基于相位校正信号的变频系统时延测量方法

针对现有群时延测量方法在宽带变频系统测量中,测量效率低、没有有效的群时延解模糊方法的问题,提出了一种基于相位校正（phase calibration,PCAL）信号的高精度时延测量方法和基于扩展中国余数定理（Chinese remainder theorem,CRT）的时延解模糊方法。利用PCAL信号梳状谱的频率特性,通过一次测量即可得到整个测试带宽内不同孔径下的群时延特性。推导了扩展CRT算法稳健的条件,给出了详细的群时延解模糊策略。计算机仿真结果表明,新方法的相对时延测量精度和相对解模糊精度最高可达到ps量级。实际设备测试结果表明,相对时延测量精度达到了0.01 ns量级,CRT相对解模糊精度约为0.1 ns量级。

Delay measurement method for frequency converting system using phase calibration signal

There are two problems in the measurement of the wideband frequency converting system using existing methods. One is inefficiency in measurement, the other is without effective group delay ambiguity resolution method. A new delay measurement method based on phase calibration (PCAL) signal is proposed and a group delay ambiguity resolution method based on extended Chinese remainder theorem (CRT) is given for solving the problems. The whole group delay characteristic of the tested bandwidth can be obtained by only one measurement according to the frequency characteristic of the PCAL signal. The robust condition of the extended CRT is derived. The ambiguity resolution strategy is detailed. Computer simulation results show that the delay measurement relative accuracy and the ambiguity resolution relative accuracy can reach the order of ps. The field experiment results show that the delay measurement relative accuracy reaches the order of 0.01 ns and the ambiguity resolution relative accuracy reaches the order of 0.1 ns.