A Compact Low-Profile P-Shaped Wearable Antenna for Medical Application

Abstract

This research article introduces a compact wearable antenna designed specifically for medical applications. The antenna underwent prototyping using a flexible Rogers Duroid RO3003™ material, featuring a small form factor measuring 35 × 32 × 0.5 mm3. In the initial phase of the design process, a basic P-shaped rectangular patch antenna was employed. However, during the first design iteration (Design 1), the antenna demonstrated a single resonance around 1.2 GHz, although it was not optimally matched at that frequency. To tackle this problem and achieve miniaturization involved the introduction of two rectangular patches positioned below the P-shaped patch known as Design 2. To further improve its performance, an inverted L-slot was incorporated. The frequency of operation for the antenna is 2.4 GHz, with a bandwidth measuring 25.2% ranging from (2.087–2.692) GHz. The measured radiation patterns demonstrate bidirectional properties in the E-plane and omnidirectional properties in the H-plane and maintain a high gain of 3.54 dBi and an efficiency of 91%. The SAR values are 0.018/0.013 Watt/kg on the chest. Similarly, the SAR values are 0.02/0.015 Watt/kg on the thigh, using 1/10 g of human tissue, which comply with the standards set by the FCC and the ICNIRP. Furthermore, the simulation and measurement under bending investigation and being close to the human body demonstrate excellent performance. Therefore, the suggested antenna holds significant potential as a compact solution for wearable medical applications.