Pulse generator design for UWB IR communication systems

This paper presents a low power impulse generator design for ultra-wideband (UWB) impulse radio (IR) applications. Simple digital delay elements and a NAND gate are used to generate short duration pulses. A varactor controls the pulse width of the generated signal. The low-end of the spectrum of the generated pulse is attenuated using an integrated high-pass filter while the high-end of the spectrum is extended using a peaking inductor. This makes efficient use of the FCC spectral mask. The designed pulse generator in 0.18 μm TSMC CMOS technology consumes 0.4 mW at 100 MHz pulse repetition rate, and the spectral efficiency is more than 55%. The proposed IR generator topology gives a spectral efficiency improvement of more than 14% relative to the topology without the peaking inductor.