论文部分内容阅读
仪表着陆系统(ILS)作为目前国际上通用的飞机着陆系统,其标准信号源合成的复杂低频信号对调制信号的稳定度和准确度要求较高,频率合成技术成为目前研制ILS信号源的关键。介绍了一种采用直接数字频率合成技术的设计方案,较为详细地阐述了标准信号源的设计原理,调制信号合成模块和DDM控制模块的设计与实现,并给出了软件控制框图。系统合成的调制信号调制度差精度高,且系统结构简单、使用方便、性能稳定可靠。
As a commonly used aircraft landing system in the world, the instrument landing system (ILS) requires complex low-frequency signals from standard signal sources to modulate the stability and accuracy of modulated signals. Frequency synthesis technology is the key to develop ILS signal sources. A design scheme based on direct digital frequency synthesis is introduced. The design principle of the standard signal source, the modulation signal synthesis module and the DDM control module are described in detail. The software control block diagram is also given. Modulation signal modulation system with poor precision, and the system structure is simple, easy to use, stable and reliable performance.