Design of low power CMOS ultra-wideband 3.1–10.6 GHz pulse-based transmitters

The design of two low power CMOS ultra-wideband (UWB) pulse-based transmitters is reported. The goal is to propose simple, low power, and tunable topologies for full-band and sub-band UWB transmitters. The first transmitter utilizes a gated ring oscillator, an NMOS switch, and a passive pulse shaping filter to generate a 3.1-10.6 GHz full-band UWB signal. The second transmitter multiplies a carrier and a triangular signal to up-convert and generate a low side-band UWB signal for sub-band applications. We propose the use of two NMOS switches in series to perform this multiplication while consuming minimum power. Control voltages incorporated in both designs are used to adjust the shapes of the pulses to compensate for mismatch and process variations. Both the full-band and sub-band transmitters, fabricated in a 0.18 mum CMOS process, generate FCC compliant UWB signals with a supply voltage of 1.8 V and power consumptions of 237.4 and 254.9 muW, respectively.