基于虚拟仪器技术，设计了一种用于谱分析的多频涡流检测系统，重点对其激励信号的设计和优化问题进行了研究。激励信号通过软件方式进行合成，包括同步加法合成激励和调制频率合成激励。在同步加法合成激励方式中，对各频率分量的初始相位进行优化，降低峰值因数。在调制频率合成激励方式中，选择Tukey窗函数，可有效抑制检测信号频谱中的纹波。

A multi-frequency eddy current testing system based on spectrum analysis method is designed with virtual instrument technique. Design and optimization of testing systems excitation signals are studied. The excitation signal is generated with software in simultaneously synthesized method or in frequency modulation method. The initial phases of each frequency component are optimized to reduce crest factor in the former method. Tukey window function is adopted to eliminate ripples of testing signals spectrum in the latter method.