UNIDIRECTIONAL UWB MAGNETO-ELECTRIC ANTENNA FOR MEDICAL TELEMETRY

An implantable magneto-electric antenna (IMEA) aiming for operation at ultra-wideband (UWB: 3.1–10.6 GHz) frequency spectrum is presented for biotelemetry usages for the first time. The IMEA is composed of a horizontal planar bowtie radiator, from which its middle part excites the antenna, and a vertically inclined rectangular radiator. The two radiators are complementary and correspond to electric and magnetic dipoles, respectively. The radiators are built over a square dielectric material (εr = 6, σ = 0.0005) with a cavity for embedding suitable accompanying circuitry system. The IMEA with its biocompatible insulator (PEEK: εr = 3.2, tan δ = 0.01) measures 1456 mm3 in volume. HFSS software was used to carry out numerical optimization of the IMEA with a simple multilayered model of body tissue (Skin, Fat and Muscle) as the host environment. The simulated result of the proposed IMEA shows over 90% impedance bandwidth (S11 < −10 dB) and records a remarkable high gain of 2 dBi within 70% bandwidth. The radiation efficiency is around 50%, and a unidirectional radiation pattern with little back lobe is observed.