脉冲多普勒气象雷达发射机相位稳定性分析

Phasic Stability Analysis of Pulse Doppler Weather Radar Transmitter

简要介绍了低相位噪声多普勒天气雷达发射机的特点和组成,脉冲多普勒气象雷达对发射机相位稳定性的要求,发射机满足脉冲多普勒气象雷达的要求所面临的关键技术问题。为了改善相位噪声,在发射机中采用了全固态调制器、回扫充电技术、充电校平技术和同步交流方波稳流灯丝电源等技术。分析了发射机影响脉冲多普勒气象雷达检测性能的主要因素以及射频脉冲信号受寄生调制的影响而产生的边带相位噪声,发现在发射机射频信号中不需要的寄生调制和噪声是由一系列源产生的,影响脉冲多普勒气象雷达相位稳定性的主要因素有射频激励源、电源纹波、脉冲时间抖动、幅度调制、颤噪效应、电磁感应和电磁干扰辐射源等。这些不需要的边带噪声限制了脉冲多普勒气象雷达在杂波中探测目标的能力。

A brief introduction is made to the characteristics, structure, and phase stability requirement of the low-phase noise Doppler weather radar transmitter, as well as the key technique problems in having transmitter meet the requirement of the pulse Doppler weather radar. To improve the phase noise, several technique used in the transmitter, including the full-solid modulator, flyback electrification, electrification verification, and synchronous AC square-wave steady-current power supply and so on. An analyzed are made of the main factors that influence the inspecting performance of the pulse Doppler weather radar and the side-band phase noise resulted from the effect of the autoeciousness modulator on the RF pulse signals. The analysis results indicate that the unneeded autoeciousness modulation and noise are produced by a series of sources, and the main factors influencing the phasic stability of the Doppler weather radar include RF-Driven sources, power-supply ripple waves, pulse time jitter, amplitude modulation, microphonic effect, electromagnet induction, electromagnetic interference radiation sources, etc. These unneeded side-band noises limit the sounding capability in clutter of theDopplerweather radar.