An 8-Channels FPGA-Based Reconfigurable Chirp Generator for Multi-Band Full Polarimetric Airborne/Spaceborne CP-SAR

摘要

This paper outlines the development work of a new Field Programmable Gate Array (FPGA) based chirp generator from which the new chirp generator is capable of synthesizing 4 pairs of I & Q chirp signals. The paper first proposes a multi-channel Direct Digital Synthesis (DDS) based reconfigurable chirp generator architecture whereby the chirp signal properties for each channel are independently reconfigurable in real-time. In addition, a reconfigurable Timing and Control Unit (TCU) is embedded into the system to generate the important timing synchronization signals which are essential for SAR hardware system. The proposed chirp generator is implemented on a custom-designed FPGA-based hardware platform with 8 on-board independent channels of Digital-to-Analog Converter (DAC). In future, the system will be used in Josaphat Microwave Remote Sensing Laboratory (JMRSL) airborne and spaceborne dual-band (C/X) full polarimetric Circularly Polarized Synthetic Aperture Radar (CP-SAR) system.