摘要
对变频系统群时延的精确测量,一直是测量领域的难题,尤其是外本振无法接入的变频系统,测量精度较低的调制法几乎成了测量其群时延的唯一选择。本文从群时延定义出发,提出了一种全新的群时延测量方法——基于软件无线电技术的双频相差法,该方法特别适用于外本振无法接入的变频系统群时延的精确测量。本文详细说明了双频相差法的基本原理,给出了实验测试系统的设计和测试方法。仿真测试结果表明双频相差法的测量精度比传统的调制法提高约一个数量级。
Precise measurement for group delay of Frequency-Translating Devices （FTD） is always a difficult problem in measurement field. Modulation method almost becomes the exclusive choice to measure the group delay especially for the group delay of FTD that can＇t accept other local oscillator. To resolve the problem of precise measurement of the group delay of FTD, a new double-frequency phase difference method come from the definition of group delay has been put forward based on software defined radio technology （SDR）. This method is especially suitable for the precise measurement of FTD that can＇t accept other local oscillator. The formula of the new method is deduced in detail in this paper. This paper concentrates on the design and the measurement methods of an experimental system. Simulation result shows that the accuracy of this method is better than that of traditional modulation method by 1 order magnitude.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2010年第1期166-171,共6页
Chinese Journal of Scientific Instrument
基金
航天支撑技术基金项目(2008-HT-HGD-16)资助
关键词
群时延
变频系统
软件无线电
双频相差法
group delay
FTD
SDR
double-frequency phase difference method
