What is coaxial cable and what are the advantages of coaxial cable?
Nov 11, 2020
From the structure diagram of the coaxial wire，It can be seen that from the inside to the outside are: the center copper wire, the insulating layer, the outer conductor layer (metal braided shielding net), and the jacket. Coaxial wire has two conductors with different structures. The center copper wire is used to transmit signals, and the metal shielding net plays two roles: One is to provide a current loop for the signal as a ground wire; the second is as a signal shielding network to suppress electromagnetic interference, so the single coaxial cable we see is not a single conductor, but a loop.
What is coaxial cable?
Because the outer metal braided shield and the central copper wire, as well as the inner and outer insulating layers are all on the same axis, so it is called coaxial wire
Common applications for coaxial cables are as follows:
1. Inside the machine (40~46AWG):such as drone and video surveillance (used to connect cameras that need frequent swinging), dual screen mobile phones and laptops that need to be bent, B-ultrasound probe, etc., which mainly uses the characteristics of coaxial wire that is super soft, thin and resistant to 100000 bends;
2. Outside the machine (28~36AWG): USB4, VR/AR, Thunderbolt 3, Thunderbolt 4 cables, DisplayPort 2.0, HDMI2.1, cables, mainly using coaxial cables with very low high-frequency impedance characteristic;
What are the advantages of coaxial cable compared to stranded cable?
Stranded cable is a traditional signal transmission mode. The high-frequency impedance of the stranded cable has a large difference in the range of plus or minus 10%, and the coaxial wire can be plus or minus 3%. Theoretically, USB4 can use stranded cables, but in the actual production process, it will be very difficult for the stranded cables to meet the requirements
1. The coaxial cable is super soft;
2. Bending resistance: the swing life can be more than 5000 times, and the stranded wire is about 3000 times (the number of bending resistance of the coaxialcable is less than that of a single coaxial wire);
3. Small diameter; the traditional stranded wire, a loop is twisted together by two wires, which is almost equivalent to two wires side by side, but the coaxial wire uses the shielding layer as its loop, and the diameter is only slightly larger than a single wire. the diameter is much smaller than the stranded wire with two wires side by side;
Disadvantages of coaxial cables:
1. Expensive: Because each high-frequency signal wire needs a separate braided shielding layer, the production efficiency is low, and the more expensive Teflon is used to replace the original PE insulation material;
2. The processing technology is complicated: because the conductor is very thin, when stripping the inner and outer insulation layer and the metal braidof the core wires , cannot use traditional machines, but use laser cutting;
With the advent of 5G even 6G big data era, high-speed data transmission requires high bandwidth and high speed. Only coaxial cable can meet this requirement. Coaxial cable will be the trend of the next generation of high-speed cables.