Photonic-assisted multi-format dual-band microwave signal generator without background noise.

Abstract

We report a photonic approach to generate background-free multi-format dual-band microwave signals based on a single modulator, which is suitable for high-precision and fast detection of radars in complex electromagnetic environments. By applying different radio-frequency signals and electrical coding signals to the polarization-division multiplexing Mach-Zehnder modulator (PDM-MZM), the generation of dual-band dual-chirp signals or dual-band phase-coded pulse signals centered at 10 and 15.5 GHz is experimentally demonstrated. Furthermore, by choosing an appropriate fiber length, we verified that the generated dual-band dual-chirp signals are not affected by chromatic-dispersion induced-power fading (CDIP); meanwhile, by autocorrelation calculations, we got high pulse compression ratios (PCRs) of 13 of the generated dual-band phase-encoded signals, showing that the generated phase-encoded signals can be emitted directly without extra pulse truncation operation. The proposed system features a compact structure, reconfigurability and polarization independence, which is promising for multi-functional dual-band radar systems.