一种优化周期测频法数字频率计的设计  

Design of a digital frequency meter based on optimized cyclical frequency measurement method

作　　者：苟铭泽 崔少辉 魏保华 GOU Mingze;CUI Shaohui;WEI Baohua(Department of Missile Engineering,Army Engineering University,Shijiazhuang 050003,China;State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System,Luoyang 471003,China;63850 Army of PLA,Baicheng 137001,China)

机构地区：[1]陆军工程大学导弹工程系,河北石家庄050003 [2]电子信息系统复杂环境效应国家重点实验室,河南洛阳471003 [3]中国人民解放军63850部队,吉林白城137001

出　　处：《现代电子技术》2018年第23期175-178,共4页Modern Electronics Technique

基　　金：CEMEE国家重点实验室开放基金(2017Z0301B1).

摘　　要：针对在频率测试中使用周期测频法测高频信号存在较大误差的问题,设计了一种以现场可编程逻辑门阵列为核心控制器件的数字频率计。该频率计在采用周期测频法的基础上,同时设计了被测信号的量程估计模块和分频模块提高测试精度。该频率计不需人为设置量程,量程估计模块可以自动确定被测信号fx的频率范围。被测信号经过量程估计后,根据量程值确定分频数N,对fx进行10N分频,将分频后的信号作为闸门来进行精确的测量。由于被测信号经过分频,所得的闸门得到了相应的扩大,从而减小了测试误差。仿真结果表明,该频率计能够实现对输入频率范围在1 Hz～10 MHz的周期信号周期测量,测量精度在10-6。Since the cyclical frequency measurement method used to measure the high-frequency signal has large error in frequency test,a digital frequency meter taking FPGA as its core control device is designed.On the basis of cyclical frequency measurement method,the range estimation module and frequency division module of the measured signal are designed to im-prove the test accuracy.The range of frequency meter needn′t be set artificially.The range estimation module can automatically determine the frequency range of fx(signal under measurement).After the range estimation of the measured signal,the frequency division number N is determined according to the range value,and the fx is divided by 10^N.The signal after frequency division is used as a new gate for more precise measurement.The gate is broadened due to the frequency division of the signal,so the measurement error is reduced.The simulation results show that the frequency meter can measure the periodic signal whose input frequency is within 1 Hz^10 MHz,and the measurement accuracy is 10^-6.

关 键 词：周期测频 频率计 现场可编程逻辑门阵列 量程估计 分频 闸门 

分 类 号：TN911-34[电子电信—通信与信息系统] TH70[电子电信—信息与通信工程]