This work proposes a Ultra-wideband (UWB) 7th derivative Gaussian pulse generator. The generated pulse conforms to the UWB emitting mask for outdoor applications. The produced pulse possesses a measured peak-to-peak amplitude of 160mV and a width of 500 ps. The PSD of the pulse has a -10 dB bandwidth of 5 GHz from 3.8 GHz to 8.8 GHz and a maximum of -44 dBmlMHz at 6 GHz. The pulse generator consumes 4 pJ/pulse from a 1 V supply. To the knowledge of the authors, the energy consumption is the lowest reported to date. It has been fabricated using 45 nm SOI CMOS technology and occupies 0.36 mm 2 including bond pads.