A low power 2.4 GHz superheterodyne receiver architecture with external LO for wirelessly powered backscatter tags and sensors

We present a low power superheterodyne receiver architecture for wirelessly powered backscatter tags and sensors. This receiver architecture eliminates the power hungry local oscillator (LO) from the receiver by leveraging an external continuous wave (CW) carrier as both power source and LO source. The superheterodyne intermediate frequency (IF) is obtained from the output of a custom designed passive two-port mixer which simultaneously serves as an energy harvester. We have validated the proposed architecture at 2.4 GHz in benchtop proof-of-concept testing by successfully receiving and decoding Bluetooth Low Energy (BLE) advertising packets, which use GFSK modulation at 1 Mbps.