RF-DC differences of coaxial thermal standards

The RF-DC differences ( delta ) of thermal converters are calculated from complex transmission line theory. The Boella effect and the skin effect are considered. The formula delta =Af/sup 1/2/+Bf/sup 2/ can be obtained by experiments and proved by comparison of converters. The uncertainty of delta is 0.01% at 1 MHz and 0.1% at 30 MHz. >