Antennas are an essential part of wireless transmission. In addition to using fiber optics, cables, network cables, etc. to transmit wired signals, various forms of antennas are required for any signal propagated by electromagnetic waves in the air. Today, let's learn about the classification of antennas based on their appearance!
 

1) Whip antenna
Generally, the work is not high. In the U/V band, there are many variations, such as rod antennas, spring antennas, etc. It is a commonly used omnidirectional antenna in automobiles, wireless WIFI, walkie talkies, etc. The gain is not high, usually within 10dBi. It can also achieve higher performance indicators through multiple arrays (pager rod antennas).
 

2) Plate antenna
The most commonly used antenna in mobile communication base stations has the advantages of high gain, good fan-shaped directional pattern, small back lobe, convenient control of vertical directional pattern depression angle, reliable sealing performance, and long service life.
 

3) Ceiling mounted antenna
Generally used in indoor wireless coverage scenarios, directional ceiling antennas and omnidirectional ceiling antennas can be classified according to their different radiation forms. Omnidirectional ceiling antennas can be further divided into single polarization ceiling antennas and dual polarization ceiling antennas.
 

4) Yagi antenna/logarithmic periodic antenna
Yagi antenna is mainly used for link transmission and relay, with advantages such as high gain, lightweight structure, easy installation, and low price. The more elements an antenna has, the higher its gain. Typically, a 6-12 element Yagi directional antenna is used, which can achieve a gain of 10-15 dBi. The old TV receiver antenna uses an Yagi antenna. Logarithmic periodic antenna is similar to Yagi antenna, which has wideband coverage capability by adjusting the frequency of each radiating element. It is mainly used for link relay and radio direction finding.
 

5) Parabolic antenna
A high directional antenna specifically designed for long-distance communication, with an extremely narrow beamwidth and high gain value, also known as a high gain directional antenna. There are also various variations, including feedforward parabolic antennas, feedback Cassegrain antennas, and grid antennas used for weight reduction and low-frequency applications. This type of antenna is typically used for point-to-point communication connections, where the antennas must be aimed precisely at each other and there must be no obstacles in the light of sight between the antennas.
The parabolic antennas we see come in various sizes, ranging from small ones like a household "pot cover" to large ones like a satellite receiving station's "big pot cover" with a diameter of over ten meters. This size is called the aperture, and the larger the aperture, the higher the antenna gain.
 

6) Flat antenna
PCB antenna: PCB antenna is the most common planar antenna, which can be small pieces or loops, spiral or linear. Their BOM cost can be ignored, only occupying PCB space, low cost, no need to assemble antennas separately, not easy to touch and damage, easy to assemble the whole machine, but at a cost - sacrificing performance.
Dielectric ceramic antenna: Due to the size of the antenna being related to the operating wavelength, one of the disadvantages of PCB antennas is that if better performance is required, the size will increase. Dielectric ceramic antennas solve this problem well. Dielectric ceramics have a high dielectric constant and occupy a small size space. Typical applications are GPS and Bluetooth antennas.
Conformal antenna: Flat antennas also have a significant advantage: if flexible printed boards are used, the antenna can be tightly attached to the surface of the object, and even manufactured on the surface of the object, thus creating a conformal antenna that can be used on surfaces such as airplanes and missiles; By combining laser engraving technology, conformal antennas (FPC antenna, LDS antenna) can be made on mobile phone cases.