Antenna is an essential part of wireless transmission, in addition to our use of fiber optics, cables, network cables, etc. to transmit wired signals, as long as the use of electromagnetic waves in the air to propagate the signal, are required in various forms of antennas. Today we will learn about the antenna according to the shape to understand the classification!
1) whip antenna
General work is not high, in the U/V band, there are many deformed forms, such as rod antenna, spring antenna, etc., automobile, wireless WIFI, walkie-talkie, etc. often use a kind of omni-directional antenna, gain is not high, generally within 10dBi, can also be more than one group array (SCT rod antenna) to achieve higher performance indicators.
2) Plate antenna
The most used antenna in mobile communication base station, the advantages of this kind of antenna are: high gain, good directional map of sector area, small back flap, easy to control the pitch angle of vertical plane directional map, reliable sealing performance and long service life.
3) Ceiling antenna
Generally used for indoor wireless coverage scene, according to its different radiation form, can be divided into directional ceiling antenna and omni-directional ceiling antenna, omni-directional ceiling antenna can be divided into unipolarized ceiling and dual-polarized ceiling two.
4) Yagi antenna / logarithmic periodic antenna
Yagi antenna is mainly used for link transmission and repeater, has the advantages of high gain, light structure, easy to set up, cheap and so on. The more units of antenna, the higher its gain, usually 6-12 units of yagi directional antenna, its gain can reach 10-15dBi. old TV receiving antenna is used yagi antenna. Logarithmic periodic antenna and yagi antenna is similar, by adjusting the frequency of each radiation unit, has a wide bandwidth coverage ability, mainly used for link relay, radio direction finding.
5）Parabolic antenna
Specialized in long-distance communication of high directional antenna, there is a very narrow beamwidth and high gain value, can also be called high gain directional antenna. There are also a variety of deformation, including front-feeding parabolic, back-feeding Cassegrain antenna, weight reduction and low-frequency use of the grid antenna. These antennas are typically used for point-to-point communication connections, where the antennas must be very precisely aimed at each other and the Light of Sight (LOS) between the antennas must be free of any obstructions.
We see the parabolic antenna has a large and small, small such as household "pot cover", large such as satellite receiving station diameter of more than ten meters "big pot cover", this size is called the caliber, the larger the caliber, the higher the antenna gain.
6) Planar Antenna
PCB antenna: PCB antennas are the most common planar antennas, which can be either a small piece or a small ring, spiral or linear. Their BOM cost is negligible, only need to occupy the PCB space, low cost, do not need to assemble the antenna separately, not easy to touch the damage, the whole machine is easy to assemble, but there is a price - the sacrifice of performance.
Dielectric ceramic antenna: Because the size of the antenna is related to the wavelength of the work, therefore, one of the disadvantages of PCB antenna is that if it needs to have better performance, the size will increase, dielectric ceramic antenna better solve this problem, dielectric ceramics dielectric constant is very high, occupies a small space of the size, the typical application is GPS and Bluetooth antenna.
Conformal antenna: planar antenna also has a significant advantage: if you use a flexible printed circuit board, you can make the antenna and the object surface close to the surface, and even make the antenna on the surface of the object, which gives rise to a conformal antenna, airplanes, missiles, and other surfaces can be used; combined with the laser engraving technology, you can make a conformal antenna on the cell phone shell (FPC antenna, LDS antenna).
7) Horn antenna
Horn antenna is a kind of microwave antenna, belongs to the surface antenna. Waveguide terminal gradient open circular or rectangular cross-section of the microwave antenna, its advantages are simple structure, wide bandwidth, large power capacity, easy to adjust and use. If the horn size is reasonably selected, good radiation characteristics can be achieved.
There are many subdivided categories of horn antennas, such as standard gain horn, conical horn, angle cone horn, double ridge horn, lens horn, corrugated horn and so on.