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声光偏转效应可用于信号载频相关信息的测量。但当多个射频信号同时加载到声光偏转器时,在布拉格条件下信号间将发生互调现象,给信号检测带来很大的困难,尤其是三阶互调光束的干扰尤为严重。针对这种声光衍射产生的互调干扰,从声光衍射互作用原理出发,讨论了产生互调现象的条件、衍射分布和信号频谱图。通过理论分析,提出了减小互调现象的方法和措施。构建测试系统平台,对多路信号同时到达声光偏转器时产生互调干扰的程度进行了实验验证。在声光偏转器有效带宽内,衍射效率一定的情况下,通过适当控制射频驱动功率,保证声光偏转器工作在线性区域,可有效地减小互调干扰,从而有利于系统的信号检测。
Acousto-optic deflection effect can be used for signal carrier frequency measurement of information. However, when multiple RF signals are simultaneously loaded into the acousto-optic deflector, intermodulation phenomenon occurs in the Bragg signal, which brings great difficulties for signal detection. Especially, the interference of the third-order intermodulation beam is particularly serious. In view of the intermodulation interference caused by this acousto-optic diffraction, the conditions of intermodulation, diffraction distribution and signal spectrum are discussed based on the principle of acousto-optic diffraction interaction. Through theoretical analysis, we put forward methods and measures to reduce the intermodulation phenomenon. The test system platform is constructed to verify the degree of intermodulation interference when the multi-channel signals reach the acousto-optic deflector at the same time. Under the effective bandwidth of the acousto-optic deflector and the diffraction efficiency, by properly controlling the RF driving power and ensuring the acousto-optic deflector working in the linear region, intermodulation interference can be effectively reduced, which is in favor of system signal detection.