A novel approach to generate a chirp microwave waveform using temporal pulse shaping technique applicable in remote sensing application

Microwave photonics is a prominent field in which photonic technologies are used to empower and extend the functionalities of microwave system which is a very tough exercise to fulfil directly in microwave domain. A photonic technique to generate a high chirp rate arbitrary microwave waveform using dual-drive LiNbO₃ has been put forward and demonstrated experimentally in this paper. Nowadays in order to increase the Range-Doppler resolution of radar, the chirp microwave waveform is widely used. The Mach-Zehnder modulator (MZM) performs the intensity modulation techniques which can operate on the principle of electro-optic effect. In this paper, the authors used a very simple and straightforward method of producing chirped arbitrary millimetre waveform by change in phase at the two arms of dual-drive LiNbO3 MZM. The generated waveform has the 3 dB bandwidth of 12.6 GHz which exists in extremely high-frequency band applicable in high-frequency microwave radio relay, microwave remote sensing, radar range resolution and millimetre wave scanner. The proposed design is simpler, cost-effective and compact than the previously proposed model of chirped waveform generation using MZM and fibre Bragg grating.