SiGe-MMIC based D-Band radar for accurate FMCW multi-target vibration measurements

In this paper a wideband D-Band radar for high precision multi-target vibration measurements is presented. The system is based on a PLL stabilized SiGe MMIC with two VCOs for highly linear fractional-N FMCW sweep generation from 122 to 170 GHz and ≈1ms ramp duration. To demonstrate the capabilities of the FMCW radar, first measurement results are presented. Due to the ultra-wide bandwidth of 48 GHz (≈33%) and the resulting range resolution of 6.04mm (-6 dB width, Hanning window), target separation is even possible in very dense multi-target environments. In freespace measurements with a target in 1 meter distance to the antenna and a SNR of ≈50 dB a distance standard deviation of better than 10 μm is achieved. The combination of phase and peak-center algorithms allow vibration measurements even for fast and large amplitude oscillations. In addition range doppler plots are presented for advanced high precision movement analysis in multi-target environments.