A fiber-distributed bistatic ultra-wideband radar based on optical time division multiplexing

A fiber-distributed bistatic ultra-wideband (UWB) radar based on optical time division multiplexing (OTDM) is proposed and demonstrated. The proposed radar consists of a central office (CO) and two spatially separated transceivers. OTDM technology is implemented by inserting a certain length of optical fiber between the two radar transceivers, so the UWB pulses received by different transceivers can be identified by the time slots they are presented in. The UWB pulses emitted from different transceivers are designed to have opposite polarities, so it is easy to identify which transceiver the echo UWB pulse is emitted from. Therefore, the information of target in the radar coverage area can be extracted with single-channel cooperative signal processing in the CO. In addition, wavelength-reuse is applied in each transceiver to simplify the system and polarization division multiplexing is employed to avoid optical interference. An experiment is carried out, showing that 2-D localization with centimeter-level accuracy can be achieved.