The coaxial cable is one of the most widely used today as it has a wide variety of applications in the communications field. Broadly speaking, it is used to carry radio and video signals as well as measurement signals and data. Thus, it is very interesting to analyze the coaxial cable in detail.
What is coaxial cable?
This is an insulated core conductor that is covered with a shield. Therefore, the signal is transmitted between the cable guard and the core conductor. This hermetic seal allows the external cable noise to be addressed and ensures a stable environment.
Of course, the coaxial cables and systems connected to them are not always in optimal condition. In the vast majority of cases there is a certain signal emitted by the coaxial cable itself. Thus, the external conductor also acts as a protector to reduce the signal coupler in the adjacent wiring. It is worth bearing in mind that greater coverage of the protector means less energy radiation.
There are two common characteristics of the coaxial cable: impedance and cable loss. In the case of the usual coaxial cable, the impedance depends on the size of the internal and external conductors.
What types of coaxial cables are there?
Today, most of the usual impedances of coaxial cable operating in various applications are 50 ohms and 75 ohms.
50 ohms
The 50 ohms of coaxial cable are used by nearly 100% of the radio transmitters. It allows the transmitter antenna to be optimally paired with each other and allows the transmitter’s high power output to be easily controlled. The 50 ohms of coaxial cable are also increasingly being used in coaxial Ethernet networks.
60 ohms
In Europe, the 60 ohms of coaxial cable were most common in radio systems of the mid-1950s; they were used in transmission antenna networks.
75 ohms
This impedance is a global standard and has been developed from optimizing the design of intercity coaxial cables. It is mainly used in video, audio and telecommunications.
93 ohms
This impedance is no longer used today. In their time they were used for short runs, such as the connection between different computers and their respective monitors. It was also used in some digital communication systems, as well as the first LAN systems in history.
The usual impedance of a given connector is determined by the relationship between the diameter of the outer conductor and the diameter of the inner conductor, as well as by the dielectric constant of the insulation. Also, keep in mind that this can vary with frequency. This is all we can tell you about the coaxial cable in detail. If you need more information, do not hesitate to contact us.