Design and development of a radio frequency energy harvester for low-power sensors

Özdemir, Huriye
This thesis presents a systematic design and implementation of a rectenna. As a beginning, a receiving antenna is proposed. In the design of the receiving antenna, a fractal topology is utilized to widen the antenna bandwidth. Moreover, a rectifier circuit with a proposed dualband matching technique is realized to aggregate the DC power. Ultimately, the broadband fractal antenna and the proposed dual-band rectifier circuit have been assembled to realize the rectenna. In addition, a simple RF spectrum study and a field measurement are conducted to obtain a better understanding of the available electric field density in the Middle East Technical University–Northern Cyprus Campus. Finally, the energy harvesting capability of the proposed rectenna has been verified in both controlled environment (laboratory) and ambient. As a result of the laboratory measurements, the proposed rectenna yields the highest RF-toDC conversion efficiency of 51.9% when the total power density of the two tone signal is 11.1 µW/cm2 . As a result of the ambient measurements, the proposed rectenna features an openvoltage in the range of 195–417 mV in the ambient when the highest electric field densities are 4.137 V/m and 1.818 V/m from the standards of GSM-900 and 3G (UMTS), respectively


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This thesis presents analysis, design, implementation, and testing of electrostatically actuated MEMS microvalves. The microvalves are specifically designed for lab-on-a-chip applications to achieve leakage ratios below 0.1 at pressure levels in the order of 101 kPa. For this purpose, two different microvalves are presented in the study. In the proposed designs, electrostatic actuation scheme is utilized to operate the microvalves in normally open and normally closed modes. Characterization of normally open...
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Design and implementation of A MEMS based gravimetric detector for cytometry applications
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This thesis reports design and implementation of a MEMS based gravimetric resonator for cytometry applications. There are mainly two objectives of this thesis; to enable in-flow analysis and to perform closed loop operation that does not require any additional processing or equipment. A novel MEMS based resonator with in-flow capabilities is proposed for detection of agents inside micro channels. High resolution of mass detection inside micro channels is planned to be succeeded with lateral motion in the mi...
Citation Formats
H. Özdemir, “Design and development of a radio frequency energy harvester for low-power sensors,” M.S. - Master of Science, Middle East Technical University, 2019.