Design and Analysis of 38GHz mmWave Modified MIMO Antenna on Low Permittivity Substrate for 5G Ka Band Applications

This study focuses on the design of a two-port MIMO antenna operating at 38.00GHz in the Ka Band of FR2 in mmWave spectrum, designed using FR4 epoxy dielectric substrate. The single-element of this 2-Port MIMO antenna occupy a volume of 6.2×7.4×l.0mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>(L×W×H). The single element design is enhanced using two rectangular slots on the rectangular patch and the ground plane on the opposite side is enhanced using a circular slot, enabling resonance of this enhanced single element at 39.00GHz. The compact two-port MIMO antenna is designed using this single element structure with a total volume of 6.2xl0.4xl.0mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>(LxWxH) and an inter-element spacing of 2.70mm. The optimization through parametric analysis and enhancement by creating two additional rectangular slots on the ground element are used to reach narrow-bandwidth characteristics with high impedance matching achieved at 38.00GHz. The rectangular patch has a dimension 3.5×2.5mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. The enhanced 2-Port MIMO antenna demonstrates a peak gain of 4.02dBi and a radiation efficiency of 91% at the resonant frequency(38.00GHz), while maintaining a stable radiation pattern in E and H plane. Diversity performance analysis of enhanced 2-Port MIMO provides <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{ECC}_{38.00\text{GHz}} &lt; 0.0075,\text{DG}_{38.00\text{GKz}} &gt; 9.9996,\text{TARC}_{38.00\text{GHz}}=-20.25\text{dB}$</tex>, MEG1- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{MEG}_{28.00\text{GHz}} &lt; 0.40\text{db})$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{CCL}_{38.00\text{GHz}} &lt; 0.25\mathrm{b}/\sec/\text{Hz}$</tex> in proposed bandwidth, indicating its suitability for compact 5G devices in Ka band applications.