Design of a novel TH-UWB signal generator based on 0.18-μm CMOS process

A novel time-hopping ultra wideband (TH-UWB) signal generator is designed for TH-UWB communications. The generator consists of a 4-GHz oscillator and a switch with CMOS transmission gates. Through controlling the low frequency signals with time-hopping pulse position modulation (TH-PPM), the circuit outputs TH-UWB signals with wavelets. Implemented in 0.18-mum CMOS technology, the generator provides the amplitude of 65 mV at 50 Omega load from a 1.8-V supply, and can directly drive an antenna by a transmission line. Meanwhile, the output impedance is matched to 50 Omega. The simulation results indicate that the performance of the generator is good and meets the standard of IEEE 802.15.3a.