English: Three types of
inverted L antennas. The inverted L is a capacitively top-loaded wire
monopole antenna antenna used at lower frequencies below 20 MHz. The name comes from its shape, the wires are in the shape of a letter "L" on its side. It is similar to a
T antenna, except that the vertical feeder wire, instead of being attached to the center of the horizontal wire, is attached at one end. There is a radial wire
ground system consisting of buried wires radiating outward from under the antenna
(not shown). Unlike the
omnidirectional T antenna, the inverted L is a
directive antenna, it's
radiation pattern has a main lobe, it emits maximum radio power horizontally in the direction of the topload wire, off the end with the feeder attached
(the left side in the drawing).
The drawing shows three common types. The single wire inverted L
(D) is often used for receiving. The multiwire flattop
(E) has multiple topload wires parallel to ground, giving it greater capacitance to ground, increasing the radiation resistance and radiated power at low frequencies. The cage inverted L
(G) distributes the current more equally between the wires, reducing the resistance. The multiwire versions are often used for transmitting antennas.