CPW-Fed Conformal PIFA Design for Implantable IoMT Devices With Wideband Performance
Rajeev Kumar, Surinder Singh
Abstract
This article presents a proposal for a conformal, miniature microstrip antenna with wideband capability for use in implantable and ingestible devices on the Internet of Medical Things (IoMT) for biotelemetry applications. The antenna is designed to perform for medical implant communication system (MICS 402–405 MHz) band inside the human skin tissue. The wideband feature of the proposed design also supports performing well inside various tissues environments. The co-planar structure of the antenna widens its bandwidth; as a result, antenna resonance performance has become tissue independently. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${L}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${U}$ </tex-math></inline-formula> slots are used to increase the radiation element length of an antenna. The antenna has been made using a single metallic layer on Roger RT/Duriod 6010 substrate. Furthermore, the antenna performance is also investigated by conforming to the antenna design with a radius of 5 mm. The proposed antenna is fabricated and tested inside artificial human skin mimicking phantoms. The antenna prototype has a volume size of 79.4 mm3, and its performance has been analyzed based on the reflection coefficient, radiation pattern, and specific absorption rate (SAR) value. The proposed design offers 134 and 142 MHz of bandwidth for planar and conformal design, respectively, with a maximum realized gain of −32.95 and −33.77 dBi, respectively, in homogeneous tissue. Finally, the proposed antenna is compact, wideband, and complies with SAR safety standard limits of up to 2.54-mW power. The investigated facilitates closer results concerning the numerical model.