International comparison GT-RF 75 A 11: RF power at 12 GHz, 14 GHz and 17 GHz in 50 Ω coaxial line

This paper deals with the results of an international comparison measurement of the effective efficiency E of commercial 50 Ω/7 mm coaxial thermistor RF power standards fitted with PC-7 precision connectors. The measurement frequencies were 12 GHz, 14 GHz and 17 GHz. The national laboratories of metrology of eight countries (Australia, Canada, France, Hungary, Italy, the Netherlands, USA and Germany) participated in this comparison which was organized by the Radio Frequency Working Group of the Comite Consultatif d´Electricite (CCE). The Physikalisch-Technische Bundesanstalt (PTB, Germany) acted as the pilot laboratory. The standards showed only a small linear negative drift in E, as found by linear regression analysis. For most of the mean values of E reported by the laboratories, the deviations from the regression values were small (not larger than 0.004); only in two cases were the deviations 0.006 and 0.0085