A microchip integrated temperature sensor with RF communication channel and on-chip antenna

摘要

A wireless CMOS temperature sensor chip performing an embedded RF antenna is presented. The RF carrier is produced by a three-stage ring oscillator that also acts as sensing element exploiting a linear dependence of oscillation frequency on temperature. The antenna is a square loop fabricated using the top metal layer provided by the 0.35 μm CMOS technology. Oscillation frequency shifts due to bias voltage fluctuations are circumvented by using a mathematical technique. The microchip provides an RF power level of -45 dBm at a distance of 1 m. The average power consumption is about 50 μW.