Cheng Kaixuan, Lee Yee Hui, Qian Jiwei, Lee Daryl, Yusof Mohamed Lokman Mohd, Yucel Abdulkadir C
School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Ave., Singapore 639798, Singapore.
Centre for Urban Greenery and Ecology, National Parks Board, 1 Cluny Rd., Singapore 259569, Singapore.
Sensors (Basel). 2024 Jun 27;24(13):4170. doi: 10.3390/s24134170.
A dual-polarized compact Vivaldi antenna with high gain performance is proposed for tree radar applications. The proposed design introduces an array configuration consisting of two pairs of two Vivaldi elements to optimize the operating bandwidth and gain while providing dual-polarization capability. To enhance the gain of the proposed antenna over a certain frequency range of interest, directors and edge slots are incorporated into each Vivaldi element. To further enhance the overall antenna gain, a metal back reflector is used. The measurement results of the fabricated antenna show that the proposed antenna achieves a high gain of 5.5 to 14.8 dBi over broadband from 0.5 GHz to 3 GHz. Moreover, it achieves cross-polarization discrimination larger than 20 dB, ensuring high polarization purity. The fabricated antenna is used to detect and image the defects inside tree trunks. The results show that the proposed antenna yields a better-migrated image with a clear defect region compared to that obtained by a commercial Horn antenna.
本文提出了一种用于树木雷达应用的具有高增益性能的双极化紧凑型维瓦尔第天线。所提出的设计引入了一种由两对两个维瓦尔第元件组成的阵列结构，以优化工作带宽和增益，同时提供双极化能力。为了在所关注的特定频率范围内提高所提出天线的增益，在每个维瓦尔第元件中加入了导向器和边缘缝隙。为了进一步提高整体天线增益，使用了金属背反射器。所制作天线的测量结果表明，所提出的天线在0.5 GHz至3 GHz的宽带范围内实现了5.5至14.8 dBi的高增益。此外，它实现了大于20 dB的交叉极化鉴别，确保了高极化纯度。所制作的天线用于检测树干内部的缺陷并成像。结果表明，与商用喇叭天线相比，所提出的天线产生了具有清晰缺陷区域的更好的偏移图像。
