微波光子循环移频实现大带宽高精度射频频率测量

A Wideband and High Resolution Frequency Measurement Using a Cyclic Frequency Shifting Microwave Photonic Method

文中采用微波光子循环移频的方法实现了高精度、超宽带、多频率成分射频信号频率的测量,采用傅里叶变换的方法来提高频率测量精度。同时采取了精确控制脉冲时间的方法来抑制循环移频过程中的波形失真并提高测量系统的信噪比。实验结果表明,在0.25 GHz~50 GHz频率测量精度优于1 MHz,并可实现对多个频率成分的同时测量,且可以通过提高环路延迟时间与进行ADC校准来进一步提高频率测量精度。

In this paper,we demonstrated a method to realize high resolution,wideband and muti frequency raido signal frequency measurement based on microwave photonic cyclic frequency shifting method,and the Fast Fourier Transform method is used to improve the frequency measurement accuracy.Meanwhile,the pulse time is precisely controlled to suppress the waveform distortion in the cyclic frequency shift process and improve the signal-to-noise ratio of the measurement system.The experimental results show that the frequency measurement accuracy is better than 1 MHz in the range of 0.25 GHz~50 GHz,and multiple frequency components can be measured simultaneously.The measurement accuracy can be further improved by increasing the loop delay time and performing ADC calibration.