A mode-expansion theory for the EM fields from a circular loop antenna

Authors

  • Hsi-Tien Chang


Abstract

The electric and magnetic fields from a circular loop antenna are decomposed into various field modes which depend only on the coordinate system being used. These modes can be calculated in advance even if the source and loading function of the antenna are unknown. The excitation factor for each mode, which is related to the current distribution on the antenna, is the only variable that must be determined from time to time as the loading impedance and the source function of the antenna are changed. It is found that the mode-expansion technique is quite convenient for field computation at many locations where only a few modes will be sufficient to represent the field distribution.

Ancillary