  Citation: Matthaiou, M.; Koulouridis, S.; Kotsopoulos, S. A Novel Dual-Band Implantable Antenna for Pancreas Telemetry Sensor Applications. Telecom 2022, 3, 1–16. https://doi.org/10.3390/ telecom3010001 Academic Editor: Sotirios K. Goudos Received: 21 November 2021 Accepted: 10 December 2021 Published: 1 January 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Article A Novel Dual-Band Implantable Antenna for Pancreas Telemetry Sensor Applications Maria Matthaiou * , Stavros Koulouridis * and Stavros Kotsopoulos Electrical and Computer Engineering Department, University of Patras, 26504 Patras, Greece; kotsop@ece.upatras.gr * Correspondence: ece8407@upnet.gr (M.M.); stavros.koulouridis@upatras.gr (S.K.) Abstract: In this study, a novel implantable dual-band planar inverted F-antenna (PIFA) is proposed and designed for wireless biotelemetry. The developed antenna is intended to operate on the surface of the pancreas within the Medical Device Radiocommunications Service (MedRadio 401–406 MHz) and the industrial scientific and medical band (ISM, 2.4–2.5 GHz). The design analysis was carried out in two steps, initially inside a canonical model representing the pancreas, based on a finite element method (FEM) numerical solver. The proposed antenna was further simulated inside the human body taking into account the corresponding dimensions of the tissues and the electrical properties at the frequencies of interest using a finite-difference time-domain (FDTD) numerical solver. Resonance, radiation performance, electrical field attenuation, total radiated power, and specific absorption rate (SAR), which determines the safety of the patient and the maximum permissible input power and other electromagnetic parameters, are presented and evaluated. Keywords: implantable antenna; PIFA; SAR; biotelemetry 1. Introduction In recent years, significant research has been made in wireless body area networks and their applications in the field of telemedicine. Specifically, implantable medical de- vices are widely used for the transmission of vital data. Their development creates the prospects for a better life quality of patients, especially those who suffer from chronic diseases [1]. For example, continuous non-invasive glucose monitoring can help patients suffering from diabetes, a very common, life-threatening disease. To carry out such an application, the antenna must be carefully designed, given that it provides a commu- nication link between the internal and the external sensor and that it is responsible for the radiation performance and the transmission of the electromagnetic waves. Such an application could be used in a sensor that will be informed about the glucose levels of the pancreas, then send the results to a sensor on the surface or outside the body, which will communicate with a doctor via the internet and regulate the levels of insulin to be taken by the patient. An implantable device has many requirements and a single operating band may not meet some of them since it needs to transmit data and be autonomous at the same time. Consequently, it is highly demanded to have multiband operation for other functions such as wireless power transfer and/or wake-up/sleep modes. Research on the dual band function of implantable antennas has been reported for example in [2–4]. This study is an extended version of our work reported in [5], where we presented the design of a novel implantable dual-band antenna and its performance simulated inside a cuboid pancreas model with dielectric properties of the pancreas. In this work, the proposed antenna’s function is further analyzed through simulations inside the pancreas of a male and a female human phantom, taking into account the impact of the human body on the signal propagation and the safety limits of the absorbed energy by surrounding tissues. Telecom 2022, 3, 1–16. https://doi.org/10.3390/telecom3010001 https://www.mdpi.com/journal/telecom