摘要
本文根据时钟数字移相原理,提出了一种新的瞬时测频方法,适用于捷变频雷达测频系统。该方案利用FPGA芯片内部的PLL产生了16路同频率但不同相位的移相时钟,结合等精度测频的原理,在实际闸门开启和关闭的时刻分别记录这16路时钟的电平信号得到时钟相位代码,通过代码转换和计算获得标准时钟计数值,等效为将单路标准时钟的频率提高16倍。实验板验证结果表明,该方案电路简单、成本低、性能稳定,能满足技术指标要求。
In the paper, a novel instantaneous frequency measure method, which is applicable for the frequency measure system of frequency hopping radar,is presented according to the digital phase-shift theory. By the PLLs in FPGA, the module generates 16-routes phase-shifted clocks with the same frequency but not the phase According to the measure theory with uniform precision, the generated clocks＇ levels used to bring the codes of clocks＇ phases are recorded at the moments of the counting process beginning and over, and then obtain the standard clock＇s counts by transforming and calculating the phases＇ codes. The method raises 16 times the frequency of counter＇s clock equally and results a simple electric circuit, a low cost and a stable function while satisfying the technique index required.
出处
《电子测量技术》
2007年第7期155-157,共3页
Electronic Measurement Technology
关键词
瞬时测频
数字移相时钟
锁存码值
等精度
instantaneous frequency measure
digital phase shift
clock phase-code
uniform precision
