Chung Youchung, Berhe Teklebrhan H
Information and Communication Engineering Department, Daegu University, Kyungsan 38453, Korea.
Sensors (Basel). 2021 Apr 4;21(7):2521. doi: 10.3390/s21072521.
In this paper, various locations of an Ultra High Frequency (UHF) Radio Frequency Identification (RFID) tag on automotive license plates have been considered based on the radiation pattern of the tag antenna. A small, 130 × 50 mm, passive loop antenna type UHF RFID tag for an automotive license plate was simulated with an EM simulation CST program. It was designed to have a larger back-lobe radiation pattern since the front side of the tag faces the back side of the plate holder to protect the tag antenna from bugs and dust when the automobile runs. The tag was attached to the side of a license plate holder with a dimension of 520 × 110 mm, the typical size of the standard license plate. The reflection coefficient of the tag antenna is -21 dB at 920 MHz, and the gain of the tag antenna is 6.29 dBi at the back-lobe. The reading range of the tag antenna with the plate holder, which was measured in an open field, is about 10.3 m, and the reading range of the tag installed on the bumper from the front of the vehicle is 9.4 m. The tag antenna is small enough to apply to a real automobile, and it is applicable because it uses the back-lobe pattern, so it does not require an extra device for protection from damage.
本文基于超高频（UHF）射频识别（RFID）标签天线的辐射方向图，考虑了汽车牌照上超高频RFID标签的不同位置。使用电磁仿真CST程序对一款尺寸为130×50mm的小型无源环形天线型汽车牌照UHF RFID标签进行了仿真。由于当汽车行驶时标签的正面朝向牌照架的背面，以保护标签天线免受虫子和灰尘的影响，所以该标签被设计为具有更大的后瓣辐射方向图。该标签被粘贴到尺寸为520×110mm的牌照架侧面，这是标准牌照的典型尺寸。标签天线在920MHz时的反射系数为-21dB，在后瓣处标签天线的增益为6.29dBi。在开阔场地测量的带有牌照架的标签天线的读取范围约为10.3m，安装在车辆保险杠上的标签从车辆前方的读取范围为9.4m。该标签天线足够小，可以应用于实际汽车，并且由于它使用后瓣方向图，所以无需额外的保护装置以防损坏，因此是适用的。
