高效率集成化CMOS能量获取关键技术研究

This project will mainly study the key design technologies in the RF and piezoelectricity energy harvester system for the sensor nodes and micro-electronic devices in Internet of Things. Firstly, the high-level models of RF antenna and piezoelectric sensor based Verilog-AMS are researched, and the high-precision analytical models for subsequent design simulation could be obtained. The traditional rectifier has the shortcoming of high start-up voltage, low conversion efficiency and large power consumption, which makes it not suitable to be used in the energy harvester system. This project will explore the near-zero start-up technology, the active negative voltage conversion with synchronized pulse control, and threshold-voltage compensation technology for the rectifier in the RF and piezoelectric energy harvester system. Based on 65nm CMOS process, we will combine the subthreshold character of the nano devices and the substrate driven or the pseudo-floating-gate technology. The ultra-low-power module circuits, such as reference circuits, operation amplifiers and comparators, will be researched to reduce the power consumption of the energy harvester system in this project. Finally, in order to expand the applications of the dual-mode energy harvester system, the low-power and non-invert bulk-boost DC-DC converter design based the average-current control mode is further researched in this project.

本项目主要研究适用于物联网中传感器节点以及微型电子设备的射频和压电双能量源的能量获取系统设计中关键技术。首先针对两种不同能量源的收集器，进行射频天线和压电传感器的高层次的建模研究，获得可用于后续设计仿真的高精度解析模型。针对传统整流电路启动电压高，转换效率低和自身功耗大的问题，深入开展射频和压电能量收集整流器设计中的近零启动、同步脉冲控制的有源负电压转换和阈值电压补偿等技术降低整流器的启动电压。基于65nm的CMOS工艺，充分利用器件的亚阈值特性，并结合衬底驱动和准浮栅等技术，开展超低低功耗的基准源电路、运算放大器、比较器等模拟单元电路的设计研究。最后，为了扩大双模能量获取系统的应用范围，本项目还将对基于平均电流模控制的同相低功耗升降压型DC-DC电压转换电路进行进一步研究。

本项目开展了射频能量和压电能量获取关键技术的研究，完成预期目标。研究人员设计了一个射频能量和压电能量混合获取系统，实现了通过射频整流器和压电整流器对射频能量和压电能量进行获取以及采用DC-DC转换器对获取的能量进行功率管理。针对射频能量，研究人员设计了阈值自补偿射频整流器，拓宽了射频能量获取的范围，提升了射频能量获取的效率。针对压电能量，研究人员设计了自供电有源迪克森整流器，以此得到较高的输出电压；此外，研究人员还利用有源二极管代替传统的肖特基二极管构成的有源全桥整流器，此外在整流器中加入了失调校准技术和功率提升技术（PSSHI）提高了压电能量获取的效率。研究人员还设计了低压启动低输出纹波boost转换器和双模式低功耗boost转换器对获取的压电能量和射频能量进行功率管理。低压启动低输出纹波boost转换器利用倍压技术使得boost转换器可以在低压下正常工作，利用自适应导通时间控制技术降低了输出电压纹波。双模式低功耗boost转换器通过双模式切换提升了转换器的效率。此外，研究人员还设计了低功耗的基准电压源，通过曲率补偿技术提升了基准的精度，利用时钟降幅电路消除时钟馈通和电荷注入对基准电压源的影响。