A cage antenna (British cage aerial) is a radio antenna where a conventional design has been augmented by replacing a single long conductor with several parallel wires, connected at their ends, and held in position by ring spacers or support struts mounted on a central mast (if any). The "cage" is either mounted around a central mast (either conducting or non-conducting) or suspended from overhead wires.
A few examples of areal made of cage sections are:
In 1921, an amateur radio operator tried to win a $500.00 prize with his cage aerial. [3]