基于多路移相时钟的瞬时测频模块设计

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4路同频率但不同相位的移相时钟,结合等精度测频的原理,在实际闸门开启时段分别对每路时钟的脉冲个数计数,通过计数值相加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4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.

Design of the instantaneous frequency measuring module based on phase shifted clocks

In the text,a novel instantaneous frequency measure module,which is applicable for the frequency measure system of frequency hopping radar,is presented based on the digital phase-shift clocks.The module generates 4-routes phase-shifted clocks with the same frequency but not the phase by the PLLs in FPGA,and records the generated clocks' pulse numbers dur- ing the measuring process by 4 counters according to the measure theory with uniform preci- sion.At the same time the adder in FPGA adds the all numbers.T...