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Built in Antenna, External Antenna, Sucker Antenna, So Many Kinds of Antennas? Don't Make A Mistake!

Antenna is a kind of equipment that radiates RF signals from the coaxial cable to the air or receives them from the air to the coaxial cable. It converts the guided traveling wave scattered on the coaxial cable into radio waves scattered in unbounded media, or vice versa. If you choose wrong, you will not get the proper function, and even burn the module seriously
For the design scheme, a wireless network receiving and transmitting machine and equipment used in the frequency radio system software, the design scheme and selection of antenna is a key part. Excellent antenna system software can optimize the communication spacing. The size of the same kind of antenna is positively related to the optical wavelength of RF signal. The lower the frequency of data signal, the larger the antenna required.
01. Classification of antenna antenna can be divided into external antenna and internal antenna by the installation position. The antenna installed inside the machine and equipment is called internal antenna, and the antenna installed outside the machine and equipment is called external antenna.
The built-in antenna is widely used for small-size commodities such as hand-held machinery and equipment, wearing design scheme and smart home system, with high processing speed and beautiful appearance. Internet of things technology, intelligent products and commodities must be connected to the network to transmit data, so antennas must be used.
The smaller the indoor space and the more frequency bands, the more complicated the antenna design scheme. The external antenna is generally all standard materials. The antenna in the required frequency band can be used without adjustment.
For example, for express boxes and vending machines, external antennas widely used for magnetic absorption can be absorbed on the white iron casing. This kind of antenna can not be placed in the iron file cabinet, and the metal material will shield the antenna data signal, so it can only be placed outside. This paper introduces the basic information of the antenna in detail from the classification and model selection of the antenna.
1.1 external antenna
The external antenna can be divided into omnidirectional antenna and fixed term antenna according to the different viewing angles and orientations of the radiation source field and the radiation source.
Omnidirectional antenna indoor space radiation diagram
Omnidirectional antenna: in the horizontal pattern, it is mainly characterized by 360 ° uniform radiation source, that is, it is often said that there is no specificity. In the vertical pattern, it is mainly characterized by a beam with a certain total width. Generally, the smaller the total width of the lobe, the greater the gain. The key components of external omnidirectional antenna include glass sucker antenna, FRP anti-corrosion antenna and hot-melt adhesive rod antenna.
Indoor space radiation diagram of fixed term antenna
Fixed term antenna: refers to an antenna that is particularly strong in transmitting and receiving radio waves in one or more special directions, while zero or very small in transmitting and receiving radio waves in other directions. The purpose of selecting fixed term transmitting antenna is to improve the reasonable utilization rate of radiation intensity and safety; The key purpose of selecting fixed term receiving antenna is to improve receiving sensitivity and anti-interference. The key of external fixed term antenna includes tablet antenna, Yagi antenna and most cycle time antenna.
1.2 built in antenna
The key of built-in antenna refers to the antenna that can be placed inside the machine and equipment. The key of built-in antenna includes FPC antenna, PCB antenna, spring antenna, porcelain patch antenna, laser immediate forming technology (LDS) and hardware spring antenna.
02. When selecting suitable antennas for machines and equipment in the model selection manual, the built-in or external antennas shall be clearly adopted according to the product structure. The main characteristics of the external antenna and the built-in antenna are as follows:
External antenna
High gain, little environmental harm, can be used as a standard product, save development progress, occupy indoor space and endanger the beauty of goods
Built in antenna
High gain relativity, perfect processing technology, good consistency of goods delivery, built in machinery and equipment, beautiful and generous, no independent three prevention, great harm to the surrounding environment, and generally must be customized by integrating the goods themselves
2.1 model selection of external antenna
Firstly, the coverage area of data signals of machinery and equipment must be defined. The coverage orientation of data signals is determined by the radiation source pattern of the antenna. According to the radiation source orientation of the antenna, the antenna is divided into omni-directional antenna and fixed term antenna.
2.1.1 external omnidirectional antenna
Glass sucker antenna: the gain is relatively high, and the larger characteristic is that it contains a strong magnet. It is very convenient to install and fix the glass sucker, but the glass sucker must be absorbed on the metal surface. In the field of wireless modules, glass sucker antennas are often used in cooperation with wireless modules, so as to achieve the purpose of improving the communication distance of wireless modules, such as wireless intelligent meter reading, vending machines, express boxes, on-board radios, etc.
Copper rod glass sucker antenna: it is similar to the general whip glass sucker antenna, but its advantages over the whip glass sucker depend on the selection of all copper radiator with large diameter, low European Bus loss, high antenna efficiency and wide network bandwidth. It is applicable to data transmission radio stations with high relativity specified for performance, picture transmission with medium horizontal spacing, etc.
Hot melt adhesive rod antenna: it is the most common external antenna with moderate gain and relatively cheap price. It is commonly used in wireless communication control module, wireless router, data transmission radio station, etc. The antenna with suitable specification and size can be selected according to the provisions of the installation indoor space. The selection of antenna specification is related to the gain. Generally, the longer the length of the same frequency band, the higher the gain.
FRP anti-corrosion antenna: among omni-directional antennas, the performance of FRP anti-corrosion antenna is more excellent, in which the core is all copper vibrator and balanced explosion-proof switch is selected, which is less harmful to the environment; The casing is made of high-quality FRP for anti-corrosion. It has very good three prevention characteristics and is well integrated into the extreme geographical environment. It is especially suitable for ultra long distance gateway, IP data signal masking, image transmission, etc.
2.1.2 external directional antenna
It is generally used in the natural environment with long-distance communication, small data signal coverage and high overall target density. The extreme example is point-to-point long-distance communication.
Tablet antenna: high efficiency, light volume, convenient installation, capable of both gain and radiation source area. It can be covered by network signals in the room and tunnel construction, data signal transmission with medium horizontal spacing, map transmission and data signal passing through the wall.
Yagi antenna: very high gain, slightly large volume and strong specificity. Pay attention to the orientation of the antenna during application. It can be used for ultra long-distance data signal transmission, map transmission and direction finding.
Most cycle time Antennas: ultra wideband antenna. The network bandwidth coverage is very wide, and the network bandwidth can reach 10:1. It is common that the data signal becomes larger, and the data signal of elevator car is covered all over the room.
2.2 model selection of built-in antenna
The shape of the built-in antenna can be divided into: FPC / PCB / spring / porcelain / hardware spring / laser immediate forming technology (LDS). At this stage, PCB antenna is generally selected. Under the condition of high cost management and general performance regulations, the spring LDS antenna shall be selected. The general built-in antenna is subject to environmental hazards, and the design scheme or matching resistance must be customized.
FPC antenna: with excellent performance price ratio, it can be consistent with various appearance colors after oil pump; The product has good flexibility, which can perfectly meet the standard arc surface; Perfect and stable processing technology, fast production cycle and good mass delivery; It is applicable to the antenna design scheme of broadband intelligent products with high performance.
PCB antenna: the big difference between FPC antenna and FPC antenna is that FPC has very good flexibility. PCB antenna is a hard board. In terms of structure and installation, if it must be bent and its curved surface, FPC antenna can be selected. If it is a plan view, PCB antenna can be selected. PCB antenna is easier to install than FPC.
Spring antenna: it has the characteristics of low price, low gain and band width. When it is built in the commodity, the antenna pairing must be adjusted.
Porcelain patch antenna: it occupies little indoor space and has good performance; Band width, it is difficult to ensure multiple frequency bands; Reasonably improve the integration degree of computer motherboard and reduce the limit of antenna on ID; The design scheme must be introduced at the beginning of the definition of the computer motherboard.
LDS antenna: it is applicable to the antenna with unique appearance and can flexibly use the indoor space of the antenna; The completion of antenna performance is closer to the physical limit of natural environment; There are unique material provisions for the shell or support frame to which the antenna is attached; The processing technology is perfect, and there is a certain unqualified rate in the whole process according to the paint color.
Hardware Spring antenna: with high cost performance and reasonable cost control; The product has high compressive strength and is not easy to be damaged; Perfect and stable processing technology, fast production cycle and good mass delivery; The application of antenna area and arc surface has certain limitations.