基于软件无线电的VOR射频激励源研究

VOR RF actuator research based on software defined radio

在对机载VOR接收机进行测试与维护时,需要提供可以模拟地面台射频信号的激励源;目前使用的射频激励源一般为传统的专用硬件设备,存在调制参数固定、无法灵活调节等问题。为解决该问题,对VOR射频信号原理进行了分析,基于软件无线电原理,对VOR射频激励源进行了设计;采用零中频软件无线电结构,在计算机上实现对VOR射频信号的正交调制,从而能够对调制参数进行灵活调节,并通过通用的硬件平台发射VOR射频信号;系统可通过人机交互界面、网络或GPIB方式进行控制。使用频谱仪对系统进行了测试,并将输出的射频信号进行记录后,导入到Matlab进行分析验证。结果表明,系统误差在允许的范围内,能够为VOR接收机提供符合要求的射频信号。

To test and maintain the VOR receiver, an actuator which can simulate the ground station RF signal is needed. The current use of RF actuator is generally traditional special hardware equipment, the parameters could not be adjusted flexibly, and the price is higher. In order to solve this problem, the principles of VOR RF signal are analyzed; VOR RF actuator based on SDR is designed. The zero-IF software radio structure is used. The RF sig- nal transmitted through the universal hardware platform is quadrature modulated on computer, and the modula- tion parameters can be adjusted flexibly. The system could be controlled through human-machine interface, network or GPIB. The system is tested by spectrum analyzer and RF signal of the system is recorded and ana- lyzed through Matlab. Results show that the system error is acceptable according to relevant standards, and could provide the VOR receiver with adjustable RF signal.