A 2.4 GHz Low Power Low-IF Receiver Employing OOK and FSK Dual-Mode Demodulator for IoT Applications

In this paper, a 2.4 GHz low-power low-IF receiver employing a dual-mode demodulator for on-off keying (OOK) and frequency-shift keying (FSK) signals is presented for Internet of Things (IoT) applications. The switched dual-mode demodulator can demodulate both OOK and FSK signals. The proposed receiver consists of a low-noise transconductance amplifier, single-balanced current-mode passive mixer, transimpedance amplifier, variable gain amplifier, and dual-mode demodulator. The proposed receiver was designed in a 65-nm CMOS process and mainly simulated at 2.4 GHz. The receiver achieves a noise figure of 9.9 dB, a maximum conversion gain of 74 dB, and an input-referred third-order intercept point of −26.3 dBm. The active die area of the designed receiver is 0.53 mm2, and it draws a bias current of 1.8 mA from a nominal supply voltage of 1 V.