FPGA-BASED RECONFIGURABLE CHIRP GENERATOR FOR L-BAND UAV CP-SAR

摘要

In this paper, an FPGA-based Real-Time Reconfigurable Chirp Generator is developed for L-band Unmanned Aerial Vehicle (UAV) Circularly Polarized Synthetic Aperture Radar (CP-SAR). The paper first outlines a proposed Direct Digital Synthesis (DDS) based reconfigurable chirp generator architecture whereby the chirp signal properties such as the bandwidth, the pulse width, the pulse repetition frequency, and its initial phase are real-time reconfigurable. Then, the discussion is followed by the design and development work of a compact custom-designed FPGA-based SAR signal synthesizer hardware. For validation purpose of the implemented architecture in the built hardware prototype, the waveform generated by the hardware prototype is benchmarked against an industrial grade Arbitrary Waveform Generator (AWG), Keysight N8241A AWG. The benchmark results showed that the signal quality of the waveform generated by the developed chirp generator is comparable to the industrial grade instrument.