Phase tracking multichannel link

Abstract

A phase tracking multichannel apparatus includes a plurality of optical transmitters, an optical multiplexer, a common optical link, and a user electronics. RF signals having different phases are received and are output on separate RF channels, each of which is coupled to an optical transmitter. RF-modulated optical output signals are then output to the optical multiplexer to produce a multiplexed output signal. The multiplexed signal is applied to a common optical link that at its output substantially maintains the phase separation of RF modulation components on optical carriers as received at its input. The optical output of the common optical link is then applied to an optical signal receiving system, such as an optical demultiplexer and a plurality of photodetectors. By multiplexing all of the optical signals onto the common optical fiber, all signals transmit the same path and, therefore, have the same time and phase delay. The phase tracking is preserved because all of the signals experience the same optical or expansive properties of the common optical fiber. A typical use would be to transmit multiple RF signals from an antenna array to a remote RF phase measuring receiver, such as a RF direction finding system.