The quad antenna consists of two or more square loops of wire. The driven element has an approximate overall length of:

A quad antenna is a type of directional beam antenna built using square loops of wire. Unlike a traditional Yagi antenna which relies on half-wavelength straight elements, the driven element of a quad antenna is a continuous, closed loop. The overall perimeter of this driven loop measures approximately one full wavelength. Because it forms a square, each of the four sides measures roughly one quarter of a wavelength.