Multi-band reconfigurable microwave photonic transceiver towards high-performance integrated radar.

As an effective approach to overcome the electronic bottlenecks of conventional electrical radars, microwave photonic radars have demonstrated significant superiority in their perception and recognition capabilities. However, trade-offs exist among the reconfigurability, signal time-bandwidth product (TBWP), linearity, and phase coherence of current photonic radars, which ultimately weaken the overall performance. To address these challenges, a photonic transceiver based on electrically assisted synchronized lasers is proposed and demonstrated, which combines high resolution and multi-band reconfigurability. Optical coherent heterodyne linear frequency-modulated (LFM) radar signal generation and photonic dechirping reception are implemented through the synchronized lasers at the transmitter and receiver, respectively. In a proof-of-concept experiment, reconfigurable LFM signals covering the L- to Ka-band with improved linearity and phase coherence are generated. Furthermore, the proposed photonic transceiver operates in the Ka-band with an ultra-large signal TBWP of 4 × 10, enabling high-resolution ranging and inverse synthetic aperture radar (ISAR) imaging. A range resolution of 1.92 cm and an imaging resolution of 1.92 cm × 1.89 cm are obtained, which require a receiver sampling rate of only 5 MSa/s. Featuring a simple structure, flexible reconfiguration, and integration compatibility, the demonstrated photonic transceiver opens new opportunities for next-generation miniaturized radar application scenarios.