Photonic approach for generating bandwidth-doubled and switchable multi-format chirp waveforms

A novel photonic approach for generating switchable multi-format chirp RF waveforms is proposed and experimentally demonstrated. The key component in the scheme is a dual-parallel Mach-Zehnder modulator (DPMZM). By properly setting the bias voltage on the DPMZM, different chirp RF waveforms with a doubled bandwidth, including the dual-, up-, and down-chirp waveforms, can be generated, when an unmodulated RF signal and a chirp RF signal are injected. The experiments are implemented to demonstrate the generation of switchable chirp waveforms with bandwidths of 2 and 0.8 GHz. The proposed scheme features its compact structure, easiness in switching control, as well as bandwidth doubling, which has potential applications in multifunctional radars.