Reconfigurable FM-UWB transmitter

A 100 kbit/s frequency modulated ultra-wideband (FM-UWB) transmitter with digitally reconfigurable subcarrier modulation index (β sub ), radio-frequency bandwidth (B RF ) and carrier frequency band is presented and fabricated in 0.18 μm CMOS. A delta-sigma (ΔΣ) fractional-N phase-locked loop with an amplitude-controlled relaxation voltage-controlled oscillator (VCO) and digitally configurable 2-FSK modulation is designed for subcarrier generation, followed by a dual-path LC VCO, the centre frequency of which is set by a digitally configurable duty-cycled frequency-locked loop for nearly 600 MHz UWB signal generation.