Electrical characteristic changes by setting conditions of Normal-Mode Helical Antenna in a phantom

Normal-Mode Helical Antenna (NMHA) is a promising candidate for medical implantable application due to its ability to achieve high efficiency in very small size, when self-resonant structure of the antenna is achieved. In use of NMHA for implantable application, a human body phantom is employed in antenna development stage. In the case of measurement of NMHA placed in a phantom, antenna setting and feeder cable may influence measured results. In this paper, relations of antenna setting conditions and measured electric characteristics such as antenna input impedance and radiation patterns are clarified through electromagnetic simulations