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Circularly polarized implantable antenna characterization for retinal prosthesis systems

Kaka, AO and Toycan, M and Walker, SD (2018) 'Circularly polarized implantable antenna characterization for retinal prosthesis systems.' Turkish Journal of Electrical Engineering and Computer Sciences, 26 (3). 1180 - 1189. ISSN 1300-0632

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Abstract

We describe a miniaturized antenna design for retinal prosthesis applications that enhances data transfer between the implant and external camera. The circularly polarized and conformal 2.4–2.48 GHz microstrip patch antenna was simulated inside the vitreous humor and is intended for biomedical applications. Modified Hilbert and serpentine geometries were used for the proposed implant antenna design. Capacitive radiator loading offered miniaturized dimensions of 5.8 × 6.5 × 2 mm³ (width × height × thickness mm³). A truncated design enhanced the intrinsic circular polarization characteristics to >3 dB axial ratio. Polydimethylsiloxane substrate and superstrate materials were used to achieve an S11 value below –15 dB across the frequency range with biocompatible characteristics. The simulated peak gains for left-hand circular polarization and right-hand circular polarization at 2.45 GHz were –50 dBi and –60 dBi, respectively. These relatively small values were due to the high conductivity of the vitreous humor (s = 1.53 S/m), which imposed significant losses. Overall, the proposed antenna had an omnidirectional radiation pattern and +8.45 dBm input to meet the specific absorption rate regulation limit.

Item Type: Article
Uncontrolled Keywords: Implant antenna, miniaturized, circular polarization, retinal prosthesis systems
Subjects: Q Science > QA Mathematics > QA75 Electronic computers. Computer science
Divisions: Faculty of Science and Health > Computer Science and Electronic Engineering, School of
Depositing User: Elements
Date Deposited: 22 Jun 2018 14:53
Last Modified: 22 Jun 2018 14:53
URI: http://repository.essex.ac.uk/id/eprint/22309

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