Design of Microwave Medium Power Meter with Thermal Equilibrium Judgement Algorithm

A new design of power meter for microwave medium and high-power measurement is introduced. In medium power calorimetric measurement, temperature fluctuation is relatively severe comparing to small power. Algorithm of thermal equilibrium judgement is specially included, to minimize slow thermal variation and reduce measurement time cost, especially in large power level. This power meter is capable of measuring microwave power in 10W-100W power range and DC-8GHz frequency range. Besides, thermal compensation is applied with monitoring thermal sensor PT1000. Measurement results are compared with conventional fixed-duration method, where standard deviation remains less than 1%. Measurement time cost for each power level is shortened from 30 minutes fixed duration to 12.37 minutes in average. Both measurement efficiency and accuracy are remarkably improved by using designed power meter.