Tri-Band Wearable SIW Textile Antenna With Metasurface for Wireless Body Area Network

In this letter, a tri-band on-body/off-body wearable substrate integrated waveguide (SIW) textile antenna operating in the World Interoperability for Microwave Access (WiMAX) band (2.3–2.69 GHz; 3.3–3.8 GHz) and WLAN band (5.15–5.825 GHz) is proposed. The antenna uses a SIW resonant cavity, which allows multiple frequency points to be excited to achieve multi-frequency characteristics, and a layer of metasurface (MS) structure is added to adjust the resonant frequency points and impedance bandwidth. The final results show that the antenna performance is good, the measured results are consistent with the simulated results, the peak gain is 9.27 dBi, the antenna creates the omnidirectional and unidirectional radiation patterns very well, in addition, its wearable performance is good, in the human body and the free space measured data is basically the same, using the three-layer human body tissue model to calculate the antenna's Specific Absorption Rate (SAR) value, and the calculation result is lower than the upper limit of the United States and the European Union standards, These characteristics indicate that the antenna can be used in wearable systems.