基于非线性扫频的频率特性校准研究

摘要

The traditional method uses linear frequency modulated signal as the excitation for frequency response measurement and calibra-tion, which can hardly balance the accuracy and efficiency because of its even power spectrum and deficient adjustable parameters. In this paper, we propose a dynamic method for frequency response calibration based on nonlinear frequency sweep. The power spectrum of the nonlinear sweep signal is inhomogeneous, so that the accuracy and efficiency of the calibrating method can be well balanced. The simulation result shows that compared with the traditional method using linear frequency sweep, our method improves the measurement accuracy within specific frequency band using the same sweeping time.%在动态频率特性测量和校准应用中，传统的线性调频信号频谱均匀分布、可设计参数单一，难以同时兼顾测量精度与测量效率。本文提出了一种基于非线性扫频方式的动态频率特性校准方法，可广泛用于传感器与仪器仪表的频率响应校准与标定。非线性扫频信号可以实现激励信号能量在频域内的非均匀分布，从而在某些重要频段内实现较高精度测量的同时，在其他频段通过牺牲一定的测量精度来保证测量速度，从而进一步优化频率特性测量的整体性能。仿真结果表明，在相同的扫频时间内，非线性扫频方法相比于线性扫频方法，能够将特定频段内的测量精度进一步提高。