Multi-Band Software-Defined Coherent Radar Based on a Single Photonic Transceiver

In this paper, a photonics-based architecture of a multi-band coherent radar system is proposed and validated. The precision and flexibility of photonic technologies are exploited for generating and detecting simultaneously multiple radar signals in an extremely wide frequency range. Moreover, the fully digital approach enables the software-defined radio paradigm, allowing the flexible use of several advanced radar techniques such as waveform diversity or frequency hopping. The proposed architecture is therefore promising for future radar systems that need to adapt to different scenarios for improved situation awareness. The proposed system exploits a single laser unit for the multiband transmitter and receiver sections, reducing the architectural complexity with potential benefits on system dimensions, cost, and reliability. This paper details the principle of operation of the proposed multi-band coherent radar system, and describes the implementation of a proof-of-concept dual-band transceiver operating in the X- and S-bands simultaneously and independently. The results from the characterization of the transceiver are presented. The system validation through the coherent detection of moving targets confirms the suitability of the proposed solution, laying the basis for a new paradigm of radar systems.