Six-port and five-port receivers for UWB and optical communications

Some achievements on multiport direct conversion receivers at microwave and optical frequencies are reported. Several sixport junctions with full UWB band (3.1–10.6 GHz) coverage will be presented and compared which, due to their low imbalances, allow to develop a six-port direct conversion receiver with analog I/Q recovery for the complete UWB band. On the optical side, six-port based receivers have found wide acceptance as coherent receivers for 100Gbit/s communications based in QPSK and higher order modulations. Results will be presented showing six-port and five-port, monolithically integrated coherent receivers. Six-port receivers are based in 90° hybrids with analog I/Q recovery, while five-port receivers are based in 120° couplers with digital I/Q regeneration, which can offer superior hardware compensation capabilities.