• A battery-free wireless temperature sensing chipset is implemented in 55 nm and 65 nm CMOS processes, enabling continuous monitoring in food production.
• A calibrated oscillator-based CMOS temperature sensor replaces ADC-based circuits, achieving high precision with ultra-low power consumption.
• The sensor chip harvests power from a remote reader via wireless power transfer, eliminating the need for batteries.
• Experimental results demonstrate a temperature measurement error of ±1.6 °C from 25 to 50 °C with battery-free readout.