Q.What is an Antenna? Briefly explain any four types of Antennas.

An antenna is a device that radiates and receives electromagnetic waves, converting guided electrical energy into radiated waves at the transmitter and vice versa at the receiver. Common types include the helical, Yagi, loop and horn antennas. …

[!TLDR]

An antenna is a device that radiates or receives EM waves; four common types are the helical, Yagi, loop and horn antennas.

What is an antenna: An antenna is a device that radiates and receives electromagnetic waves. It converts the high-frequency electrical energy from a transmitter into electromagnetic waves for radiation into space, and at the receiving end it intercepts electromagnetic waves and converts them back into electrical signals. Antennas are necessary for television, satellite broadcasts, radio broadcasting and cellular telephone communication, and they come in many shapes and sizes according to their purpose.

Four types of antennas:

1. Helical Antenna: It consists of a conducting wire wound in the form of a helix (coil), usually mounted over a ground plane. It radiates along the axis of the helix and is commonly used at earth base stations in satellite communication systems.

2. Yagi Antenna: It is an array of parallel, straight antenna elements mounted along a boom, with one or more driven elements and one or more parasitic elements (a reflector and directors). The parasitic elements make it highly directional, so it is also called a beam antenna; it is widely used for television reception. The name honours the Japanese researchers Yagi and Uda.

3. Loop Antenna: It is a loop of conductor wound on a form (a box or spiral), with an air or powdered-iron core. Its gain is much less than that of a long-wire antenna, but it picks up much less noise, and a properly designed loop responds primarily to the magnetic component of the radio wave. It is used where efficient, low-noise reception and direction finding are needed. …