合成孔徑雷達技術是重要的遙測工具，然而傳統合成孔徑雷達系統必須使用大功率輸出脈衝模組，造成輕型載具使用上的限制。調頻連續波雷達具有體積小、低廉的優點。結合合成孔徑雷達技術，可以開發體積小、輕量、經濟的高品質影像酬載。因此，FMCW-SAR系統可以應用在民用工程、地球觀測、遙測科學等領域。 本研究建構FMCW-SAR的數位電路部分，包含了：數位/類比轉換器、數位信號控制器、傳輸暫存器、電腦通訊協定…等功能的實現。在開發平台的選擇上，可程式邏輯晶片（FPGA）具有獨特優點如設計容易修改，功耗小、重量輕…等，因此選擇FPGA作為開發初期的工具。FMCW雷達的基頻類比訊號經過取樣數位化，藉著控制器傳輸訊號儲存在記憶體內，最後傳輸到電腦上得到原始資料(raw data)，以透過合成孔徑的演算法得到符合理論解析度的影像。 FMCW (Frequency Modulated Continuous Wave) radar systems are generally small-scale and relatively cheap to development and research. With Synthetic Aperture technique, the radar system leads to development of a small, lightweight, and cost-effective high resolution imaging sensor. Consequently, FMCW-SAR systems can apply in many fields such as civil engineering, Earth observation and remote sensing science. In this study, we focus on digital circuit design for signal processing. This includes analog/digital converter, digital signal controller, transmission buffer, PC communication protocol, etc. To utilize the field programmable gate array (FPGA) as a platform because FPGA has many advantages such as easy modification or light weight. The FPGA-based signal processing unit has functions of sampling and storing. We apply synthetic aperture processing to image by the FMCW system. The results show that the accuracy of position or size has meeting the specifications.
