A 13.56/402 MHz autonomous wireless sensor node with −18.2 dBm sensitivity and temperature monitoring in 0.18 /im CMOS

A multi-band autonomous wireless sensor node (AWSN) with temperature monitoring is designed in a standard 0.18 μm CMOS technology. The AWSN comprises a high efficiency energy harvester, a power management module, a temperature-to-time converter (TTC) and a passive 402-MHz MICS band OOK transmitter for backscattering transmission. The AWSN demonstrates a sensitivity of -18.2 dBm at 13.56 MHz. The energy harvester achieves an RF-to-DC power conversion efficiency (PCE) of 11.5 %. From 0 to 100 °C, the temperature conversion and temperature accuracy of the TTC are 1.5 μs/°C and 0.21 °C, respectively. The active area of the AWSN is 0.72 mm2. It consumes 1.5 μW (RMS).