design analysis of radomes suitable for MMW antennas are also important during the development of the entire MMW antenna systems.Therefore,this thesis focuses on the two topics,i.e.,MMW low-cost,wideband antenna,and high-transmission,low-loss radome.The design and optimization for either antenna or radome have been studied independently,and then the integrated design of antenna and radome is carried out to analyze the integration performance,which is verified with either simualtions or experiments.The main research contents and outcomes of the thesis are as follows:（1）A low-cost wideband substrate integrated waveguide（SIW）series fed 45°-inclined slot antenna and array are proposed and developed,and the mechanism of improving bandwidth and gain by increasing the number of slots is analyzed.In addition,based on the inherent 45°polarization characteristic of the proposed inclined slot antenna,a±45°dual polarization MIMO antenna pair with high isolation of wide band is been developed.The measured bandwidth of quadruple inclined-slot antenna is 23.67%,and its measured maximum gain is 7.69 dBi at46GHz.The measured bandwidth of the SIW series fed quadruple inclined-slot eight-element array antenna is 18.2%,and its measured maximum gain is 17.33 dBi at 47GHz.（2）Based on the equivalent analytical model of multilayer dielectric structure under normal incident electromagnetic wave,the analysis and optimization design of homogeneous layered-structured radome based on single dielectric material is studied for MMW band.Based on the proposed concept of homogeneous layer-structured radome,three types of radomes are optimized in 28 GHz band.Through full-wave simulation,the optimized radomes can achieve a relative bandwidth of 80%in terms of the reflection coefficient≤-15 dB at normal incidence,and achieve a joint relative bandwidth of 43.75%for both TE modes（incident angle≤30°）and TM modes（incident angle≤60°）in terms of the reflection coefficient≤-15 dB.The transmission loss is less than 0.3 dB under either normal or oblique incidence,proving that the proposed radomes have wide band,low reflection and low loss properties.（3）Based on the Q-band fixed-beam wideband antenna and Ka-band beam-scanning wideband antenna,the integrated design and performance analysis of MMW broadband antenna and radome are studied.For the Q-band SIW series fed quadruple inclined-slot eight-element array antenna,the full-wave simulations show that both the S₁₁ curve and radiation pattern of the antenna have no obvious change with/without the radome,and the gain decreases by 0.04dB only.For the Ka band multi-beam patch antenna array,the simulations show that when the beam is scanned in the range of 0°to 40°,both the S₁₁ curve and radiation pattern of the antenna are in good agreement with/without the radome,and the gain decrease is less than 1 dB.The MMW wideband SIW series fed inclined-slot antenna,array and broadband radome optimization design proposed in the thesis have the advantages of low cost,low complexity and universality.It can provide a universal engineering design method for 5G and future MMW communication system development.