Photonic Generation of Dual-Band Dual-Chirp Microwave Waveforms Using Cascaded Stimulated Brillouin Scattering

In this work, a dual-band dual-chirp microwave (DCMW) signal generation system is established based on the synergistic mechanism between cascaded stimulated Brillouin scattering (cascaded SBS) and an electro-optically synthesized frequency scanning laser source (FSLS). The system employs a single tunable laser as the optical carrier. A dual-loop optoelectronic oscillator (OEO) is utilized to selectively excite the − 1st- and − 2nd-order Stokes sidebands, respectively. Concurrently, an arbitrary waveform generator (AWG) drives a Mach–Zehnder modulator (MZM) to emulate the FSLS functionality, thereby eliminating the need for an additional RF local oscillator. Experimentally, two linear frequency modulated (LFM) microwave signals were successfully generated, centered at approximately 2.35 GHz and 6.35 GHz, each with a bandwidth of 7 GHz and a corresponding chirp rate of ± 5.3 GHz/µs. Preliminary analysis of the signal’s autocorrelation function and ambiguity function demonstrates that the dual-chirp waveform exhibits favorable pulse compression performance and low range–Doppler coupling, suggesting its potential for further exploration in future radar or anti-jamming communication applications.