A Low-Power Complementary Metal-Oxide-Semiconductor Receiver with Quadrature Bandpass Continuous-Time Delta–Sigma Analog-to-Digital Converter for IoT Applications

This paper presents a low-power CMOS receiver with a complex continuous-time delta–sigma ADC designed for IoT applications in the 2.4 GHz band. The architecture employs a quadrature bandpass continuous-time delta–sigma ADC optimized for Bluetooth Low Energy (BLE) standards, achieving an ENOB of 10.9 bits while consuming only 0.81 mW from a 1.0 V supply. The receiver demonstrates impressive performance metrics, including a sensitivity of −95 dBm at a 10⁻3-bit error rate, an image rejection ratio of 54.2 dBc, and a spurious-free dynamic range of 79.8 dBc. Operating at a 1.5 MHz intermediate frequency with a 2 MHz bandwidth, the ADC achieves superior energy efficiency with a figure of merit (FOMW) of 103.2 fJ/conv. Implemented in 28 nm CMOS technology, the complete receiver occupies 0.375 mm2 for the RF front-end and 0.145 mm2 for the ADC while consuming 4.08 mW total power, making it well suited for battery-powered IoT sensor nodes requiring both power efficiency and reliable wireless connectivity.