Photonic Generation And Processing Of Broadband Linearly-chirped Signal

The rapid development of photonics technology has provided new techniques and approaches for the realization of wireless transceiver system with higher speed and broader bandwidth.Photonic-based arbitrary waveform generation and the transmitting and receiving of broadband signals are now the research focus.In this thesis,research is mainly focused on the photonic generation and processing of broadband linearly-chirped signal.We have proposed the method for the generation of broadband linearly-chirped signal based on spectral filtering and unbalanced dispersion,as well as an integrated architecture for generation and processing of broadband linearly-chirped signal.Main contents of the thesis are summarized as follows:(1)Five main methods for photonic-based arbitrary waveform generation are summarized and their advantages and disadvantages are compared.By tracking the latest research status of photonic-based transmitting and receiving of broadband signal,it is pointed out that an integrated architecture for generation and processing of broadband signal can be realized by combining signal generation and time-stretch technique.(2)A method for the generation of broadband linearly-chirped signal based on spectral filtering and unbalanced dispersion is proposed.The feasibility of the method is verified through theoretical analysis,numerical simulation and experiments.The tunability of the generated signal is studied,including generation of signal with large time-bandwidth product and generation of multi-band signal.In addition,the influence of higher-order dispersion on the generated broadband linearly-chirped signal is studied.(3)The content related to the integrated architecture of photonic generation and processing of broadband linearly-chirped signal is studied.Detailed processes for processing the received broadband linearly-chirped echoes with time-stretch technique are introduced.The single-target detection experiment has showed that the proposed method can be used to compress the frequency and bandwidth of echo signal.High-frequency signals can be processed with a lower sampling rate.The range resolution when using the X-band broadband linearly-chirped signal in double-target detection is verified through numerical simulation and experiments.Related processes in matched filtering processing of broadband linearly-chirped signal are also summarized.