Miniaturized Wideband Metasurface Antenna Using Fully Multiplexed Structure

A fully multiplexed metasurface (FMMTS) is presented and exploited to engineer a low-profile, compact, and wideband metasurface antenna (MTA). The proposed FMMTS element is constructed by slotting and subdividing a conventional hexagonal radiating patch into three congruent diamond-shaped segments, with each one being shared by adjacent elements. This full-reusing configuration drastically enhances spatial efficiency. Additionally, the increased inter-unit gaps lead to supplementary edge capacitances, which effectively lower the resonance frequency of the FMMTS radiator, allowing for a more compact radiation aperture. Then, the FMMTS array is modified for miniaturization, and the characteristic mode analysis is adopted to explain its mechanism. As a proof of concept, the modified FMMTS array is coupled to a T-shaped feeding network through a rectangular aperture, forming a linearly polarized MTA and realizing an impressive impedance bandwidth of 57.83% and a peak gain of 6.93 dBi, all within an extremely compact overall size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\text{0.34}}\lambda _{\text{low}}$</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">${\text{0.34}}\lambda _{\text{low}}$</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">${\text{0.035}}\lambda _{\text{low}}$</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">$\lambda _{\text{low}}$</tex-math></inline-formula> is the lower operating wavelength in free space), which shows a size reduction of approximately 50% when compared to recently developed wideband MTAs.