High-speed multiplexers: a 50 Gb/s 4:1 MUX in InP HBT technology

We have implemented a monolithic electronic 50 Gb/s 4:1 MUX core in an InP-based HBT technology. This rate is the fastest achieved in a monolithic 4:1 MUX to our knowledge, and is currently limited by the speed limitations of our pattern generation equipment. Our 2:1 MUX is too fast for characterization at present, but we present evidence that the speed of the 2:1 MUX is at least 60 Gb/s.