Radio over fiber (RoF) is an analog transmission method that uses RF signals to modulate light, which is then transmitted through optical fibers. RoF technology has been widely used in avionics, distributed antennas, cellular telephones, satellite communications, and other fields. This is a low. RF-over-fiber modules transport RF signals over optical links to reduce coax loss and extend distance, using linearized transmit/receive optical chains. These modules combine the functionality of both a transmitter and a receiver into a single unit, enabling bidirectional communication.