High Gain Metamaterial Loaded Antipodal Tapered Slot Antenna for Millimeter Wave Applications

Abstract

We propose a novel compact antipodal elliptically tapered slot antenna loaded with left-handed metamaterial over 20-40 GHz for millimetre wave applications. The conventional antipodal tapered slot antenna is modified by incorporating a novel transition between the feed and taper section of the antenna to stabilize the radiation pattern in E-plane and to reduce the beam tilting. We employ a semi-dodecagon shaped dielectric lens with unit cells of a novel broadband metamaterial placed on it to improve the gain of the proposed antenna. The proposed antenna is designed on Rogers RT/Duroid 5880 substrate with dielectric constant of 2.2. The antenna is compact with a volume of $ 30\times 49\times$ 0.254 $\mathrm{m}\mathrm{m}^{3}$. The antenna reflection coefficient $(|\mathrm{S}_{11}|\lt -10\mathrm{d}\mathrm{B})$ shows good impedance matching over a wide frequency range of 20-40GHz. We exploit the left-handedness of the proposed broadband metamaterial structure to guide the electromagnetic waves along end-fire which results in gain enhancement up to 13.78 dB at the highest frequency (40GHz). The proposed antenna exhibits high gain, small area and stable radiation pattern as compared to other state-of-the-art designs.