Parasitic element

from Wikipedia, the free encyclopedia
Yagi-Uda antenna with reflector R, active element A and a director D on the support rod T.

A parasitic element is an effective element of an antenna that is not connected to the transmitter or receiver by antenna cables like an active element.

In the case of a Yagi-Uda antenna , in addition to the active element ( dipole ), a reflector and one or more directors are typically attached as parasitic elements on the antenna support . These are only coupled to the active element via the electromagnetic waves and reinforce the directional characteristic of the dipole in the direction of the directors.

Directors are mechanically shorter and reflectors longer than the fed dipole.

literature

  • The ARRL handbook for radio communications 2011 . American Radio Relay League, Newington 2011.