This paper presents an ultra-wideband pulse generator based on a duty-cycled 2-ASK emitter able to generate OOK and BPSK modulated carriers. This emitter uses a differential architecture which has been designed in FD-SOI 28 nm CMOS technology with a supply voltage of 1.0 V. It presents a fast enough transient response to entirely cover the 3.1-10.6 GHz FCC band. Moreover, it can be quickly turnedon and turned-off which allow 3 ns pulses to be generated and also, low power impulse communications to be implemented. The emitter is built around a wideband Voltage Controlled Oscillator (VCO) which is able to generate at its outputs large oscillations from 1.0 GHz to 13.9 GHz. When the emitter is used as a 3 ns pulse generator centred on 7987 MHz, its energy consumption is 152.7 pJ/pulse, and the static power consumption is 3.83 μW. This leads to a mean power consumption of 5.36 µW (resp. 19.1 µW and 156 µW) for a pulse repetition frequency of 10 kHz (resp. 100 kHz and 1 MHz), which highlights the interest of impulse modulations for low power radio-frequency communications.