Adaptive Logic Control Strategy Based on Dual-Channel Radio Frequency (RF) Micro-Energy Harvesting System

To meet the power supply requirements of passive Internet of Things (IoT) sensor nodes, a dual-band radio frequency energy harvesting (RF-EH) system is proposed to enhance the efficiency of environmental energy capture. However, the conventional systems often suffer from energy loss due to variations in input power levels. This paper presents a dual-band (950 MHz/2.48 GHz) RF-EH system implemented using 180 nm standard CMOS process, with proposing a novel adaptive logic control strategy and the corresponding functional circuit that enables optimal selection of the energy harvesting path under different energy density conditions. The logic control circuit, composed of comparators, inverters, and transmission gates, can adaptively switch to the higher-power harvesting channel under the condition of output voltage <1 V (low energy density in antenna), while enables dual-band simultaneous energy harvesting with output voltage ≥1 V (high energy density). The circuit simulation results demonstrate that when the input RF signal power are −12.5 dBm (in 2.48 GHz band channel) and − 20 dBm (in 950 MHz band channel), the logic control circuit can achieve accurately the channel switching of the input high/low-power band, resulting in a stable output voltage of 1.332 V. When the whole system operates in dual-band synchronous energy harvesting mode, it can realize a maximum power conversion efficiency (PCE) of 78% and a wider dynamic input power range of 16 dB. This design effectively mitigates energy loss across multiple frequency bands and significantly improves the stability and efficiency of power supply for passive IoT nodes.