Ultra-Compact Implantable MIMO Antenna for High-Data-Rate Bio-Telemetry Communication

This work presents the development of an ultra-compact highly isolated two-element implantable Multiple-Input-Multiple-Output (MIMO) antenna for high-data-rate bio-telemetry communication. The antenna operates in the Industrial, Scientific, and Medical (ISM) frequency band at 2.45 and 5.65 GHz. The proposed antenna occupies a very compact size of 3.1075 mm
³
, which is one of the smallest proposed implantable MIMO antennas in the literature to the best of our knowledge. The low volume of the antenna was achieved by printing meandered-line resonators on top of a high dielectric substrate
$(\epsilon_{r}=\text{10.2})$
. A dual-band operation was achieved for port-1 at 2.45 and 4.65 GHz with a fractional bandwidth of 17.4% and 14.8%, respectively. Additionally, port-2 achieved a bandwidth of 15.5% at 5.65 GHz. The achieved peak gains are -18.1 and -21.4 dBi for port-1 and port-2, respectively. Specific absorption rate and link budget analyses were conducted and revealed the antenna's ability to perform bio-telemetry communication with high-data-rates of up to 100 Mbps while satisfying power safety regulations.