A Compact Circularly Polarized Implantable Antenna for Wireless Medical Telemetry

A novel miniaturized circularly polarized (CP) patch antenna operating at 915MHz ISM band is designed in this work for wireless biomedical communication. By taking advantage of loading stubs, the proposed antenna features a good miniaturization with the compact size of 13.88×13.88×1.27mm³. A pair of truncated corners in diagonal directions of the planar patch are used for the generation of circular polarization. The simulated 3-dB axial-ratio(AR) bandwidths of around 16MHz is achieved for the proposed antenna, while the impedance bandwidth is 47MHz for |S₁₁| less than -10 dB.