Research And Development Of Metrological Microwave Power Meter

High frequency and microwave power is the most basic parameter in electronic metrology, and it is of great importance to perform accurate measurement of high frequency and microwave power. As a fundamental metrological device, the millimeter-wave power meter plays a significant role in the metrology system of millimeter-wave. In order to enhance the metrological level, it is crucial to develop a set of millimeter-wave power meter that can serve the metrology system.In this thesis, we focus on the development of metrological millimeter-wave power meter, which can perform accurate measurement in WR-22(33-50GHz) band. The practical application can be benchmarking standard power sensors with the help of power benchmark, as well as delivering standard and calibrating the subordinate power sensors. Hence, this domestic power meter is able to serve in the national millimeter-wave benchmark and the calibration system of power measurement devices.Measurement techniques based on DC substitution are thoroughly studied and properly employed, and a series of subtle technologies are adapted in the process of development. All in all, this thesis presents the main achievements as following:1. The four-wire self-balanced bridge that owns the highest accuracy is selected, and the precision covering all concerned frequency bands is confirmed as (0.01%±1μW).2. Targeting at the low stability with very low input power, a differential voltage measuring method is proposed. After long-term test, verification, and error analysis, the fact has proved that the precision when power input is lower than5mW has increased10%.3. Faced with the strict requirement of measuring circuit for constant temperature, an external temperature controlling system is developed to ensure the temperature stability of the controlled objective. The temperature variation is limited in a range of not more than0.01℃/10min.4. The power meter is applied in the calibration system of power sensors. Moreover, the power standard delivery is set up to calibrate the power sensors. Last but not the least, the uncertainty of the whole calibration system is evaluated.After all these work accomplished, this power meter is applied in the calibration in NIM, which simplifies the calibration process and proves to be reliable.