Coaxial cable is a type of electrical and signal transmission cable, typically consisting of four layers: at the core is a conductive copper wire, which serves as the central conductor. Surrounding it is a layer of plastic, acting as an insulator and dielectric. Outside the insulator is a thin mesh of conductive material (usually copper or alloy), serving as a shielding layer. The outermost layer is made of insulating material, which forms the protective outer sheath.
Development of Coaxial Cable:
Coaxial cables have evolved through four generations:
- The first generation, starting in the mid-19th century, used polyethylene materials as the solid core insulator.
- The second generation utilized chemically foamed PE materials as the insulating medium.
- The third generation employed longitudinally perforated PE materials as the insulating medium.
- The fourth generation adopted physically foamed PE materials for insulation.
Coaxial cables are also categorized by structure into: leakage coaxial cables, multi-core coaxial cables, small diameter coaxial cables, and composite coaxial cables.
The coaxial cable industry has gone through significant changes over time. As the global electronics industry reached its peak around the year 2000, the coaxial cable market, as part of the electronics sector, also reached an all-time high. However, in the following three years, as global economic growth slowed, the demand for coaxial cables shrank, leading the industry into a period of stagnation. It wasn’t until the second half of 2003 that signs of recovery appeared. Starting in 2004, the global coaxial cable industry entered a new growth phase. With the expanding coverage of mobile communications signals, the increase in base stations, and growing demands from sectors like transportation, energy, and healthcare, the global RF coaxial cable industry is poised for strong market growth.
Coaxial Cable Types:
- RG-8, RG-9, RG-11:All have an impedance of 50Ω and are used for thick cable Ethernet.
- RG-58:Impedance of 50Ω, used for thin cable Ethernet.
- RG-6, RG-59, RG-75:Impedance of 75Ω, used for television systems.
- RG-62:Impedance of 93Ω, used for ARCnet networks and IBM 3270 networks.
Main Applications of Coaxial Cables:
- TV Signal Transmission:Coaxial cables are the preferred choice for transmitting television signals, ensuring clarity and stability.
- Telecommunication:Coaxial cables can be used to connect user terminals to telephone exchanges or devices, offering long transmission distances and excellent anti-interference capabilities.
- Security and Surveillance:In the security field, coaxial cables are used to transmit video signals, including images and sounds captured by cameras.
- Radio Communication:In radio communication, coaxial cables are used for transmitting high-frequency signals, such as radio broadcasts, television signals, and satellite communication.
- Internet Access:Coaxial cables are used in broadband signal transmission for services like ADSL and cable modems.
- Aerospace:In aerospace, coaxial cables are used for transmitting critical signals like radar, navigation, and communications.
Please note that while coaxial cables offer many advantages, they also have limitations, such as signal attenuation and noise interference, which may need to be considered for long-distance transmission.
Naming Convention of Coaxial Cables:
The first part of the name uses letters to represent the cable's code, core insulation material, sheath material, and derived features.
The second part uses numbers to indicate the cable’s characteristic impedance (Ω).
The third part uses numbers to represent the outer diameter of the cable’s core insulation (mm).
The fourth part uses numbers to indicate the cable’s structural sequence.
Naming Convention for RG Coaxial Cables (According to Military Standard MIL-C-17F):
-
RG-58A/U
- RG: Radio frequency coaxial cable
- 58: Cable number
- A: Revision version
- U: General specifications
