A highly miniaturised ultra-wideband antenna with a triple-band notch for wearable applications.

Abstract

In this paper, a compact Ultra-Wideband (UWB) antenna with a triple-band notch for wearable applications is designed and simulated for UWB applications with the operating frequency from 3.1 GHz to 10.6 GHz. The antenna can be used for UWB applications, while at the same time, is able to reject the narrowbands namely, Worldwide Interoperability for Microwave Access (WiMAX) (3.2 GHz to 3.6 GHz), C-band (3.7 GHz to 4.2 GHz) and Wireless Local Area Network (WLAN) (5.15 GHz to 5.35 GHz). Two slots are introduced on the radiating patch of the antenna to notch the three narrowbands, instead of three slots to notch each narrowband. The antenna is designed on a highly flexible polydimethylsiloxane (PDMS) substrate. The final outcomes indicate that the antenna can operate over the UWB frequency from 2.33 GHz to 11.30 GHz. The antenna is able to notch the WiMAX and C-band narrowbands with a frequency range from 3.08 GHz to 4.24 GHz and the WLAN band with a frequency range from 5.12 GHz to 5.40 GHz. The performance of the antenna in bending condition is also examined with the antenna bent over a varying diameter of vacuum cylinder starting from 50 mm, 80 mm and 100 mm. It is shown from the reflection coefficient of each diameter that the performance of the antenna is not affected by bending and thus, is particularly useful to be worn on body for wearable applications, other than its compact size of 19×14 mm2. The Specific Absorption Rate (SAR) results obtained shows that the antenna obeys the guidelines for 1 mW of input power.