Calibrating Dual-directional Couplers and Evaluating Uncertainties in Net Power Delivery

摘要

Dual-directional couplers are used to monitor net power fed into transmitting antennas in standard-field systems at NIM, China. It is essential to calibrate the coupler and evaluate the measurement uncertainty in the net power in such applications. The method we use at NIM to calibrate couplers are presented in this paper, and a complete model that takes into account the measurement uncertainties of couplers and horns to evaluate uncertainties in net power delivery is proposed. A case study is also provided of power delivery by a coupler with the nominal directivity of 40 dB using the Monte Carlo analysis based on the complete model and actual measured data.