Transfer System Of Broadband National Power Standard

High frequency and microwave power is a basic parameter in radio measurement, the nicety unification values of which are of importance technology foundational guarantee to our national defense and the development of technology. It is obliged to improve the power transfer system ceaselessly.The type N coaxial power transfer system is commonly used for high frequency and microwave power transfer. The transfer system is designed by making use of existing laboratory resources. With the analysis of transfer standard theories, the research work is focused on the measurement of equivalent source reflection coefficient, which is the main uncertainty source of microwave power meter calibration factor. The Monte Carlo method is adopted to evaluating uncertainties of equivalent source reflection coefficient and calibration factor. The operating principle of commercial power meter is studied to design the improved calibration system for diode power sensor. With the measurement results, the performance of the improved system is analyzed and verification.The main research contributions of this dissertation are as follows:1) The mathematical models of equivalent source mismatch and power meter calibration include many complex stochastic issues and functions. To solve the problems, the Monte Carlo method is applied to evaluate uncertainties of equivalent source reflection coefficient and calibration factor. Different from the traditional Law of Uncertainty Propagation, the Monte Carlo method can obtain coverage factors of measurement uncertainties accurately and not increase the uncertainties.2) The improved calibration system can obtain correction factor of the diode power sensor accurately from 10MHz to 18GHz and incident power form -70dBm to 20dBm. The experimental results indicate that it is better than current calibration set used in manufactory, then it will be of benefit to the users of diode power meter.