Hall Effect and its Counterpart, Radiation Pressure, in Microwave Power Measurement

Hall effect and radiation pressure are shown to be different manifestations of the same basic phenomenon, and their relationship is deduced for a plane wave transmitted through a slab of material of given electrical characteristics. In particular, the contributions to these effects of both the conduction and displacement components of current in the material are examined, and it is shown that the latter can be a significant supplementary factor at ultra-high frequencies. Both Hall effect and radiation pressure have been used for microwave power measurement, and some aspects of these applications are discussed in the light of the present analysis. To permit a better assessment of the Hall-effect-wattmeter problem, numerical calculations have been made at 4000 Mc/s for n-type germanium and silicon showing that a high-resistivity material is necessary to achieve a satisfactory performance with a transmission type of instrument. Similar computations for polythene predict that a measurable Hall effect arising from displacement current in this material should exist, and it is suggested that observations based on that effect might offer a new approach in further exploration of the properties of dielectrics.