Analysis and design of chirped pulse generator for WBAN transmitter

Abstract

A new pulse generator based on chirp spread spectrum technique for impulse radio ultrawideband (IR-UWB) transmitter operating in the 3-5GHz band is described in this paper. It consists of a differential ring oscillator controlled by a ramp generator. ON/OFF switching operation is used in order to save power consumption. Simulated in a 0.18μm CMOS process, the results show a worse case phase noise of −105 dBc/ Hz at 10 MHz offset, a pulse duration of 20ns and a pulse repetition frequency (PRF) of 10MHz. The output spectrum fully complies with the FCC spectral mask with more than 22 dB of side lobe rejection. The circuit dissipates 1.7mW from 1.8V power supply and achieves an energy efficiency of 0.17 nJ/bit.