基于SIR结构的毫米波汽车雷达天线阵列设计

为了提高汽车雷达天线阵列的增益，使形成窄波束辐射，设计了一款工作在24.000 GHz的阶梯阻抗谐振器(stepped impedance resonator，SIR)微带阵列天线。天线阵列采用两级低损耗T型结功率分配器和四分之一波长微带阻抗变换器馈电，将四个SIR线阵单元组成天线阵列。通过增加SIR微带贴片的数目来提高阵列天线的增益，调整SIR的尺寸以控制工作频带，利用功率分配器进行阻抗变换和波束宽度控制。天线阵列的峰值增益可达到21.67 dBi。在中心频率24.125 GHz上，XOZ面的主瓣宽度为10°，YOZ面的主瓣宽度为17°，旁瓣抑制度为11 dB。该阵列天线面积小、增益高、波束窄、旁瓣电平低、后向辐射小，适用于汽车雷达系统。

Design of Millimeter Wave Automotive Radar Antenna Array with SIR Structure

In order to improve the gain of the automotive radar antenna array and form a narrow beam radiation,a kind of 24.000 GHz stepped impedance resonator（SIR) microstrip array antenna is designed.Using a two-stage low-loss T-junction power divider and a quarter-wavelength microstrip impedance converter,the antenna array is formed with four SIR linear array elements.It increases the gain of the antenna array by increasing the number of SIR microstrip patches.The size of the SIR microstrip is adjusted to control the operating frequency band.The power divider is used to transform impedance and control beam width.Results show that the peak gain of the antenna array is 21.67 dBi.When the center frequency is 24.125 GHz，the main beam width of XOZ plane is 10°，the main beam width of YOZ plane is 17°，and the sidelobe suppression ratio is 11 dB.With small size,high gain,narrow beam,low sidelobe level and small backward radiation,the antenna array is suitable for automotive radar systems.