A 750 μW 3.5–4.5 GHz FM-UWB transmitter

This paper presents an ultra-low power frequency modulated ultra-wideband (FM-UWB) transmitter implemented in standard 130 nm CMOS technology. The transmitter operates in the range of 3.5–4.5 GHz with 4 GHz RF carrier frequency. The transmitter can accept input data rates up to 250 kbps. A relaxation oscillator is used to generate the subcarrier signal and a VCO for RF carrier generation. The center frequency of the VCO is periodically calibrated to avoid out of band operation. An integer-N phase-locked loop (PLL) is used for both subcarrier generation and RF VCO calibration, which needs only 500 ns to complete the calibration. A class-AB power amplifier is used to output the power under the FCC mask. The proposed FM-UWB transmitter consumes 750 μW from a 1.2 V supply.