This paper proposes a high-sensitivity, low-noise dual-band RF energy harvesting and managing system for wireless bio-potential acquisition. The proposed system consists of a dual-band RF energy harvester, a voltage monitor, and a power management unit (PMU). The proposed dual-band RF energy harvester adopts the hybrid threshold voltage self-compensation technology, which effectively reduces the equivalent threshold voltage of transistors and improves the power conversion efficiency (PCE). To match the input power and the load power with the minimum current consumption, a low-power voltage monitor is proposed in this paper. Moreover, the proposed PMU combines a voltage bootstrap circuit and a low-noise high-PSRR LDO to avoid the use of off-chip inductors and suppress output ripple. The proposed chip was implemented in a 0.18-μm deep n-well CMOS process, occupying a core area of 1.30 mm✕2.06 mm. The measured results show the dual-band RF energy harvester outputs a DC voltage of 1 V in two different frequency bands at the input power as low as −18.5 dBm. The PMU outputs stable DC voltages of 1 V and 1.8 V in working mode. In sleep mode, only the voltage monitor is working, and the average quiescent current is only 0.6 μA.

本文提出了一种用于无线生物电势采集的高灵敏度、低噪声双频射频能量收集和管理系统。建议的系统由双频射频能量收集器、电压监视器和电源管理单元 (PMU) 组成。提出的双频射频能量采集器采用混合阈值电压自补偿技术，有效降低晶体管等效阈值电压，提高功率转换效率（PCE）。为了以最小的电流消耗匹配输入功率和负载功率，本文提出了一种低功率电压监测器。此外，所提议的 PMU 结合了电压自举电路和低噪声高 PSRR LDO，以避免使用片外电感并抑制输出纹波。建议的芯片是在 0. 18-μm深n-well CMOS工艺，核心面积1.30 mm✕2.06 mm。测量结果显示，双频射频能量采集器在输入功率低至 -18.5 dBm 的情况下，在两个不同频段中输出 1 V 直流电压。PMU 在工作模式下输出稳定的 1 V 和 1.8 V 直流电压。在睡眠模式下，只有电压监视器在工作，平均静态电流仅为 0.6 μA。