Digital Pre-Distortion to Reduce Ringing in Ultrawideband Radar Systems

In this paper, we present the development of a digital pre-distortion (DPD) algorithm to reduce ringing and improve received system fidelity factor in ultrawideband (UWB) radar systems. The DPD algorithm uses Wiener filter compensation followed by an iterative feedback loop to decrease measured ringing. To test the effectiveness of this algorithm at reducing distortion, we arranged antennas in a boresight configuration along with amplifiers at the transmitting and receiving nodes. We applied DPD to pulses with 20-dB bandwidths of 4.3 GHz and 8.46 GHz, respectively. Among tested pulses, the DPD method reduced root mean squared (RMS) ringing up to 11.27 dB, lowered peak ringing below −20-dB, and improved system fidelity factor above 90%.