Compact coplanar waveguide fed wideband directional antenna for medical diagnosis

Abstract

This paper presents a compact coplanar waveguide fed antenna for medical diagnosis of the human head. Early diagnosis of the sophisticated organs inside the human body is possible through microwave medical imaging, which has recently achieved its popularity due to its numerous advantages. The crucial functional element for microwave medical imaging is the antenna. The antenna presented in this paper is conceived and evaluated in contact with an inhomogeneous human head tissue medium, increasing the signal penetration by removing the antenna–air–tissue transition loss. A combination of a meandered line and circular slot are utilized to achieve wideband performance at a subwavelength size. A rectangular cavity is introduced at the back of the antenna to attain directional radiation towards the inhomogeneous human head phantom. The antenna achieves increased bandwidth covering the lower microwave frequency region for medical diagnosis of a human head while minimizing ill-directed radiated fields which interfere with imaging computations. The salient characteristics of compact size, high near-field directionality, lower microwave operating frequency range and low impact on the skin surface make the proposed antenna a suitable candidate for microwave imaging of the human head.