An SiGe-chip-based 80 GHz FMCW-radar system with 25 GHz bandwidth for high resolution imaging

Existing SAR systems are often limited in resolution by their small bandwidth of below 10 GHz. In this contribution an ultra-wideband 80 GHz FMCW radar sensor for SAR imaging with 25.6 GHz bandwidth is presented. It is based on a custom low-power SiGe-MMIC including all high frequency components, using a nested PLL concept in combination with off-the-shelf PLL synthesizer ICs. In single direction radar measurments, a resolution of 8.09mm is shown. Additionally, results of SAR measurements with a point target show that a good spatial resolution of 12.0 mm × 8.1 mm (Tukey window, = 0.25, -6 dB width) is achieved. Furthermore, high resolution SAR images of a bike acquired with the sensor are presented.