A low-power silicon-on-sapphire tunable ultra-wideband transmitter

A low-power tunable transmitter for ultra-wide band (UWB) radio was designed and fabricated. The design is based on a ring oscillator VCO, to produce short pulses. Both the pulse duration and frequency is controllable by two voltage biases. The transmitter can be used in both pulse-amplitude modulation (PAM) and pulse-position modulation (PPM). The circuit was fabricated on a 0.5mum silicon-on-sapphire CMOS process, and has been experimentally characterized with a transmitter and receiver module. The UWB transmitter produces monocycle pulses of 800 ps duration. The power consumption is 75muW when the pulse frequency is 3 MHz. The core pulse generator occupies 0.0091mm² of silicon area.