• Journal of Biomedical Engineering Research
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• v.29 no.3
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• pp.187-190
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• 2008

This paper presents two dimensional receiving coils to provide hundreds of milli-watt power via inductive link to in vivo robotic capsules, whose orientation are practically undetermined. The wireless power transmission system consists of a transmitter powered by class E power amplifier, and a receiver with three dimensional antenna, rectifier, and voltage regulator. As the 2D lateral antenna construction is more critical for the receiving antenna, two types of 2D antennas are introduced and evaluated by theoretic and experimental analyses. Experimental results verifies that the cross-type construction show better directional performance for receiving power than the cylindrical one for the 2D antenna. The former could deliver the power homogeneously regardless of its orientation, with less than 20 % of variation from the possible maximum power.