Study of CMOS Rectifers for Wireless Energy Scavenging

• Main Author: Khalifa, Aiysha
• Format: Others
• Language: English
• Published: Linköpings universitet, Elektroniska komponenter 2010
• Subjects: Energy Scavenging; Rectifier
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-69683

In recent years, there has been recent increase in the deployment of wireless sensor networks. These sensors are typically powered by a battery which has limited life span. This problem can be overcomed by using energy scavenging or power harvesting which is the process of converting ambient energy from the environment into usable electrical energy. It can be used in applications such as remote patient monitoring, implantable sensors, machinery/equipment monitoring and so on. The thesis presents the RF scavenging system and mainly focuses on the study of the rectifier architectures which is one of the key components in the RF scavenging system. The thesis also provides the design challenges while implementing the different rectifier structures, which are PMOS bridge rectifier, CMOS differential rectifier and charge pump. The functionality of the rectifier structures are studied by simulation using RF signal of 900 MHz and implemented in 0.35μm and 65 nm technologies to compare the results. The simulation results shows that there is a tradeoff between high output DC voltage and high power efficiency. Maximum DC output voltage of 1 V is obtained from input amplitude level of 0.16 V using 7-stage charge pump rectifier. In the other hand maximum power efficiency of 23 % is obtained using CMOS differential rectifier.