Dielectric-Loaded Conformal Microstrip Antennas for Versatile In-Body Applications

D. Nikolayev (1) , W. Joseph (1) , A. Skrivervik (2) , M. Zhadobov (3) , L. Martens (1) , R. Sauleau (3)

1 UGENT - Universiteit Gent = Ghent University
2 EPFL - Ecole Polytechnique Fédérale de Lausanne
3 IETR - Institut d'Électronique et des Technologies du numéRique

Wireless implantable bioelectronics and accurate in vivo characterization of path loss require efficient and robust in-body antennas. Loading electric antennas with the effective permittivities higher than that of surrounding tissues are a promising solution. In this letter, proof-of-concept conformal microstrip antennas are proposed. The antennas are optimized for a standard impedance of 50 \Omega and operate in all high-water-content tissues. Integral ground plane shields the antenna from inner circuitry. The radiation efficiencies are 0.4%, 2.2%, and 1.2% for the (434, 868, and 1400) MHz designs, respectively, when computed in a \varnothing100 mm spherical phantom with muscle-equivalent properties. The efficiencies are compared to the fundamental limitations and closely approach them. Specific absorption rates are evaluated, and the corresponding maximum input power levels are established. Prototypes are fabricated and characterized to validate the design.

Keywords: microstrip antenna; ingestible; Biomedical telemetry; capsule antenna; conformal antenna; implantable; in-body; robustness

Domains: Engineering Sciences [physics]

D. Nikolayev, W. Joseph, A. Skrivervik, M. Zhadobov, L. Martens, et al.. Dielectric-Loaded Conformal Microstrip Antennas for Versatile In-Body Applications. IEEE Antennas and Wireless Propagation Letters, 2019, 18 (12), pp.2686-2690. ⟨10.1109/LAWP.2019.2948814⟩. ⟨hal-02442755⟩