An Efficient and Compact Monopole Antenna Backed With Square Loop EBG Structure for Medical Wireless Body Area Network Applications

Abstract

AbstractIn this paper, a compact, low‐profile, and simple monopole antenna is presented that is operated at the frequency of 2.4 GHz in industrial scientific medical band. The monopole antenna is based on the simple rectangular microstrip patch with a rotated T‐shaped slot. Furthermore, a 2 × 2 electromagnetic band‐gap (EBG) array is used in this design to act as an isolator between the antenna and the human body, which additionally increases the performance of the proposed antenna. The final design has an overall size of only 0.9λg × 0.9λg × 0.034λg (60 × 60 × 2.3 mm3) where λg is the guided‐wavelength with respect to RO4003 substrate at the resonant frequency of 2.4 GHz. This can make the structure a good candidate for wireless body area network applications. A prototype of the designed EBG‐based antenna is fabricated over a widely available RO4003 substrate. The measurement results show a gain of 6.52 dBi, a front to back ratio of 12.12 dB, and a total efficiency of 79.87% around the resonant frequency. Furthermore, numerical studies are conducted to evaluate the specific absorption rate (SAR) of the proposed design, which shows by introducing the EBG structure, more than 96% reduction in SAR level is obtained. All simulations are carried out by CST microwave studio software.