Reduction of detuning effects using robust parameter design for implantable antennas

A new design framework for implantable antennas to reduce detuning effects due to various dielectric properties is presented. Conventionally, in order to overcome the detuning effects, it is highly demanded to have a broadband impedance matching to compensate the frequency shift. However, achieving a wider impedance bandwidth leads to larger antenna dimensions, and lack a mathematical treatment to optimise implantable antennas against the variation of tissue properties to date. A new methodology based on robust parameter design is proposed to cope with the detuning effects. Instead of designing the antenna in one single tissue environment, the proposed technique analyses the variation of dielectric properties in distinct tissue environments. The optimised performances show that robust impedance matching in the medical implant communication services band is achieved, although the dielectric constant varies from 35 to 55. Simulated and measured results are presented to demonstrate the validity of the proposed design methodology.