Antenna Design with Polarization Diversity for Wireless Ingestible Capsule

An antenna-in-package design is proposed for a wireless ingestible capsule operated at ISM (2.4-2.48 GHz) band, and also experimentally tested in a system level. The proposed antenna is designed for data transmission between the ingestible capsule and a smart phone using Bluetooth. A modified planar inverted-F structure is proposed for the antenna design, whose end section is bent to be vertical with respect to the substrate, mainly for considerations of frequency tuning, size reduction and polarization diversity. Firstly, a one-layer cube muscle phantom model is used for initial design and optimization. Then, a comprehensive evaluation method, with considerations of the polarization mismatch loss, is proposed to analyze the radiation performance using a CST human body model. Evaluated results indicate that, the proposed design can ensure enough margins for the link budget, despite the relative position between the capsule and the smart phone.