1. Directionality: that is, signals can only be transmitted from the main input end to the branch output end, but not from the branch output end to the main output end.
2. Isolation: As long as the main output port is connected with coaxial cable or terminal matching resistance with standard impedance, branch opening or short circuit has little effect on the input port network. CATV network uses this feature to connect the main input port of the user terminal.
