Meander-Lined Implantable Antenna Design at 2.45 GHz Using Transmission Line Model

Abstract

Scientists mostly follow a trial-and-error approach using simulators for designing implantable antennas which may increase time complexity and memory usage. In this article, the Transmission Line Model (TLM) is utilized to design a miniaturized meander-line implantable antenna at 2.45 GHz for reducing time and memory requirements. The meander-line antenna is first decomposed into different segments – x-directed, y-directed, and bends. Each segment is considered a transmission line and each line is replaced by its equivalent lumped LC network. The lumped parameters are calculated using the dimensions of the segment and guided wavelength inside the body. Here, a three-layered body model is represented by a T-type resistor, inductor and capacitor (RLC) network. The antenna within the human body is then simulated using Finite Element Method (FEM)-based CST Microwave Studio software. FEM technique is taking 4.94-MB memory space and 13-minutes time to analyze this implanted system whereas TLM is analyzing the same system by considering 726-KB memory within 52 s. TLM is predicting implanted antenna performance considering ∼0.8% error concerning simulated response. The designed antenna is fabricated and measured within a homogeneous body phantom and minced pork to verify the simulated response. The effect of chamfering of the corners of the meander-line antenna is also analyzed here. From this study, it is observed that TLM can predict implantable antenna response efficiently with low memory and less time requirement with respect to FEM which is helpful for antenna engineers. Analysis of implantable antenna with low memory and time requirements using TLM is a novel approach to this work.