Photonic Generation and Transmission of Dual-Band Dual-Chirp Microwave Waveforms at C-Band and X-Band With Elimination of Power Fading

We propose a photonic method to generate and transmit dual-band dual-chirp microwave waveforms based on a dual-polarization dual-parallel Mach-Zehnder modulator (DP-DPMZM). The key novelty of this work is the generation of dual-band dual-chirp waveforms with flexible central frequency relationship to meet the requirement of the dual-band radar system, and transmission of the generated waveforms with elimination of power fading. In the proposed method, dual-band dual-chirp microwave waveforms are generated by applying two different RF signals and a parabolic coding signal to the DP-DPMZM. By properly adjusting the DC biases of the x -DPMZM and y -DPMZM, dispersion-induced power fading effect in the transmission of the generated waveforms can be compensated. A proof-of-concept experiment is conducted to generate and transmit dual-band dual-chirp microwave signals at C-band and X-band (centered at 7 GHz and 10 GHz) with tunable bandwidth. The proposed system has a simple structure and good reconfigurability, which has great potential in applications such as dual-band radar systems.