A miniaturized tunable microstrip antenna for wireless communications with implanted medical devices

Abstract

In this paper, a miniaturized microstrip antenna design is presented for establishing wireless communications with implantable medical devices in the 402-405 MHz Medical Implant Communications Services (MICS). The Ansoft's High Frequency Structure Simulator (HFSS) and CST Microwave Studio were used to evaluate the antenna design. HFSS is based on the Finite Element Method (FEM) and Microwave Studio is based on the Finite Difference Time Domain (FDTD) technique. The results from both simulations are compared to validate results obtained from the two software packages. A varactor diode is added to allow tuning of the antenna. Size reduction techniques such as meandering, addition of a shorting pin, and the introduction of a capacitive plate were investigated to make the antenna size suitable for use with medical implants.