V-Band Two-Stage Converters With Optical Fibre Connectivity. The two-stage converter is designed for compact hubs, which often have limited space directly at the antenna and only a compact outdoor unit can be accommodated. For the upconversion path, the first conversion stage is an indoor unit that then passes the signal via optical fibre into the compact second stage (e.g., V-Band converter) — almost loss-free even over longer distances with several hundreds of meters. For the down-conversion, the inverse scheme applies.