In transmitting antennas a second cause of power wastage is dielectric power losses of the electric field (displacement current) of the antenna passing through the earth to reach the ground wires. For antennas near a half-wavelength high (180 electrical degrees) the antenna has a voltage maximum (antinode) near its base, which results in strong electric fields in the earth above the ground wires near the mast where the displacement current enters the ground. To reduce this loss these antennas often use a conductive copper ground screen under the antenna connected to the buried ground wires, either laying on the ground or elevated a few feet, to shield the ground from the electric field.