Vector network analyzer usage at calibration of delay in satellite radio navigation system signal simulators

This article presents a method of vector network analyzer application at the task of global navigation system simulator calibration. Calibrated parameter is internal delay of the radiofrequency signal in simulator. Attention is payed to reducing of calibration uncertainty by means of taking into account the part, which is caused by impedance of simulator and other equipment mismatches. The goal of research is to estimate the non-excluded uncertainty after vector network analyzer measurements’ usage for correction calculation. Measured parameters are the group delay, reflection and transmission coefficients of cable with connectors, and reflection coefficients of simulator and oscilloscope. The goal has been achieved by means of simulation modelling. The main parts of modelling were simulation of vector network analyzer measurements’ and calculation the statistics of the non-excluded uncertainty. As the result, was shown, that if to use vector network analyzer for global navigation system simulator calibration, the part of uncertainty, caused by impedance mismatch, can be reduced in a several times.