一种监测雷达发射直达波天线设计

Design of an Antenna for Measuring the Direct Path Wave Transmitted by Radar

针对目前国内外广泛采用数字示波器与小功率计相结合的机外间接测量方式进行雷达功率标定,设计了一种小型微带天线,用监测直达波的方法来精确测量C波段多普勒双偏振天气雷达脉冲峰值功率,以此标定发射功率。根据微带天线的辐射机理,依据经典矩形微带天线公式,利用HFSS15.0软件建立天线模型,不断调整天线单元尺寸参数和馈电网络,优化改进物理参数,并对天线辐射特性进行仿真分析,设计出一个中心频率为5.59 GHz的微带天线。仿真结果表明,该天线谐振频率5.59 GHz的回波损耗为-15 dB,阻抗匹配良好;回波损耗小于-10 dB的带宽达到40 MHz,天线增益最大值为19 dB,3 dB波束宽度为19°。分析结果表明:该天线设计符合C波段天气雷达脉冲峰值功率标定需要,为我国C波段天气雷达发射功率的标定方式提供新的方法和思路。

Considering the indirect measurement method of combining digital oscilloscopes with small power meters is widely used in radar power calibration outside radars, the paper designs a kind of compact antenna receiving direct path wave to demarcate the pulse peak power of C-band double polarization Doppler Weather Radar, to calibrate the transmitting power. A microstrip antenna is designed at resonant frequency about 5.59 GHz by the simulation software HFSS. The simulation results show that the value of S11 at resonant frequency about 5.59 GHz is-15 dB which indicates that the microstrip antenna designs have good impedance characteristics, and its bandwidth is 40 MHz for return loss less than-10 dB. Meanwhile the maximum gain is 19 dB, and the 3 dB beamwidth is 19°. The analysis results show that the antenna design meets the requirement of peak power calibration of C-band weather radar. It provides a new method and idea for the calibration of transmitting power of most C-band weather radars in China.