A Sierpinski Arrowhead Curve Slot Vivaldi Antenna for Microwave Head Imaging System

Abstract

The development of antipodal Vivaldi antenna with a fractal slot is presented in this paper due to its promising application as an element of possible multisensory systems of head stroke imaging. The fractal slot is applied to improve the directivity, bandwidth and gain of the antenna. Hence, this research mainly aims to create and optimise a compact Vivaldi antenna through the fractal slot for the detection of stroke in the human head. The antenna is designed with an overall dimension of 65 × 65 × 1.6 mm 3 using Roger RO4350B as a substrate through the CST Studio Suite 2019 software. The proposed antenna will also be compared with an antipodal Vivaldi antenna without the fractal slot to observe differences in the result. The proposed antenna can produce a wide bandwidth of 1.44 GHz ranging from 2.35 GHz to 3.79 GHz at the maximum gain of 7.35 dBi. Furthermore, the prototype antenna has a directivity characteristic, which produces the unidirectional radiation necessary for microwave imaging procedures. The proposed antenna is also evaluated with the CST studio head model, thus providing satisfactory penetration results through the head tissue. A value of 0.0013 W/kg per 10 g is achieved for the maximum SAR. Thus, the proposed antenna met most of the requirements for the imaging process, which will affect its effectiveness during scanning of head stroke. Fractal slot, Vivaldi antenna, wideband, unidirectional, head imaging. INDEX TERMS

Design of Antipodal Vivaldi Antenna for Medical Imaging Application

“…To simulate these irregularities and facilitate detection testing, a method based on the difference in relative A B C D permittivity values between water and air anomalies was employed. The relative permittivity value of the air anomaly is significantly lower than that of water, making it easier for the antenna to detect and causing a shift in the S-parameter values [32,33]. The coordinate points representing this shift are presented in Table 4.…”