Antipodal Vivaldi Antenna with Dielectric Lens for Biomedical Imaging Applications

This paper presents the antipodal Vivaldi antenna (AVA) with dielectric lens. The AVA which efficiently focuses the energy toward the end-fire direction is required for biomedical applications. For this purpose, the various shapes of dielectric lens i.e., rectangular, triangular, trapezoid, sine, and elliptical-shaped dielectric lens as an extension of dielectric substrate are proposed. The effects of different dielectric lens shapes on enhancement of the gain and electric field in near field region are investigated. In order to confirm the validate in the designing, the AVA with elliptical dielectric lens is fabricated with the dimension of 45 mm × 90 mm. The measured results show that the proposed antenna can provide wide impedance bandwidth, covering the frequency range from 3.06 GHz to over 10 GHz. The proposed antenna has a maximum gain of 13.18 dBi at 10 GHz.