A low-power, direct RF signal sampling receiver for short range wireless devices

A low-power sampling receiver dedicated to Industrial, Scientific and Medical (ISM) frequency bands applications is described in this paper. The receiver is based on a 4 path passive mixer. The mixer sampling rate fixes the carrier frequency of the received signal. A simple RC low-pass filter at the mixer´s output determines the receiver bandwidth. The structure used allows implementing flexible high-Q band-pass filters at the radio frequency side. The receiver has improved linearity and is robust to strong out-of-band blockers and adjacent channel interferences. A wideband 15 dB gain LNA permits to achieve a noise figure less than 4 dB between 400 MHz and 1.5 GHz. An integrated circuit was designed in a 0.13μm CMOS process. The receiver was tested. The power consumption is less than 11 mW at 1.2V power supply. The RF sensitivity is -102 dBm.