Digital Pre-Distortion to Reduce Ringing in a Pulse Sharpening Non-Linear Transmission Line

In this paper, we present the development of a digital pre-distortion (DPD) algorithm to reduce ringing in a UWB transmitter with a non-linear transmission line. Notably, this DPD is applied to a lower frequency bandwidth input pulse, translated to a much larger bandwidth output pulse where the ringing is reduced at the output pulse. A software-defined transmitter using an arbitrary waveform generator with 2.5 GHz of bandwidth implements the developed DPD algorithm. The non-linear transmission line sharpens the pulse to extend its bandwidth to 8 GHz. The DPD algorithm is developed using a look-up table of pulses characterized from the pulse sharpening system. The DPD algorithm reduces measured peak ringing in the output of the non-linear transmission line from −15.24 dB to −20.18 dB and RMS ringing from −26.4 dB to −30.5 dB.