电离层探测仪多通道激励源的设计

新设计的系统采用5通道激励源,使用5副对数周期天线作为发射阵列,采用数字波束技合成技术控制天线阵列。除原有的调相脉冲体制,增加了线性调频连续波体制,此体制具有良好的距离分辨率和多普勒不敏感性,可实现对快速运动目标的跟踪探测。每个激励源采用可编程门阵列为主时序控制器,直接数字频率合成进行频率合成,PC机与发射机之间的通信利用通用串行总线架构来实现。采用模块化设计,便于后续的维护和升级。目前已应用于实验室的日常探测之中。

Design of Ionosonde Multi-channel Excitation Source

New-designed system(WMI) uses 5 channels excitation source, so it uses 5 pairs log periodic antenna as the transmitting array. WMI adopted frequency modulated continuous wave as an additional waveform based on previous waveform. The new waveform have high range resolution and low Doppler sensitivity, so WMI can detect and track fast moving target. Each excitation source is consisted of FPGA to control central time, DDS and USB which is responsible for the communication between computer and the system. The system is designed according to the idea of modularization, so it is very easy to update and maintain. Now this system is already used in daily detection in laboratory.