Novel phase error compensation algorithm for direct digital synthesizer chirp generator in synthetic aperture radar

Heein Yang, Yuta Izumi, Josaphat Tetuko Sri Sumantyo


This paper proposes a novel phase error compensation algorithm for the direct digital synthesizer (DDS) chirp generator of high-resolution synthetic aperture radar (SAR). The proposed compensation algorithm adopts the curve fitting method to calculate the error of transmission SAR signal called chirp. In addition, this paper proposes the polynomial modeling method during chirp generation stage to improve spectrum characteristics. The mathematical equations proposed in this paper indicate that the phase shift of chirp in time domain can be eliminated clearly. Simulation results show that the proposed compensation algorithm enhances the peak-to-side lobe ratio (PSLR) and the integrated side ratio (ISLR) up to -0.2068 dB and -0.1091 dB respectively. In addition, spur components have been reduced when compared to the spectrum output of conventional DDS output.


Synthetic Aperture Radar; Direct Digital Synthesizer; Linear Frequency Modulation; Chirp Signal; Phase Error Compensation

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