counterpoise

counterpoise, in electronics, portion of an antenna system that is composed of wires or other types of conductor arranged in a circular pattern at the base of the antenna at a certain distance above ground. Insulated from the ground, it forms the lower system of antenna conductors. It is used in places where it is difficult to obtain a good ground (e.g., where there is extremely rocky soil). A combination of counterpoise and buried-wire grounds is also possible.