Arbitrary frequency multiplication reconfigurable radar with a lithium niobate repetition-rate-modulated frequency comb

Robust and high-resolution radars are desirable for emerging applications ranging from the Internet of Everything to autonomous driving. Photonic radars with frequency multiplication have attracted considerable interest for providing high frequency, large bandwidth, and immunity to electromagnetic interference. Nevertheless, their wideband reconfigurability has been restricted by limited and fixed multiplication factors, which hinders robust sensing. In this work, we overcome the constraint by implementing a repetition-rate-modulated frequency comb that enables arbitrary frequency multiplication. Key components, including a phase modulator with 0.74 V half-wave voltage and an intensity modulator with 110-GHz bandwidth fabricated on the thin-film lithium niobate (TFLN), enhance radar performance. The transmitter achieves a record-breaking cross-band operation bandwidth (5.95 to 95.2 GHz), corresponding to a tunable multiplication factor range of 1 to 16. The receiver supports optical dechirping across 0 to 110 GHz. System-level ranging demonstrations, using two distinct radar waveforms, achieve centimeter-level (2.6/3.5 cm) and real-time resolution. We offer a viable solution for next-generation photonic integrated radar using the TFLN platform.