Circularly polarized implantable MIMO antenna for skin, brain and heart implantation with wide axial ratio bandwidth

A unique MIMO antenna with circular polarization characteristics that works similarly for skin, brain and heart phantoms has been proposed in this paper. The twin rectangular X-shaped slot that serves as the basic structure of the proposed antenna is entirely planar and low-profile but has a defective ground plane. For three different phantoms, the proposed antenna resonates at 2.4-2.45 GHz ISM band. With a dimension of 15.5x9x1.27mm3$$ 15.5\times 9\times 1.27\ {\mathrm{mm}}<^>3 $$, the antenna exhibits compactness. Rogers RT/duroid 6010 substrate material has been used to fabricate the antenna in order to validate the designed antenna structure. Utilizing the high dielectric material for both substrate and superstrate, both skin-mimicking gel and minced hog meat were employed in the experiment setup at 2.45 GHz ISM band. At ISM band, -28.3 dBi has been observed has realized peak gain. The obtained fractional bandwidth (FBW) and Axial Ratio Bandwidth (ARBW) values are 30.67% and 45%, respectively. Also, the maximum specific absorption rate (SAR) values are found to be in the acceptable limit regulated by IEEE. A low profile circularly polarized implantable MIMO antenna is designed for bio-telemetry applications. This antenna is operating at the frequency of 2.45 GHZ ISM band. The proposed antenna achieves -28.3 dBi realized peak gain, fractional bandwidth (FBW) and Axial Ratio Bandwidth (ARBW) values are 30.67% and 45%, respectively. image