Design And Research Of Automotive Millimeter Wave Radar Array Antenna

In recent years,autonomous driving technology has developed rapidly,as an important component of the automotive autonomous driving field,the automotive millimeter wave radar has the characteristics of low cost and all-weather operation,and has received praise from many manufacturers.This article takes this as the background to carry out the design and research of the automotive millimeter wave radar microstrip antenna array.The main work is as follows:This article first designs a rectangular microstrip array antenna applied in the field of automotive millimeter wave radar.The 1×16 linear array composed of rectangular microstrip patches and adopts Taylor synthesis method to reduce the sidelobe level of the linear array.Subsequently,a one-eighth power divider with a power distribution that satisfies the Taylor distribution was designed for area array feeding to improve the H-plane pattern.From the design steps of linear array,power division network,and planar array,the final designed antenna is 8×16 rectangular microstrip array antenna.Simulation results show that the impedance bandwidth is about 1.6GHz,the gain at the center frequency of 76.5GHz reaches 26 d B,and the side lobe level is lower than-20 d B.Subsequently,a comb shaped microstrip array antenna was designed.This antenna still uses the previously designed one eighth power divider,1×16 line array consisting of microstrip stubs.The polarization method is horizontal polarization,with a linear array gain of 16.3d B.Using a power divider to ultimately form 8×16 plane array.Comparing the designed 8×16 rectangular microstrip antenna array with the 8×16 comb microstrip antenna array,it was found that the comb array can effectively reduce the size of the antenna while maintaining the same number of elements,and the overall performance is good,which is more conducive to radar integration in the later stage.Finally,a waveguide microstrip transition structure was designed to facilitate physical testing.The test results are in good agreement with the simulation results.The gain at the center frequency point of 76.5GHz is 22.8d B,the impedance bandwidth is about 2.5GHz,and the sidelobe level is lower than-18 d B.Finally,the common engineering problems of microstrip antenna simulation landing were studied and analyzed,and corresponding solutions were proposed.Firstly,a single-layer flat radome was designed,and the design elements of the radome were introduced.The vertical polarization antenna and the horizontal polarization antenna were respectively added with radomes.Both four port network analysis and simulation analysis have verified that horizontally polarized antennas have more advantages in the transmission rate of radomes.Therefore,if you want the radar to have a wider beam coverage range,it is more recommended to use horizontally polarized antennas;Subsequently,simulation analysis was conducted to investigate the significant impact of the size of the reference ground on the antenna pattern.An approach was proposed to utilize the stopband characteristics of EBG to limit electromagnetic waves within a certain range,effectively limiting the size of the reference ground and achieving good results.