On the use of graphene for quad-band THz microstrip antenna array with diversity reception for biomedical applications

A graphene-based Terahertz (THz) diversity antenna using a series-fed microstrip antenna array is reported in this paper for body-worn applications under biomedical conditions. The proposed series-fed antenna array is constructed using a quad-band radiator. Each array comprises two quad-band elements, and two such arrays are developed to create the THz antenna array with diversity reception. The proposed diversity antenna has an overall footprint of 40 × 28 μm. The proposed array operates at 1.57 THz, 2.08 THz, 3.32 THz and 4.43 THz with 10 dB reflection coefficient bandwidth of 29 GHz, 49 GHz, 55 GHz and 99 GHz, respectively. The antenna elements are spaced at a distance of 26 μm to achieve mutual coupling less than − 25 dB. The realized antenna gain is 4.5 dBi, 4.8 dBi, 5 dBi, 5.2 dBi at 1.57 THz, 2.08 THz, 3.32 THz and 4.43 THz, respectively. The diversity metrics such as envelope correlation coefficient, adaptive diversity gain, effective diversity gain, mean effective gain and the cumulative distribution function are evaluated and presented. The results indicate that the proposed two-element antenna array is a suitable candidate for diversity reception in wireless body area networks operating in the THz regime.