driven element (antenna)
Technical term in antenna engineering; the part of an antenna that is directly connected to the transmission line and radiates the signal.
In a Yagi antenna, the length of the driven element determines the resonant frequency.
A director element in a Yagi antenna, which is shorter than the driven element and helps focus the signal forward.
A reflector element in a Yagi antenna, which is longer than the driven element and reflects the signal back toward it.
Compound of 励振 (excitation, driving) and 素子 (element, device). The term is a direct technical description of the component's function in an antenna system.