English: Diagram of an umbrella antenna, a toploaded wire transmitting antenna used in the medium frequency (MF), low frequency (LF) and very low frequency (VLF) bands. It consists of a steel mast (grey) insulated from the ground, with diagonal wires radiating from the top, anchored to the ground in a circle around it. The feedline from the transmitter is connected to the bottom of the mast. The wires have insulators (brown) in their lower part to prevent the voltage from reaching the ground. The vertical mast acts as the radiating antenna radiating the radio waves, and it's base is supported on a ceramic insulator (brown) to isolate it from the ground. The diagonal wires act as a capacitive topload, increasing the current in the mast, to increase the power radiated by the antenna. The wires also act as guy lines to support the antenna.