Preferably the common nodes (608, 609) have no additional electrical connection to the amplifier unit.
优选地，公共节点(608,609)没有到放大器单元的额外电连接线。
2
If necessary, the area can be extended by adding additional repeater units, all connected to the same external antenna, using a signal splitter and line amplifier.
The output amplitude and the length of pulses train are greatly improved with additional semiconductor optical amplifier and filter in the optical fiber loop as the DC component of input keeps low.