Photonic Generation of Multiband V and Cross Chirps using a Dual-Drive Mach Zehnder Modulator.

Chirp waveforms are extensively utilized in conventional radar systems because of their inherent pulse compression capability. However, they are limited by a poor range-Doppler resolution. Adversely, V- or cross-chirps exhibit complementary signals at the same time instant enhancing range-Doppler resolution. We propose and demonstrate a compact and straightforward microwave-photonic technique to generate multiband V- and cross-chirps by optimizing the DC and RF bias of a dual-drive Mach-Zehnder modulator. A theoretical study is performed, modeled, and validated by experiments showing the generation of dual- and cross-chirps centered 3 GHz and 9 GHz with a bandwidth of 2 GHz showing a time-bandwidth product of 20,000.