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 effectively transmit and receive radio waves. Monopole antennas are commonly used in various applications, including cellular communication, broadcasting, and wireless networks. The ground plane acts as a reflector, enhancing the antenna's performance by improving its radiation pattern. Monopole antennas are popular due to their simplicity, compact size, and ease of installation. They are often found in devices like mobile phones and transmitters for efficient signal transmission.