Impact of Tissue Electromagnetic Properties on Radiation Performance of In-Body Antennas

Abstract : In-body antennas couple strongly to surrounding biological tissues, thus, resulting in radiation efficiencies well below 1%. Here, we quantify how the permittivity and conductivity, each individually, affect the radiation efficiency of miniature implantable and ingestible antennas. We use a generic pill-sized capsule antenna and a spherical homogeneous phantom with its electromagnetic properties covering the complete range of body tissues. In addition to the phantom surrounded by air, we study the case with a reduced phantom-background contrast (nonresonant case) that allows for decoupling of the obtained results from the phantom shape. The results demonstrate that, for a realistic capsule antenna, the effect of dielectric loading by tissue can partially compensate for the tissue losses. For instance, the gain of the antenna operating in the muscle-equivalent medium is about two times (3 dBi) higher than in the fat-equivalent one, even though the conductivity of muscle is one order of magnitude higher than the one of fat. The results suggest that, in the majority of cases, in-body devices should be designed for and be placed within higher-permittivity tissues with low to moderate losses.
Document type :
Journal articles
Complete list of metadatas

https://hal-univ-rennes1.archives-ouvertes.fr/hal-01861301
Contributor : Laurent Jonchère <>
Submitted on : Friday, August 24, 2018 - 11:54:16 AM
Last modification on : Friday, November 16, 2018 - 1:29:49 AM

Links full text

Identifiers

Citation

Denys Nikolayev, Maxim Zhadobov, Ronan Sauleau. Impact of Tissue Electromagnetic Properties on Radiation Performance of In-Body Antennas. IEEE Antennas and Wireless Propagation Letters, Institute of Electrical and Electronics Engineers, 2018, 17 (8), pp.1440-1444. ⟨10.1109/LAWP.2018.2848943⟩. ⟨hal-01861301⟩

Share

Metrics

Record views

529