Types of Wireless Antennas
In the field of electronics, the definition of antenna is “transformer / transmission structure between guided waves (transmission channels) with free space waves or vice versa. Now the antenna is one of the essential elements that must be present in a radio telescope, TV, radar, and all other means of communication that use signals.” An antenna is a vital part of a transmitter or receiver that serves to transmit radio signals into the air. The shape of the antenna varies according to the design, distribution pattern and frequency and gain. The antenna length is effectively the wavelength of the radio frequency it emits. Half-wave antennas are very popular because they are easy to manufacture and can transmit radio waves effectively.
The function of the antenna is to convert the electrical signal into an electromagnetic signal, then radiate it (release of electromagnetic energy into the air / free space). And vice versa, the antenna can also function to receive electromagnetic signals (receiving electromagnetic energy from free space) and convert them into electrical signals.
Antenna radiation pattern is a 3-dimensional plot of the distribution of the signal emitted by an antenna, or a 3-dimensional plot of the reception level of the signal received by an antenna. The antenna radiation pattern is formed by two radiation patterns based on the plane of slices, namely the radiation pattern in the plane of the slice in the elevation direction (elevation pattern) and the radiation pattern on the plane of the slice in the azimuth direction (azimuth pattern).
Gain (directive gain) is an antenna character related to the antenna’s ability to direct its signal radiation, or receive signals from a certain direction. Gain is not a quantity that can be measured in common physical units such as watts, ohms, or others, but a form of comparison.
Polarization is defined as the direction of propagation of the electric field. The dipole antenna has a vertical linear polarization. Recognizing the polarization of the antenna is very useful in communication systems, especially to get maximum efficiency in signal transmission.
antenna for wireless
- Omnidirectional Antenna
An omnidirectional antenna is a system power antenna that radiates uniformly in one plane with a directional pattern in a perpendicular plane. This pattern is often described as “donut shaped”. This pattern is often described as “donut shaped”. Omnidirectional antenna can be used to link multiple directional antennas in outdoor point-to-multipoint communication systems including cellular phone connections and TV broadcasts. Omnidirectional antennas can be used to connect multiple directional antennas in outdoor point-to-multipoint communication systems including cellular telephone connections and broadcast TV.
Omnidirectional antenna, which is a type of antenna that has a pattern of transmitting signals in all directions with the same power. To produce a wide coverage area, the gain of an omnidirectional antenna must focus its power horizontally (horizontally, ignoring the upward and downward transmitting pattern, so that the antenna can placed in the middle of the base station. Thus, the advantage of this type of antenna is that it can serve a larger number of users. However, the difficulty is in allocating the frequency to each cell so that interference does not occur. This type of antenna is usually used in a wide range. has limited base stations and tends to broaden subscriber positions.
- Sectoral Antenna
Sectoral antennas are almost similar to omnidirectional antennas. Which is also used for Access Point to serve a Point-to-Multi-Point (P2MP) links. Some sectoral antennas are made perpendicular, and some are horizontal. Sectoral antennas have much higher gain than omnidirectional antennas at around 10-19 dBi. Which works at a distance or area of 6-8 km. The beam angle of this antenna is 45-180 degrees and the height of its installation must be considered so that there is no loss in signal capture.
The horizontal beam pattern mostly radiates in the direction where the antenna is directed according to the range of the degree of radiation, while at the back the antenna does not have a beam signal. This sectoral antenna, if installed higher, will benefit good reception in a sector or region of the beam that is wider. has been determined.
- Antenna Grid
The angle of this antenna beam pattern is more focused on a certain point according to its installation.
Parabolic Grid antenna for use in 802.11b/g/n WLANs. This high performance 2.4 GHz antenna is designed for years of rugged outdoor operation.