Open AccessCompact Modified Mikaelian GRIN Lens Antenna with Gain and Bandwidth Improvement
Author(s) -
Andrzej Dudek,
Slawomir Gruszczynski,
Krzysztof Wincza
Publication year - 2025
Publication title -
ieee antennas and wireless propagation letters
Language(s) - English
Resource type - Magazines
SCImago Journal Rank - 1.328
H-Index - 117
eISSN - 1548-5757
pISSN - 1536-1225
DOI - 10.1109/lawp.2025.3572633
Subject(s) - fields, waves and electromagnetics
This letter proposes a compact Mikaelian lens antenna (LA). The proposed antenna consists of an aperture-coupled patch (ACP) antenna with a patch printed directly on a graded refractive index (GRIN) lens. By loading the ACP antenna with the dielectric lens, the antenna impedance bandwidth increases from 17.5% to 33%. In addition, the lens refractive index (RI) profile is angularly modified with the use of $cos(2\phi)$ function to improve the radiation pattern and gain of the LA to achieve the maximum theoretical aperture efficiency (AE) of 116% at 24 GHz. The proposed concept was validated in simulations and measurements of the LA operating in the 23–34.5 GHz frequency range. The fabricated LA has a volume of $2\lambda \times 2\lambda \times 1.76\lambda$ at 24 GHz. It achieves a maximum AE of 58% at 23.5 GHz for gain of 13.7 dBi, which could be improved to 96% with the use of low-loss materials.