Bridging RF-voltage to coaxial power standard in the 100 MHz range

Electromagnetic power standard realized by means of the microcalorimetric technique fails below some MHz because of a reduced sensitivity of the system. This causes a metrological lack in the calibration of coaxial power sensors whose broadband characteristics span from dc up to 50 GHz. However, as coaxial transmission lines admit pseudo potential functions, power meter calibration can be done in term of radio frequency (RF) voltage from dc up to 100 MHz at least. The paper describes how INRIM works around the drawback of the microcalorimeter at low frequencies.