Investigation On Millimeter-wave Dual-band Shared-aperture Dual-polarized Planar Array

Shared-aperture antenna is widely concerned for its characteristics of high space utilization,multi-band and multi-polarization,and has broad application prospects in modern wireless communication systems.In the application background of K/Ka band low orbit satellite communication,based on Archimedes spiral and L-shaped patch structure,this paper studies the millimeter-wave dual-band shared-aperture multi-polarization planar array in depth.The main work and achievements are as follows:Firstly,based on the stacked Archimedes spiral structure,a novel spiral K/Ka band sharedaperture dual circular polarization antenna element is proposed and designed.Through a single feed port,the two nested spiral arms work in different bands and achieve orthogonal circular polarization.The simulation results show that the antenna element is left-hand circular polarization(LHCP)in K band,and the 3d B relative axial ratio bandwidth is 12.03%(17.34-19.56GHz).In Ka band,it is right-hand circular polarization(RHCP),and the 3d B relative axial ratio bandwidth is 9.21%(27.45-30.1GHz).The antenna element was extended to 8×8 antenna array through a broadband substrate integrated coaxial line(SICL)feed network,and the processing and measuring analysis were carried out.The measured results show that the antenna array has a 3d B relative axial ratio bandwidth of 11.59%(18.7-21GHz)and 9.93%(26.8-29.6GHz),the circular polarization performance is good.Secondly,a new L-shaped K/Ka band shared-aperture dual circular polarization antenna element is proposed and designed by using L-shaped radiation patch structure.Two independent feed ports feed two staggered L-shaped patches operating in different bands,respectively,to achieve orthogonal circular polarization,and reduce the coupling between ports through the split-ring resonator(SRR)structure.The simulation results show that the antenna element is right-hand circular polarization(RHCP)in K band,and the 3d B relative axial ratio bandwidth is 7.98%(18.29-19.81GHz).In Ka band,it is left-hand circular polarization(LHCP),and the3 d B relative axial bandwidth is 10.34%(26.88-29.81GHz).On this basis,the 4×4 antenna array is extended.For the two feeding ports distributed in different layers,the coplanar waveguide with ground(GCPW)feed network working in K band and the substrate integrated coaxial line(SICL)feed network working in Ka band are designed respectively.The integrated antenna array is processed and measured.The measured results show that the antenna array has a 3d B relative axial ratio bandwidth of 11.76%(18-20.25GHz)and 8.22%(28-30.4GHz),which verifies the performance of the shared-aperture antenna array.