This thesis focuses on key challenges in the design of a radio-frequency front-end for microwave photonic radar systems and the experimental measurement of the micro-Doppler phenomenon. The first part presents a brief overview of the history and operating principles of radar systems based on Doppler shift. It includes the detection of small unmanned aerial vehicles using a frequency-modulated radar and a concise review of existing drone detection systems in the military sector. Additionally, it introduces photonic integrated circuit technology and describes the structure of a photonic integrated radar, accompanied by a practical demonstration of radio-frequency signal generation in the optical domain.
The second part proposes a design for the high-frequency front-end of a photonic radar system. The design includes the development of both the transmission and reception amplifier chains, detailing component selection and the assembly of individual elements. The description is supported by graphical representations of measurements carried out on specific components of the amplifier chains. This section also includes the design of a transmit–receive antenna, with a detailed explanation of the design and fabrication process. Finally, simulation results are compared with laboratory measurements to validate the performance of the developed system.
The final part describes the experimental procedure for measuring micro-Doppler responses of rotor blades from commercial drones using a 10 GHz Doppler radar. The radar system was assembled using equipment from the Radiation and Optics Laboratory, supplemented by previously developed and described components. The section outlines the complete experimental setup, including the construction of a drone motor support, motor speed control, rotor blade preparation, and laboratory deployment of the Doppler radar. The measurement procedure is presented in detail, with results illustrated through peak-to-peak voltage graphs and waterfall spectrograms. The findings are concluded with an analysis of results and a calculation of the theoretical detection range of the assembled radar system.
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