多周期同步鉴频法闸门效应及其频谱补偿技术

The Gate Effect of the Multi-period Synchronous Frequency Discrimination Method and its Compensation Method

假设被测信号为时域内固定频率的正弦波并以其为研究对象,构建了多周期同步鉴频以闸门时间为自变量的传递函数,并运用该函数进行闸门效应对鉴频精度影响规律的推导,分析了多周期同步鉴频法的幅频和相频特性,提出一种多周期同步鉴频法中基于被测信号频谱进行实时补偿的技术。实验表明:频谱补偿法可有效减小由于闸门效应而引入的误差,从而有效提高仪器的测量精度。

This paper takes a certain frequency resonant wave, such as the measured signal, as the research object in the time domain, constructs a universal transfer function of the multi-period synchronous frequency discrimination in a certain gate time and analyzes the principle and effect on the accuracy of gate effect based on this function; introduces the amplitude-frequency and phase-frequency characteristics of the multi-period synchronous frequency discrimination system according to the analysis of the gate effect; also presents a real-time compensation method based on the different frequency components. The experimental data show that the real-time compensation method can eliminate effectively the demodulation error caused by the gate effect.