Hosain Md Kamal, Kouzani Abbas Z, Tye Susannah, Kaynak Akif, Berk Michael
School of Engineering, Deakin University, Waurn Ponds, Geelong, VIC, 3216, Australia,
Australas Phys Eng Sci Med. 2015 Mar;38(1):157-72. doi: 10.1007/s13246-015-0328-7. Epub 2015 Jan 20.
A passive deep brain stimulation (DBS) device can be equipped with a rectenna, consisting of an antenna and a rectifier, to harvest energy from electromagnetic fields for its operation. This paper presents optimization of radio frequency rectifier circuits for wireless energy harvesting in a passive head-mountable DBS device. The aim is to achieve a compact size, high conversion efficiency, and high output voltage rectifier. Four different rectifiers based on the Delon doubler, Greinacher voltage tripler, Delon voltage quadrupler, and 2-stage charge pumped architectures are designed, simulated, fabricated, and evaluated. The design and simulation are conducted using Agilent Genesys at operating frequency of 915 MHz. A dielectric substrate of FR-4 with thickness of 1.6 mm, and surface mount devices (SMD) components are used to fabricate the designed rectifiers. The performance of the fabricated rectifiers is evaluated using a 915 MHz radio frequency (RF) energy source. The maximum measured conversion efficiency of the Delon doubler, Greinacher tripler, Delon quadrupler, and 2-stage charge pumped rectifiers are 78, 75, 73, and 76 % at -5 dBm input power and for load resistances of 5-15 kΩ. The conversion efficiency of the rectifiers decreases significantly with the increase in the input power level. The Delon doubler rectifier provides the highest efficiency at both -5 and 5 dBm input power levels, whereas the Delon quadrupler rectifier gives the lowest efficiency for the same inputs. By considering both efficiency and DC output voltage, the charge pump rectifier outperforms the other three rectifiers. Accordingly, the optimised 2-stage charge pumped rectifier is used together with an antenna to harvest energy in our DBS device.
一种无源深部脑刺激（DBS）设备可配备由天线和整流器组成的整流天线，以便从电磁场中获取能量来维持其运行。本文介绍了用于无源头戴式DBS设备中无线能量采集的射频整流器电路的优化。目标是实现尺寸紧凑、转换效率高且输出电压高的整流器。基于德隆倍压器、格雷纳赫电压三倍器、德隆电压四倍器和两级电荷泵架构设计、模拟、制造并评估了四种不同的整流器。设计和模拟使用安捷伦Genesys在915 MHz的工作频率下进行。使用厚度为1.6 mm的FR - 4介电基板和表面贴装器件（SMD）组件来制造所设计的整流器。使用915 MHz射频（RF）能量源评估所制造整流器的性能。在输入功率为 - 5 dBm且负载电阻为5 - 15 kΩ时，德隆倍压器、格雷纳赫三倍器、德隆四倍器和两级电荷泵整流器的最大测量转换效率分别为78%、75%、73%和76%。整流器的转换效率随着输入功率水平的增加而显著降低。德隆倍压器整流器在输入功率为 - 5 dBm和5 dBm时均提供最高效率，而对于相同输入，德隆四倍器整流器效率最低。综合考虑效率和直流输出电压，电荷泵整流器优于其他三种整流器。因此，优化后的两级电荷泵整流器与天线一起用于我们的DBS设备中以采集能量。
