Curtain arrays are a class of large multielement
directional wire radio transmitting
antennas, used in the
shortwave radio bands. They are a type of
reflective array antenna, consisting of multiple wire
dipole antennas, suspended in a plane, often in front of a "curtain" reflector made of a flat vertical screen of many long parallel wires. These are suspended by support wires strung between pairs of tall steel towers, up to high. They are used for long-distance
skywave (or
skip) transmission; they transmit a beam of radio waves at a shallow angle into the sky, which is reflected by the
ionosphere back to Earth beyond the horizon. Curtain antennas are mostly used by international short wave
radio stations to broadcast to large areas at transcontinental distances.