Design of a high-precision temperature-voltage converting circuit applied to RF power calorimeter

In this paper, a study of a high-precision temperature-voltage converting circuit for RF power calorimeter is presented. It consists of a constant current source and a matching output part. Both of two parts are designed and implemented in order to calibrate RF power. The development of RF power calibration is based on the principle of substituting direct power for RF power, which is very mature technique in theory. The performance of converting circuit with high precision and good stability is tested under DC calibration power, the relative error of test results and analysis results is just 4.25%, and the result meets the demand of the calorimetric small power standard.