Fractal inspired miniaturized wideband ingestible antenna for wireless capsule endoscopy

摘要

In this paper, a conformal wideband fractal implemented miniaturized antenna is presented for endoscopy capsule application over the 2450 MHz Industrial, Scientific and Medical (ISM) band. The thickness of the antenna is only 0.1 mm, which can be wrapped outside the capsule's wall. By implementing Minkowski fractal geometry in the patch, the proposed antenna obtains significant size reduction. A cubical shape muscle phantom is considered for initial design with parametric studies. To realize a more practical scenario, effect of the internal electronic components inside the capsule is discussed in detail, and also the variation of antenna's characteristics with respect to movement of capsule inside the gastro-intestinal (GI) tract has also been outlined. Further to study the bio-compatibility, specific absorption rate (SAR) of the proposed antenna is evaluated in different organs. The performance of the proposed antenna is experimentally validated by using a human phantom liquid mimicking the muscle tissue. From experimentation, it can be concluded that the antenna offers more than 30.6% fractional bandwidth in homogeneous tissue. Theoretically, the whole antenna assembly is electrically modeled and corresponding link budget calculation is accomplished. Link margin coming out from this study indicates the suitability of the proposed antenna in bio-medical applications. (C) 2020 Elsevier GmbH. All rights reserved.