Design and SAR analysis of DGS based deformed microstrip antenna for ON/OFF body smart wearable IoT applications

Abstract This article presents a defected ground structure (DGS)-based deformed microstrip wearable antenna for ON/OFF body smart wearable Internet of Things (IoT) applications.. The antenna design has certain features such as lightweight, cost-effectiveness, low profile, and flexibility. Fabricated using a Rogers RT/Duroid 5880 substrate with a thickness of 0.508 mm, the proposed antenna includes a deformed rectangular patch and DGS to enhance impedance matching and radiation performance at 2.45 GHz. The results show a low reflection coefficient of approximately −36 dB and a peak gain of 5.61 dBi at 2.45 GHz in a free-space environment without bending. Additionally, the specific absorption rate (SAR) is measured to be 0.249 W kg −1 for 1 g of tissue and 0.137 W kg −1 for 10 g of tissue when the antenna is placed 0.32 λ 0 away from the body. The study also indicates that SAR values decrease as the distance between the antenna and the body increases. The antenna prototype has been fabricated and experimentally tested under various ON/OFF body conditions and bending scenarios. The measured results closely align with the simulated data, confirming the antenna suitability for ON/OFF body IoT applications. Noteworthy features of the proposed wearable antenna include its conformability and suitability for body-worn applications, making it an excellent candidate for ON/OFF body smart wearable IoT devices.