Active and Passive Relay Station

　Radio Frequency relay station
　An active, bi-directional radio repeater system without frequency shift. The RF relay station directly amplifies the signal over radio frequency.

　Regenerator relay station
　A high-frequency repeater of high performance. The regenerator relay station is used to extend the transmission distance of microwave communication systems, or to deflect the transmission direction of the signal to avoid obstructions and ensure the signal quality is not degraded. After complete regeneration and amplification, the received signal is forwarded.  

Parabolic reflector passive relay station

The parabolic reflector  passive relay station is composed of two parabolic antennas connected by a soft waveguide back to back.

The two-parabolic passive relay station often uses large-diameter antennas. Meters are necessary to adjust antennas, which is time consuming.

The near end is less than 5 km away.