Wu Chin-Hsien, Huang Tsun-Che, Ng Mou Kehn Malcolm
Wistron NeWeb Corporation, Hsinchu 300092, Taiwan.
Institute of Communications Engineering, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan.
Sensors (Basel). 2025 May 22;25(11):3262. doi: 10.3390/s25113262.
Millimeter-wave antennas have become more important recently due to the diversity of applications in 5G and upcoming 6G technologies, of which automotive systems constitute a significant part. Two crucial indices, detection range and angular resolution, are used to distinguish the performance of the automotive antenna. Strong gains and narrow beamwidths of highly directive radiation beams afford longer detection range and finer spatial selectivity. Although conventionally used, patch antennas suffer from intrinsic path losses that are much higher when compared to the waveguide antenna. Designed at 77 GHz, presented in this article is an 8-element slot array on the narrow side wall of a rectangular waveguide, thus being readily extendable to planar arrays by adding others alongside while maintaining the element spacing requirement for grating lobe avoidance. Comprising tilted Z-shaped slots for higher gain while keeping constrained within the narrow wall, adjacent ones separated by half the guided wavelength are inclined with reversed tilt angles for cross-polar cancelation. An open-ended external waveguide is placed over each slot for polarization purification. Equivalent circuit models of slotted waveguides aid the design. An approach for sidelobe suppression using the Chebyshev distribution is adopted. Four types of arrays are proposed, all of which show potential for different demands and applications in automotive radar. Prototypes based on designs by simulations were fabricated and measured.
毫米波天线近来变得越发重要，这归因于其在5G及即将到来的6G技术中的多种应用，其中汽车系统是重要组成部分。检测范围和角分辨率这两个关键指标用于区分汽车天线的性能。高指向性辐射波束的高增益和窄波束宽度可实现更长的检测范围和更精细的空间选择性。尽管贴片天线是传统上使用的，但与波导天线相比，它存在固有路径损耗，且损耗要高得多。本文介绍了一种设计在77GHz的8元缝隙阵列，它位于矩形波导的窄侧壁上，因此通过在旁边添加其他阵列并保持避免栅瓣所需的单元间距要求，很容易扩展为平面阵列。该阵列由倾斜的Z形缝隙组成，以实现更高的增益，同时限制在窄壁内，相邻缝隙相隔半个导波波长，且倾斜角相反，以实现交叉极化抵消。在每个缝隙上方放置一个开口端外部波导，用于极化纯化。缝隙波导的等效电路模型有助于设计。采用了一种使用切比雪夫分布的旁瓣抑制方法。提出了四种类型的阵列，所有这些阵列在汽车雷达的不同需求和应用中都显示出潜力。基于仿真设计制作并测量了原型。
