一种新的噪声系数测量方法  

A New Method of Noise Figure Measurement

作　　者：王瑛[1] 朱祥维[1] 王飞雪[1] 

机构地区：[1]国防科技大学电子科学与工程学院卫星导航定位研发中心,湖南长沙410073

出　　处：《电子学报》2005年第6期1132-1135,共4页Acta Electronica Sinica

基　　金：国防预研项目(No.106010304);湖南省杰出青年科学基金(No.04JJY1011)

摘　　要：测量含有自动增益控制(AGC)电路的射频模块噪声系数时,使用Y因子法将改变模块的功率增益,进而无法测定.本文提出了一种新的噪声系数测量方法.该方法在信噪比较小的条件下用误码率推算前端的载噪比,避免了用仪器标定载噪比受信道滤波器通带平坦性影响较大的问题;测量过程中,AGC输入端信号和噪声的总功率几乎不变,能够保证AGC功率增益不变,从而可准确测量含有AGC电路的射频模块噪声系数.通过理论推导和数值模拟分析了随机误差、系统误差、实验温度以及测量次数对噪声系数估计的影响,验证了方法的有效性.本文成果已用于我国“北斗一号”卫星导航定位用户机的射频模块测量.Y-factor method cannot measure the noise figure of RF module with Automatic Gai n Control (AGC) because it will change the power gain of the module.A new method of noise figure measurement is presented.The method has two important features: estimation of Carrier-to-Noise Ratio (CNR) in front-end with the knowledge of error rate,thus the effect due to the inconstant amplitude versus frequency c haracteristic over the measurement bandwidth can be avoided;almost constant tota l power of signal and noise at input of AGC and constant gain of AGC during the measurement,hence the noise figure of RF module with AGC circuit can be measure d accurately.The effects of random error,system error,ambient temperature and m ea surement times on the estimation of noise figure are analyzed by theoretical der ivation and numerical simulation,and the results prove the validity of the meth o d.The research result has been applied to the satellite navigation and positioni ng System.

关 键 词：噪声系数 自动增益控制 载噪比 误码率 

分 类 号：TN911.4[电子电信—通信与信息系统]