A direct RF signal sampling integrated receiver for IoT applications

A low power Software-Defined radio receiver operating between 400 MHz and 1.5 GHz is presented in this paper. The receiver is based on differential switched 4-path passive mixer architecture. The sampling frequency fixes the carrier frequency of the received signal and a simple RC time constant determines the receiver bandwidth. The mixer structure permits to implement flexible high-Q band-pass filters at the RF side. This receiver has improved linearity and is robust to strong out-of-band blockers and adjacent channel interferences. A wide-band 15 dB gain LNA permits to achieve a noise figure less than 4 dB between 400 MHz and 1.5 GHz. The measured sensitivity is -83 dBm with an overall gain of 55 dB over the chain. The IIP3 of the receiver is -22.7 dBm and the power consumption is 45.7 mW under a 1.2V power supply voltage. The IC receiver has been designed in a 130nm CMOS process. The receiver is suitable for Internet of Things (IoT) applications.