Novel wearable eagle shape microstrip antenna array with mutual coupling reduction

Novel eagle shape microstrip wearable antennas (element and array) are presented. The single-and two-element antenna arrays are designed and fabricated on a Roger RT/Duroid 5880 substrate with dielectric constant of 2.2, thickness of 1.5748mm, and tan δ = 0.001. The measured results show that a reduction in mutual coupling of 36 dB is achieved at the first band (1.68-2.65) GHz and 22.1 dB over the second band (6.5-8.86) GHz due to introducing electromagnetic bandgap (EBG) structures. EBG structure has an eagle-like shape with more gaps. By increasing the number of EBG cells and varying the gap distance between cells to certain limit, the mutual coupling reduction is improved. Also, a size reduction of 80% is achieved. The microstrip array was simulated by CST simulator version 2014 and fabricated by proto laser machine with precision 25 μm. The specific absorption rate (SAR) investigation is carried out on CST2014 Simulator. Maximum SAR value is 1.953 W/kg which indicates that the eagle-shaped microstrip wearable antennas are safe for human. The antennas can be used in the official or RFID applications.