Wireless sensors networks (WSN) have been gradually facilitating the pervasive connectivity of wireless sensor nodes. A greater number of wireless seneors have been used in different aspects of our life. However, limited device battery life restricts the applications of large-scale WSN. This paper presents a batteryless envelope detector with radio frequency energy harvesting (RFEH) for wireless sensor nodes, which enables simultaneous wireless information and power transfer (SWIPT). The envelope detector is designed for small modulation index AM signals with large amplitude variations. Therefore, the envelope detector is supposed to have wide input range while achieving a high conversion gain. We proposed an adaptive biasing technique in order to extend the input range of envelope detector. The input differential pair is adaptively biased through a feedback loop to overcome the variation of bias point when the amplitude of input signal changes. The cross coupled rectifier and DC-DC boost converter with maximum power point tracking (MPPT) are presented against power conversion efficiency (PCE) degradation of RF rectifier with the input power varying. The adaptive biased envelope detector is theoretically analyzed by square law MOSFET model. Designed with 0.18 m complementary-metal-oxide-semiconductor (CMOS) standard process, the power consumption of proposed envelope detector is 9 W. Simulated with a 915 MHz AM input signal with 2 Mbps data rate and 0.05 modulation index, the proposed envelope detector achieves 20.37 dB maxium conversion gain when the amplitude of input signal is 0.5 V, and the PCE of energy harvesting circuits achieves 55.2% when input power is –12.5 dBm.

中文翻译：

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具有宽输入范围的高转换增益包络检波器，用于同时无线信息和功率传输系统

无线传感器网络（WSN）已逐渐促进无线传感器节点的普遍连接。在我们生活的各个方面都使用了大量的无线监听器。但是，有限的设备电池寿命限制了大规模WSN的应用。本文提出了一种用于无线传感器节点的带有无线射频能量收集（RFEH）的无电池包络检测器，该检测器能够同时进行无线信息和功率传输（SWIPT）。包络检波器设计用于振幅变化较大的小调制指数AM信号。因此，假定包络检波器在获得高转换增益的同时具有宽的输入范围。为了扩展包络检波器的输入范围，我们提出了一种自适应偏置技术。输入差分对通过反馈环路进行自适应偏置，以克服输入信号幅度变化时偏置点的变化。提出了具有最大功率点跟踪（MPPT）的交叉耦合整流器和DC-DC升压转换器，以防止RF整流器在输入功率变化时功率转换效率（PCE）下降的情况。通过平方律MOSFET模型对自适应偏置包络检波器进行了理论分析。拟议的包络检波器采用0.18 m互补金属氧化物半导体（CMOS）标准工艺进行设计，功耗为9W。在915 MHz AM输入信号，2 Mbps数据速率和0.05调制系数的模拟下，拟议的包络检波器当输入信号的幅度为0.5 V时，可实现20.37 dB的最大转换增益，