Antenna-in-Package Design and Robust Test for the Link Between Wireless Ingestible Capsule and Smart Phone

Abstract

An antenna-in-package 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 the considerations of frequency tuning, size reduction, and polarization diversity. First, 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. The 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. In addition to the advantages stated above, the proposed antenna is not sensitive to different digestive organs. Reflection measurement is presented using a muscle-mimicking phantom. Radiation characteristics are presented using a simple human torso model filled with pork by measuring the received power in a system. Successful data transmission, between a transmitter using the proposed antenna and a receiver using a smart phone, is performed in a temperature monitoring system.