A Wideband Quasi-Isotropic Biconical Antenna with Plano-Concave Lens for IoT Based Smart Applications

Abstract

A wideband quasi-isotropic planar biconical antenna with plano-concave lens is designed for IoT applications. The antenna is realized using a broadband planar biconical dipole and a pair of plano-concave lenses. The cones of biconical dipole are placed at 70◦ angular separation for least gain deviation (GD) across the radiating sphere. A pair of plano-concave lenses suppress GD in elevation plane and improve the impedance matching bandwidth (IBW). Different design parameters are analyzed for wide IBW and 7 dB gain deviation bandwidth (GBW). The designed antenna dimensions are 0.25λ<inf>o</inf> × 0.3λ<inf>o</inf> × 0.004λ<inf>o</inf> at 2.35 GHz. The proposed antenna provides 71.6% (1.51–3.2 GHz) IBW and 73.6% (1.5–3.25 GHz) 7 dB GBW. Experimental results are in good agreement with the simulated ones. The proposed antenna is suitable for IoT based smart applications, energy harvesting, and 5G cellular communication. © 2025 Elsevier B.V., All rights reserved.