High-Gain MIMO Antenna With Broad Beam Scan Range Using Anisotropic Planar Meta-Lens Array for Millimeter-Wave-Band 5G Applications

This letter presents a multiple-input--mutiple-output (MIMO) antenna system utilizing a bow-tie antenna integrated with a uniquely designed planar multilayer meta-lens array (PMLMLA) to shorten the half power beam width (HPBW) in both the planes for millimeter-wave band [(24 to 32) GHz] applications. The MIMO system comprises eight antenna elements, arranged in a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ {\text {45}}^\circ$</tex-math></inline-formula> angular position to achieve a pattern diversity and enhanced beam scan angle in the azimuth plane. The PMLMLA comprises three layers consisting of an array of anisotropic unit cells inherent with biaxial properties loaded on the antenna. This property leads to confine the radiation beam in the E-plane (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ 26^{\circ }$</tex-math></inline-formula> <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ \pm$</tex-math></inline-formula> <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ 2^{\circ }$</tex-math></inline-formula>) and the H-plane (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ 30^{\circ }$</tex-math></inline-formula> <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ 2^{\circ }$</tex-math></inline-formula>) simultaneously with a peak gain of 11.4 dBi and 10.3 dBi at 28 GHz, respectively. The gain is enhanced by >90% with 1 dB gain bandwidth (GBW) 37% in the desired band, which ensures better pattern integrity behavior. To demonstrate the idea, the antenna is printed and tested.