Cables—everyone is probably familiar with them, but how many people are familiar with radio frequency cables? Simply put, they're essential components in all kinds of radio communications and electronic devices we use. Today's article will focus on what radio frequency cables are and their classifications.
RF Cable Overview
RF cables are cables that transmit electromagnetic energy in the radio frequency range. They are essential components in various radio communication systems and electronic devices, and are widely used in wireless communications, broadcasting, television, radar, navigation, computers, and instrumentation.
Cable Function: Cables are used to transmit radio frequency (RF) signals. They minimize emission losses and provide protection against electromagnetic interference, allowing signals to be transmitted over longer distances with minimal power consumption. Coaxial cable consists of a core, insulation, shielding, and outer jacket. It's called coaxial because these sections all share the same axis. There are many different types of coaxial cables, each with different physical and electrical characteristics designed for specific tasks. They are commonly used to carry cable television signals along suburban streets and within homes.
RF cables are classified by structure
(1) Coaxial RF cables
Coaxial RF cables are the most commonly used structural type. Since the inner and outer conductors are in concentric positions, the electromagnetic energy is confined to the medium between the inner and outer conductors. Therefore, they have significant advantages such as low attenuation, high shielding performance, wide operating frequency band and stable performance. They are usually used to transmit RF energy from 500 kHz to 18 GHz.
Currently, there are two types of commonly used RF coaxial cables: 50Ω and 75Ω RF coaxial cables. RF coaxial cables with characteristic impedance of 75Ω are often used in CATV networks, so they are called CATV cables. The transmission bandwidth can reach 1GHz. The transmission bandwidth of commonly used CATV cables is currently 750MHz.
(2) Symmetrical RF cables
The electromagnetic field of the symmetrical RF cable loop is open. Since there is radiated electromagnetic energy at high frequencies, the attenuation increases and the shielding performance is poor. In addition, due to the influence of atmospheric conditions, they are usually rarely used. Symmetrical RF cables are mainly used in low RF or symmetrical feeding situations. (3) Spiral RF Cable
The conductor in a coaxial or symmetrical cable can sometimes be made into a spiral coil to increase the inductance of the cable, thereby increasing the wave impedance of the cable and delaying the transmission time of electromagnetic energy. The former is called a high-resistance cable, and the latter is called a delay cable. If the density of the spiral coil is different along the length direction, a variable resistance cable can be made.
RF Cable Applications:
Longitudinal-hole polyethylene insulated coaxial cable suitable for use as branch lines and users of closed-circuit television, common antenna television systems, and other electronic devices.
The above is the information collected by the editor on the classification and use of RF cables. In short, RF cables have strong performance. Everyone must correctly understand RF cables and use them correctly. In the future, its scope of application will become more and more extensive. It is better to have a simple understanding of it, which will also provide more reference value for everyone to use RF cables in the future.
