Design and Analysis of a Miniaturized Planar Triple- Band (28/38/43 GHz) Antenna with Hybrid-Ring Defected Ground Structure for 5G Applications

Abstract

This article describes a compact planar microstrip patch antenna with tri-band functionality at 28 GHz, 38 GHz, and 43 GHz, suitable for 5G millimeter-wave applications. By incorporating a 43 GHz band, the antenna covers additional high-frequency applications like high-capacity backhaul and upcoming B5G/6G systems. The design uses a Hybrid-Ring Defected Ground Structure (HR-DGS) in combination with a slot-loaded radiating patch, which facilitates better control of surface current distribution and multiple resonant modes in a miniaturized design. The antenna uses a Rogers RT/Duroid 5880 substrate, which has εr = 2.2 and tan δ = 0.0009, providing low dielectric loss at high frequencies. The electromagnetic design simulations were carried out in ANSYS HFSS and confirmed the triple-band operation with reflection coefficients of −22.56 dB, −23.49 dB, and −14.43 dB at 28 GHz, 38 GHz, and 43 GHz, respectively. CST Microwave Studio was used to verify the simulated S-parameter response. The simulated gains at the three operational bands were 6.33 dBi, 4.20 dBi, and 4.71 dBi, with the radiation efficiencies of 87.11%, 84.30%, and 89.12%, indicating good performance for the specified frequency bands. The antenna is just 4 × 5 × 0.787 mm³. The combination of size, the simplicity of the HR-DGS design, and the antenna's improved multiband functionality and surface-wave suppression makes it a suitable solution for 5G millimeter-wave systems.