车号识别系统的收发天线研究

Research on transmitting/receiving antenna of vehicle number identification system

收发天线采用微带矩形贴片天线阵 ,本文用传输线模型法分析和设计。为简化分析 ,辐射单元被看成是由一段低阻抗传输线连接的两个缝隙。本文给出了开路半波谐振器及微带线阵的设计方法与步骤。该天线在设计时选用最小单元间距方法 ,减小天线体积 ,同时易于匹配 ,提高增益带宽。在 90 2 MHz～ 92 8MHz工作时 ,实测天线驻波小于 1.4 ,增益大于 9d B,半功率波瓣宽度大于 6

Microstrip rectangular patch antenna array is used as transmitting/receiving antenna.Transmission line model theory is applied in the analysis and design in this paper.In order to simplify the problem, the radiating element is considered as two slots separated by a transmission line of low characteristic impedance.A design procedure for open circuit half wave resonators and for array of such resonators is given.Minimal distance between units is chosen to minimize the volume of antenne, easy to be matched increase gain and widen bandwidth .An array antenna in which VSWR less than 1.4,gain more than 9 dB and half beam width reached 60 degree is attained.