Preliminary Study On Vehicle Antenna Performance And Typical Test Site Under Vehicle Condition

Vehicle infrastructure cooperative is an important development direction of intelligent connected vehicle and C-V2 X,and the vehicle antenna is the key equipment for information interaction in this system.The performance evaluation of vehicle antennas is a hot topic in current research.In this paper,with the help of theoretical derivation,simulation analysis,and actual test verification,a preliminary study on the performance of the vehicle antenna and the typical test site is done under the whole vehicle conditionThe performance of the vehicle antenna is studied under the condition of the whole vehicle.By comparing the simulation results of the vehicle antenna single and the antenna under the whole vehicle condition,it is found that the vehicle antenna pattern has split lobes under the whole vehicle condition,the beam direction changes,the HPBW becomes narrower,and the EIRP in different directions has obvious change.Therefore,when evaluated the performance of the vehicle antenna,it must be tested under the whole vehicle condition.By improving the sampling accuracy,not only can the accurate results of the EIRP of the vehicle antenna in each direction be obtained,but the measurement area should be adjusted appropriately.In addition,by comparing the simulation data,it is found that the antenna coverage has changed significantly when the V2 X antenna is installed in different positions of the vehicle body,and the results of TRP and EIRP have also changed greatly in different directions.For vehicle V2 X antennas,according to the usage scenarios,the layout needs to be optimized so that the vehicle maintains a stable connection with the C-V2 X network during driving.The typical test site for vehicle antenna testing is studied.The radiation characteristics of the vehicle communication antenna when the antenna is installed on the roof of the vehicle under the condition of the whole vehicle are analyzed by simulation in free space,asphalt road,cement road,soil road and metal plate.It is found that the coverage of the vehicle antenna is relatively close,and there is no obvious difference between TRP and EIRP in different directions.Therefore,the vehicle communication antenna installed on the roof of vehicle can be tested in an anechoic chamber or an open area.By comparing the simulation results of TRP,it is found that when the vehicle communication antenna is placed on a metal plate with an area of 1 square meter the TRP is relatively close to the antenna under the whole vehicle condition.This scenario can be used as a simplified solution for the entire vehicle when the antenna is optimized.Relying on the spherical near-field test system of the CATARC Intelligent Networked Automotive Laboratory,the actual test of the vehicle communication antenna was carried out.The measured data and the simulation results were relatively consistent,which verified the correctness of the simulation analysis.