Low-Complexity DC-Offset-Cancellation Mechanism for 1-Mbps FM-UWB Receiver

A frequency-modulated ultrawideband (FM-UWB) receiver (RX) is fabricated in 65-nm CMOS, to feature high energy efficiency, high robustness, and low complexity. Both the offset-insensitive RF front end and the offset-immune intermediate-frequency (IF) module are proposed for the DCoffset elimination of FM-UWB RXs. The active-balun embedded low-noise amplifier (LNA), symmetric-detuning bandpass filters (BPFs), single-ended envelope detectors (ENV-DETs), and self-biased IF amplifiers contribute to offset cancellation and distortion suppression and thus benefit high sensitivity and linearity. Digitally reconfigurable switched-capacitor arrays ensure design robustness. Experimental results show that the 3.75-4.25-GHz RX achieves a sensitivity of -81 dBm, a noise figure (NF) of4.0dB, and an energy efficiency of 1.8 nJ/bit, with an active area of 0.65 mm2 and a power dissipation of 1.8 mW from a 1-V supply at a data rate (DR) of 1.0 Mbps.