In this chapter, we discuss the advantages of exploiting photonic techniques in radar networks. More in detail, we first review the specific requirements of radar networks, focusing in particular on the coherence requested to the radar signals at the different network nodes. Then, we discuss the potentials of using photonics for distributing synchronization signals through optical fibers in distributed radar networks. Finally, we concentrate on the most performing radar network architecture, namely the centralized radar network, to report very recent experimental results enabled by photonics, and analyze the potential of a multi-input-multi-output (MIMO) processing approach in a radar network with widely separated antennas.