用于射频能量收集的低阈值CMOS整流电路设计

Design of Low Threshold CMOS Rectifier Circuit for RF Energy Harvesting

基于TSMC 180 nm工艺,设计了一款高效率低阈值整流电路。在传统差分输入交叉耦合整流电路的基础上,提出源极与衬底之间增加双PMOS对称辅助晶体管配合缓冲电容的改进结构,对整流晶体管进行阈值补偿。有效缓解了MOS管的衬底偏置效应,降低了整流电路的开启阈值电压,针对较低输入信号功率,提高了整流电路的功率转换效率(PCE)。同时将低阈值整流电路三级级联以提高输出电压。测试结果显示,在输入信号功率为-14 dBm@915 MHz时,三级级联低阈值整流电路实现了升压功能,能稳定输出1.2 V电压,峰值PCE约为71.32%。相较于传统结构,该低阈值整流电路更适合用于射频能量收集。

A high efficiency and low threshold rectifier circuit was designed based on TSMC 180 nm process.On the basis of the traditional differential input cross-coupled rectifier circuit,an improved struc-ture of adding dual PMOS symmetric auxiliary transistors and buffer capacitors between source and sub-strate was proposed to compensate the threshold of the rectifier transistor.The substrate bias effect of the MOSFET was effectively alleviated.The turn-on threshold voltage of the rectifier circuit was reduced,and the power conversion efficiency(PCE)of the rectifier circuit was improved for the lower input signal power.At the same time,the low threshold rectifier circuit was cascaded in three stages to improve the output voltage.The test results show that when the power of the input signal is-14 dBm@915 MHz,the three-stage cascade low threshold rectifier circuit can realize the voltage boost function,and can output a stable voltage of 1.2 V,and the PCE is about 71.32%.Compared with conventional structures,the low threshold rectifier circuit is more suitable for RF energy harvesting.