Microwave frequency power measurement is one of the main types of the measurement for measuring instruments and systems in the radio frequency range. Therefore, improving the accuracy of measuring the microwave frequency power requires the establishment of more precise standards, and the development of calibration methods for meters of microwave frequency power is an urgent task. Microwave frequency power standards that are used to calibrate the relevant measuring instruments must ensure high accuracy of the unit size reproduction over a wide measurement and frequency range. The study allowed determining typical calibration schemes for meters of microwave frequency power. For measurements, the calibration scheme for meters of microwave frequency power by the method of a direct comparison with the help of a calibrator when measuring the absorbed power of microwave frequencies is substantiated and suggested. The proposed methodology for evaluating the uncertainty of absorbed power measurements can be used when calibrating power meters in the frequency range from 30 MHz to 18 GHz. It allows determining the most significant components of the combined standard uncertainty of the absorbed power measurements of ultrahigh frequencies, as well as to receive the result of the corresponding calibration. This methodology can also be used to evaluate the uncertainty of microwave frequency directional measurements.

High-frequency (HF) and ultra-high-frequency (UHF) power measurements are applied in various industries both in the development and design of radio-electronic equipment and in testing, commissioning, or repair. Since such measurements are one of the basic types of measurement for metrological support in the field of radio engineering and communication, it is necessary to ensure metrological traceability of the calibration of working standards and measuring instruments to standards on fundamental constants in wide frequency and dynamic ranges. The National primary standard of Ukraine for units of power of electromagnetic oscillations in coaxial paths reproduces units of power in the frequency range 0.03 … 18 GHz, and the frequency range of the nomenclature of watt-meters and power converters are much wider – from 9 kHz, and for some types of converters even from direct current. The calibration and measurement capabilities of HF and UHF power measurement of national laboratories of different countries were studied for the possibility of solving the issue of expanding the frequency range of calibration of HF and UHF power meters. The analysis of data on the calibration factor and the efficiency factor in coaxial paths with a resistance of 50 Ohm in the Database of Key Comparisons of the International Bureau of Weights and Measures was carried out. A study of possible solutions was carried out and a scheme was developed to reproduce a unit of power by units of voltage and resistance using a precision voltmeter Boonton 9242 RF for the calibration of measuring transducers Rohde&Schwarz NRP-Z55 and NRP6A in the frequency range from 0.1 … 30 MHz. A reproduction model was created based on the developed scheme, and the contributions of the reproduction model components to the calibration result and the corresponding uncertainties of the model components were estimated. The measurement uncertainty budget was drawn up based on the proposed calibration model of radio signal power measuring transducers.