beam forming network (BFN)

This term is defined in ECSS-E-ST-20C as
“wave-guiding structure composed a chain of microwave components and devices (lines, phase shifters, couplers, loads) aimed at distributing the RF power injected at the input ports to a number of output ports; in a transmitting antenna the RF power injected from the transmitter is routed to the radiating elements, in a receiving antenna the RF power coming from the radiating elements is routed to the antenna ports connected to the receiver