The insulation material of RF coaxial cables is composed of physically foamed polyethylene insulated copper wire conductors. The outer layer of the insulation material is another circular conductor, which is the outer conductor. The outer conductor (tissue shielding layer) is formed, welded, and tied with copper tape; Or use aluminum tube structure; Alternatively, a woven structure can be used, and the entire cable is wrapped in a PVC sheath. There are two types of commonly used RF coaxial cables: 50 Ω and 75 Ω RF coaxial cables. RF coaxial cables with a characteristic impedance of 75 Ω are commonly used in CATV networks, hence they are called CATV cables. The transmission bandwidth can reach 1GHz, and the transmission bandwidth of commonly used CATV cables is 750MHz. RF coaxial cables with a characteristic impedance of 50 Ω are mainly used for baseband signal transmission, with a transmission bandwidth of 1-20MHz. Generally, the maximum transmission distance of thin coaxial cables with a characteristic impedance of 50 Ω is 180 meters, while thick coaxial cables can reach up to 1000 meters. The name of RF coaxial cable is related to its structure. RF coaxial cables are also one of the most common transmission media in local area networks. The pair of conductors used to transmit information is selected based on a cylindrical outer conductor sheathed outside the inner conductor (a thin core), and the two conductors are isolated from each other using insulating materials. The center of the outer conductor and the central axis core wire are on the same axis, so it is called a radio frequency coaxial cable. The reason why the radio frequency coaxial cable is designed in this way is to prevent external electromagnetic waves from interfering with the transmission of abnormal signals. RF coaxial cables can be divided into coarse RF coaxial cables and fine RF coaxial cables based on their diameter. Thick cable is suitable for relatively large local networks, with long standard distances and high reliability. Due to the fact that cables do not need to be cut off during installation, the network access position of the computer can be flexibly adjusted according to needs. However, thick cable networks must install transceiver cables, which is difficult to install, resulting in high overall cost. On the contrary, the installation of thin cables is relatively simple and cost-effective. However, due to the need to cut off the cables during the installation process, basic network connectors (BNCs) must be installed at both ends, and then connected to both ends of the T-shaped connector. Therefore, when there are many connectors, it is easy to create adverse hazards, which is one of the most common faults that occur in running Ethernet. Both thick and thin cables are bus topologies, where multiple machines are connected to one cable. This topology is suitable for machine intensive environments, but when a contact fails, the fault will cascade and affect all machines on the entire cable. The diagnosis and repair of faults are very troublesome, therefore, they will gradually be replaced by unshielded twisted pairs or optical cables