A monopole antenna is a type of radio antenna that consists of a single rod or wire, typically mounted vertically above a ground plane. This design allows it to radiate radio waves efficiently, making it popular for various applications, including cellular communication and broadcasting. The ground plane acts as a reflector, enhancing the antenna's performance by improving its radiation pattern. Monopole antennas are often easy to construct and can be made from simple materials, making them cost-effective. They are commonly used in mobile devices, vehicles, and base stations due to their compact size and ability to operate over a range of frequencies.