Design and Investigation of Orthogonal Hybrid Dual-Mode Single-CDR-Based MIMO Antenna With High Self-Isolation at 5.8GHz
Samira Mekki, Atul Varshney, Djamel Sayad, Issa Elfergani, Hanane Bendjedi, Mohamed Lamine Bouknia, Rami Zegadi, Jonathan Rodrı́guez, Merih Palandöken, Kâmil Karaçuha, Chemseddine Zebiri
Abstract
In this article, a dual-port single-element coaxial probe-fed cylindrical dielectric resonator MIMO antenna is designed and investigated. The high-permittivity dielectric (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\varepsilon }_{\mathrm {r}}=15$ </tex-math></inline-formula>) is composed of barium-titanate-doped polydimethylsiloxane (PDMS) silicone polymer. The orthogonal excited antenna generates orthogonal modes (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm {H}\mathrm {E}_{11\delta }^{\mathrm {x}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm {H}\mathrm {E}_{11\delta }^{\mathrm {y}}$ </tex-math></inline-formula>) with high port-to-port self-isolation (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lt -21$ </tex-math></inline-formula> dB) without additional mutual coupling reduction structures. The antenna achieved bandwidths are 5.65–5.96 GHz (gain: 8.91 dBi) and 5.62–5.92 GHz (gain: 8.97 dBi) for Port1 and Port2, respectively. It has an axial ratio >26.5 dB, ensuring orthogonal linear polarization characteristics and improved isolation. The antenna attains excellent MIMO parameters; TARC <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lt -10$ </tex-math></inline-formula> dB, VSWR-MIMO <2, ECC <0.24, DG <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim ~10$ </tex-math></inline-formula> dB, CCL <0.4 bits/sec/Hz, and MEG <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lt \pm 3$ </tex-math></inline-formula> dB in operating bandwidth. The HFSS simulated and investigated performance parameters of the MIMO antenna are found to be in excellent agreement with experimental data, this validates the antenna’s MIMO functionality. The antenna is modeled as a parallel RLC equivalent circuit in ADS using a novel technique based on complex-valued impedance parameters (Zij). This approach demonstrates improved accuracy, validated by both simulations and measurements. The antenna is suitable for ISM (5.725–5.85 GHz), WLAN 5.8 GHz, C-band (5.0–6.0 GHz).