Estimate of the Signal Delay in the Calibrator of the GNSS Signal Simulators

Radio frequency tract of the radio navigation equipment, as a rule, has a dependence of the passage time of the radio signal on the carrier frequency. Taking into account the number of navigation signals, which number will go on to grow in the future, it is necessary to develop measuring instruments that have a flexible architecture for newly introduced navigation signals and allow ensuring the uniformity of measurements of the radio navigation equipment with an accuracy no lower than it achieved by modern science and technology. The article discusses the calibrator of the navigation signal simulator and its features of metrological support. The developed calibrator must have several control points for checking its metrological characteristics with traceability to reference standards of pulse electrical voltage. The key node of the calibrator is group time delay of an analog-to-digital converter, which must be estimated during exploitation. A method for constructing the phase-frequency response of an analog-to-digital converter to determine its group time delay was tested, and the results are presented in the article.