An 868MHZ passive temperature sensing transponder using a self-biasing UHF rectifier with -10.5dBm sensitivity in low-cost 0.35µm CMOS

An 868MHz passive temperature sensing transponder in low-cost 0.35µm CMOS technology is presented. The transponder uses a self-biasing UHF rectifier achieving -10.5dBm sensitivity. Measurements are shown of the fabricated demonstrator including the RF frontend, rectifier and voltage regulator, a bandgap voltage reference and temperature sensor as well as the analog-to-digital converter and digital baseband. The device implements a subset of the ISO/IEC 18000-6 protocol and can communicatewith standard EPC readers.