A new measurement method for group delay of frequency-translating devices based on software defined radio technology

摘要

A precise measurement for the group delay of Frequency-Translating Devices (FTD) is always a difficult problem in measurement field. It almost has no choice but the modulation method for measuring group delay especially the group delay of FTD which can't accept the other local oscillator. To resolve the problem that a precise measurement method for group delay of FTD, a new double-frequency phase difference method has been put forward based on software defined radio technology (SDR). This method is especially suitable for measuring group delay of FTD which can't accept the other local oscillator. The formula of the new method is deduced in detail in this paper. This paper concentrates on two aspects of the practice system: the design and the measurement method. The simulation shows the accuracy of this method is better than the traditional modulation method by 1 order magnitude.