We present a synchronization method and coherent ultra-wideband transceivers for a widely separated multiple-input multiple-output (MIMO) radar. Synchronization is essential for MIMO operation, but a spatially spread radar array is not a good structure for it. A wireless cooperative synchronization method is based on coherency of pulse signals and highly accurate delay estimation and they are implemented through a coherent pulse generator and a fine delay-based receiver. Distance measurements of a radar transceiver (TRX) show that the maximum mean error is 4 mm for the target in a range of 0.2 m-8.0 m. Synchronization measurements of two radar TRXs show that the maximum mean error of the asynchronous time difference is 11 ps for the target in a range of 0.25-8.0 m. 2-D images for multiple targets and fluctuational radar cross sections are achieved with the proposed synchronization method under MIMO operation.