A Miniaturized Triple-Band MIMO Antenna With Dual-Band Circular Polarization for Leadless Pacemaker

This letter presents the development of a triple-band multiple-input-multiple-output implantable antenna with dual-band circular polarization (CP) performance for leadless pacemakers. The proposed antenna operates across the Industrial, Scientific, and Medical band (2.4 GHz to 2.48 GHz), Midfield band (1.5 GHz to 1.75 GHz), and Wireless Medical Telemetry Service band (608 MHz to 614 MHz), respectively. In addition, the designed antenna features a symmetrical and compact structure that is constructed within a leadless pacemaker and optimized in a realistic human heart phantom. Simulation results demonstrate that the designed antenna achieves impedance bandwidths of 13.33%, 12.5%, and 33.33%, with peak realized gains of -28.9 dBi, -38.4 dBi, and -41.7 dBi at 2.45 GHz, 1.65 GHz, and 610 MHz, respectively. Moreover, the antenna exhibits left-handed CP functionality at 2.45 GHz and 1.65 GHz. Finally, the proposed antenna is fabricated and measured in the minced pork, which verifies the simulated results.