Dual-band Conformal Capsule Antenna Design for Biotelemetry Applications

In this paper a compact conformal capsule antenna design based on the inverted-F antenna (IFA) is proposed for dual-band biotelemetry applications. The primary radiator of the suggested antenna is composed of a meander-line loaded spiral-type resonator which is used instead of the typical F-structure. To improve impedance matching, the antenna ground plane is modified by introducing a proper ring slot. The overall size of the compact antenna is only $14 \times 29.8 \times 0.125 \mathrm{~mm}^{3}$. According to the numerical results obtained using the CST microwave studio homogeneous model, the encapsulated conformal antenna operates at 402 MHz MICS and 2.45 GHz ISM bands with 18 and 90 MHz bandwidths, respectively.