Using Radiation Pressure to Develop a Radio-Frequency Power Measurement Technique Traceable to the Redefined SI
Christopher L. Holloway, Matthew T. Simons, David R. Novotny, John H. Lehman, Paul A. Williams, Gordon A. Shaw
We discuss a power measurement technique traceable to the International System of Units based on radiation pressure (or radiation force) carried by an electromagnetic wave. A measurement of radiation pressure offers the possibility for a power measurement traceable to the kilogram and to Planck's constant through the redefined SI. Towards this goal, we performed measurements of the radiation pressure from a radio-frequency (RF) electromagnetic field at three frequencies (26.5~GHz, 32.5~GHz, and 40.0~GHz) and power levels (ranging from 2~W to 25~W) using a commercially available mass scale. We show comparisons between the RF power obtained with this technique and those obtained with a conventional power meter. The results in this paper are the first step towards the realization of a more direct link to RF power within the newly redefined SI.