Low power design for integrated energy harvesting systems
Al-Shebanee, Durgham; Heinen, Stefan (Thesis advisor); Negra, Renato (Thesis advisor)
Aachen (2016) [Book, Dissertation / PhD Thesis]
Page(s): 1 Online-Ressource (xxiv, 126 Seiten) : Illustrationen, Diagramme
The energy harvesting is defined as a process by which the energy provided from various sources is transformed to electrical power. This principle has recently attracted a considerable interest in the academic and the industrial fields. The aim of the thesis is to recondition the harvested energy in order to reach the requirements of the sensor circuits used in the energy harvesting applications. Furthermore, it is intended to present various CMOS circuit solutions for conditions of low power low-voltage available from the harvester. Thermal and RF energy harvesting methods are associated with such harvested power conditions and require different voltage conversion circuits, thus, fitting optimally with scope of the work. In this work, a highly sensitive CMOS RF energy harvesting system and low input voltage DC-DC CMOS boost converter for thermal energy harvesting have been presented. The presented RF energy harvesting system consist of differential input cross coupled rectifier and low power charge pump. The measurements results show that using the charge pump is helpful to maximize the DC output voltage for low RF input power with wide bandwidth. The calibrated system sensitivity to produce more than 1V for a capacitive load is −25dBm within a frequency range of 800MHz to 870MHz. On the other hand, the Low input voltage CMOS boost converter is proposed to be used for thermal energy harvesting. The boost converter consists of self start-up oscillator, inductor based boost and control circuit. The measurements results shows that the proposed converter design is optimum for thermal energy harvesting applications of low input voltage. The boost circuit can start up with source voltage of 12mV. Furthermore, when the inductor based boost circuit is activated, the output voltage is raised to be 2V to 2.9V for source voltage range of 30mV to 100mV with an average efficiency of 31%.