Resonance Sensitivity and Quality Factor of Implantable Loop Antenna Loaded with Interdigital Capacitor in the Cerebral Spinal Fluid

摘要

The design of an implantable loop antenna loaded with an interdigital capacitor operating at 400 MHz is presented. The sensitivity of the resonance change due to the change of the dielectric constant of the implantation tissue is studied and assessed via numerical simulations. The perturbation of the electric field affects the capacitance and thereby the input impedance of the antenna. In this manner, the antenna can be used to sense the dielectric constant changes of the implantation tissue. Despite the adverse effect of the cerebral spinal fluid (CSF) on the quality factor (Q) of the implantable antenna, a resonance shift of 25.2 MHz is obtained when the dielectric constant is increased by 14% from the nominal values.