Loop antenna
A small loop antenna, also known as a magnetic loop, generally has a circumference of less than one tenth of a wavelength, in which case there will be a relatively constant current distribution along the conductor.  As the frequency or the size is increased, a standing wave starts to develop in the current, and the antenna starts to acquire some of the characteristics of a resonant loop (but is not resonant); for this reason, these intermediate cases cannot be analyzed using the concepts developed for the small and resonant loop antennas described below.