The Use of Screened (Shielded) Rooms for the Identification of Radiation Mechanisms and the Measurement of Free-Space Emissions from Electrically Small Sources

The electric field measured in a screened (shielded) room using a 41-in rod antenna is dependent upon the geometry and size of the test setup, the type of source (electric or magnetic dipole), and the dipole moment. In this paper, experimental results and a computer model based on TEM wave propagation within the room are used to evaluate the differences between the dipole fields measured in a screened room, and the fields that dipoles of the same moment radiate in free space. A technique for identifying the type of source is suggested.