Photonic generation of dual-mode multi-format chirp microwave signals

In this paper, we present a novel, to the best of our knowledge, photonic scheme for the generation of dual-mode multi-format chirp microwave signals, utilizing a dual-drive dual-parallel Mach-Zehnder modulator (DD-DPMZM). By inputting a single-chirp signal and controlling the input binary sequences, the proposed method can generate up-, down-, dual-, or triangular-chirp signals in both pulse and continuous-wave modes. Moreover, the duty cycle of the generated chirp signals in the pulse mode can be easily adjusted by manipulating the injected binary sequences. The compact structure of the proposed scheme eliminates the need for polarization control in signal switching and avoids the use of any optical filter. Experimental verification confirms the feasibility of our approach, while also pointing towards its promising applications in multi-functional radar systems.