English 
The growth of wireless and high-speed data applications has led to the use of coaxial cables over traditional video and telecommunication cables. With the development and standardization of coaxial cables used in various applications, coaxial cables have become common equipment in homes, offices, telecommunications facilities, railways, industrial plants, and government/public safety facilities. The diversification of such applications has led to the diversification of coaxial cable types, grades, and manufacturers.
The following suggestions and common problems will help you make the right choice when purchasing coaxial cable according to your specific needs.
The beginning of everything is always to understand the problems to be solved. For the purchase of coaxial cable, this means that you need to understand the quality of the signal that the cable needs to carry. Some of the important factors are the frequency range and the power level of the transmitted signal. Other factors include the RF and electromagnetic environment through which the signal passes, the length of wiring, and the difficulty of wiring. Regarding the specific coaxial cable selected for an application, the project budget and all institutional requirements also play an important role in decision-making.
The two main impedances used for coaxial cables are 75 ohms and 50 ohms. Unless there is visible content of the logo, the impedance of a coaxial cable cannot be judged from the outside. If the above two impedances are confused, it may cause damage to the device connector or the device itself, or at least degrade the performance of the system. Although sometimes used crosswise, 75-ohm coaxial cables are commonly used for video applications, while 50-ohm coaxial cables are more commonly used for data and wireless applications. The type of equipment and devices that need to be connected determines the impedance of the cable used.
Signal energy can be lost due to thermal energy caused by conductor resistance, dielectric loss factor, and other factors related to the quality of coaxial cable materials. The attenuation of a coaxial cable represents the energy loss per unit length of cable. For applications where signal power is extremely low or wiring requirements are extremely long, and no amplifier or signal booster is provided, low-loss cables may be required to meet the minimum signal strength requirements at the receiving end of the coaxial cable. If the attenuation of the coaxial cable is so low that no signal booster is needed, even if the low-loss cable is more expensive, the use of the cable is still a cost-effective investment.
