Affiliations: Graduate School of Information Science and Technology, Hokkaido University, Hokkaido, Japan
Correspondence:
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Corresponding author: Takuya Mori, Graduate School of Information Science and Technology, Hokkaido University, Hokkaido 060-0814, Japan. E-mail:tmori@em-si.eng.hokudai.ac.jp
Abstract: This paper presents optimal shape design of planar array
antennas for microwave energy harvesters. The topology optimization of the
C4-symmetric array antenna is conducted to maximize their isotropic gain
and minimize the return losses in a frequency band ranging from 1.5 to 3.5
GHz. Then, we design the rectifier by varying the circuit parameter based on
measurement results to realize the impedance matching between the optimized
antenna and rectifier. It is shown by experiment that the harvester composed
of the optimized array antenna and rectifier has higher receiving voltage in
comparison with the single one. Moreover, the resultant harvester is found
to start operating when the arrival electric field is greater than 0.1 V/m.
Keywords: Microwave energy harvester, wideband antenna, topology optimization, array antenna
