Generation of a high chirp rate microwave signal by using external optical modulation technique for RADAR application: theory and experiment

In this work, the attainment of a high chirp rate random microwave waveform by using two port Lithium Niobate Mach Zehnder Modulator is reported and also experimentally verified. Numerous techniques are in trend to produce the chirp microwave signals where temporal pulse shaping is the most commonly used technique. Range-Doppler resolution of a radar system can be improved using the chirp microwave waveform by improving the chirp rate, time bandwidth product, and central frequency. In this paper, the author reported and successfully experimentally verified the dependency of chirp bandwidth and chirp rate on Laser Frequency and RF signal generator. We used a feasible and straight forward method of producing chirped arbitrary microwaves by using the external optical modulator. At the end of the paper, authors are able to compute the chirp rate, 3 dB bandwidth, OSSR, RFSSR value, and central frequency. It is shown that the experimentally obtained results match with the simulation data within the experimental limits.