Antenna is a common term that we all have heard many times. It is used in several devices at commercial and residential places. Antenna helps to change electric power into electromagnetic waves.
In this article, we will cover the meaning of antenna, functions of antenna, benefits, and kinds of antennas. We will also discuss many other things related to antenna.
What is an Antenna?
Before we discuss the benefits and functions of the antenna, let us know the meaning of the antenna. It is a metallic tool that helps to send radio EM waves. The antenna is used either as a receiving antenna or transmitting antenna.
Antennas can be used in various electronic systems that need signal transmission. They work with radio waves that pass from one point to another.
Basic Function of the Antenna
Now, let us have a look at how the antennas work. To understand the working of an antenna, it is necessary to know the parts of an antenna. It is a kind of metal device that transmits radio frequency waves from one point to another in space.
A high voltage in a transmitting antenna produces radio signals that travel to a receiving antenna. In this antenna, the signal is turned again into electrical energy. Some of the main characteristics of an antenna are:
Radiation pattern of the antenna is shown with the help of quantity Field Strength. Antenna emits radio waves only in one direction while the energy sent in other areas is negligible.
Radiation intensity of an antenna is measured as the radiated power to input power. Efficiency of an antenna depends on the quality of materials used in making it. The quality of materials affects the performance of an antenna.
Antennas work under different frequencies. Bandwidth of antenna is the fixed set of frequencies at which aerial characteristics are maintained under a certain value.
Input impedance of an antenna is the amount of opposition mounted against the current flow via its conductive materials. Antenna will only work effectively when there is sufficient input impedance to its input transmission line.
The direction in which the electromagnetic waves are emitted in antenna is polarization. In the case of antenna that emits radio waves in different directions, the direction of maximum gain is used to show polarization.
Aperture is the terms used in a receiving antenna. Aperture in an antenna is the ability of an antenna to produce relevant signals from electromagnetic waves.
Why do we need Antennas?
Antennas are used in various electronic systems such as radio and TV. They are used for various tasks such as transmitting and broadcasting. Apart from that, the antennas also give many other benefits such as:
1. Increases range of operation
One of the major benefits of using an antenna in any device is that it increases the range of operation. It also improves the quality of communication and helps network providers to provide the coverage at low cost.
2. Increases number of users on the same frequency
Antennas will increase the number of users on the same frequencies. More users will decrease the operating costs of network providers. Antenna is a cost-effective tool to provide more coverage at low costs.
3. Increases the bandwidth
Antenna increases bandwidth in the frequencies. It also strengthens the signals to reach the device and improves performance as well.
Types of Antennas
Log-Periodic Antennas
This directional antenna type contains multiple elements that run over many frequencies. A log periodic antenna is a kind of dipole arranged in line with axis. These antennas are used in many devices that need variable bandwidths and antenna directivity.
Bow-Tie Antennas
A Bow-tie antenna contains triangular elements and not straight rods as the antenna elements. These triangular elements are stuck on both sides of the antenna and have a shape like of a bow tie. The wings of this antenna are symmetrical on both sides.
Log-Periodic Dipole Array
Log periodic dipole array antenna has many half-wave dipole elements of increasing length. These elements contain metal rods and the dipoles are connected close together in a line. LPDA looks similar to Yagi-Uda antennas.
Short Dipole Antenna
As the name suggests, this antenna has shorter length of wire than the length of wavelength. Voltage source is attached to one end of the antenna and the lines are terminated at the other end.
Dipole Antenna
Dipole antenna is a type of antenna that contains 2 same conductive materials like rods and metal wires. Driving current from the transmitter is applied to receive or transmit the signals. This is an antenna that generates radiation patterns that are similar to elementary electric dipole.
Monopole Antenna
Monopole antenna is a radio antenna containing a straight rode like conductor. It is mounted above the ground surface and has simple design. It contains a single wire that helps to transmit and receive signals in wireless systems.
Loop Antenna
Loop antenna is a versatile antenna that has a simple design. It is cost-effective antenna that comes in various shapes such as triangular, elliptical and circular. This antenna is used in devices where the microwave bands up to 3 GHz.
Helical Antennas
Helical antenna includes a single metal conductor wound that has a helical shape. Circular polarization is one of the unique features in helical antennas. They also have both vertical and horizontal radio wave patterns.
Parabolic-Reflector Antenna
Parabolic reflector antenna contains a parabolic reflector to direct the radio waves. These antennas have a shape like of a dish. This antenna is also known as parabolic dish or dish antenna. They are widely used in televisions and broadcasting purpose.
Final words
These are the characteristics, benefits and types of antennas. Antenna is widely used in communication and broadcasting purposes. It is also used in a variety of electronic systems such as mobile phones, TV and radios. Antennas will continue to evolve year after year with technology.