Characteristics of Transverse Electric and Magnetic Field Transmission Cells at Extremely Low Frequencies

摘要

Transverse electric and magnetic field cells are often designed to subject samples to electromagnetic radiation of intrinsic impedance (E/H) that is the same as in free space, 377 ohms. Earlier work has shown this value to be correct for the RF region. In the study, measurements of magnetic field in the extremely low frequency regions and at dc indicate the E/H ratio to be around 300 ohms for frequencies less than 2 kHz in cells of a particular design. The lower value may, in part, be due to a redistribution of current in the central conductor as the frequency is lowered. (Copyright (c) Alan R. Liss, Inc., 1987.)