Single coaxial cable bidirectional drive circuit diagram

Generally, coaxial cable communication uses a dual-cable system, with one cable sending and one cable receiving. If a single cable transmission method is used, one cable can be saved, but this is only easier to implement for audio signals. For signals with a frequency of several MHz, it is difficult to use a high-speed amplifier and solve the impedance matching problem. very difficult. This circuit can provide bidirectional driving function for a single coaxial cable. According to the values ​​marked on the components in the figure, it is suitable for 50 ohm systems. After slight improvements, it can be suitable for 75 ohm systems.