Research on Evaluation Index of Automotive Antenna Testing

Abstract

Mounted locations and the ground plane structure have remarkable influences on the performance of roof-mounted automotive antennas. To distinguish this influence in radiation, figure of merits (FoMs), including total radiated power (TRP), near-horizontal part radiated power (NHPRP), and cumulative distribution function (CDF), are studied in this paper. It is proved that TRPs are almost the same with different mounting configurations. Because the radiation toward the horizon is a critical performance metric for automotive antennas, NHPRP is analyzed within certain degrees near the horizon. Even though a bigger deviation has been observed in NHPRP, the discrimination between different mounted scenarios is still not enough. Different from TPR and NHPRP, which are efficiency-based FoMs, CDF combines the gain values and the pattern shape together, achieving a comprehensive and intuitive insight into the antenna performance. It is more predictive and distinguishable in terms of the radiation pattern than NHPRP and TRP. Therefore, CDF can be utilized as a good supplement to existing metrics and can better distinguish the radiation performance of different antenna mounting configurations.