A Single-Layer Planar Low-Profile Wideband Microstrip Line-Fed Metasurface Antenna

A single-layer, planar wideband microstrip line (ML) fed metasurface-based antenna operating at 5 GHz wireless local area network band is proposed. It is composed of an array of 3 ×3 square metal patches fed by an ML connected to the central patch of the three peripheral unit cells. To reduce the phase delay between the driven patch and the parasitic patches placed along the E-plane, a large square slot is cut on the fed patch, while the patches on the second and third rows are sliced into smaller ones to stabilize the patterns at higher frequencies. The large slot also helps achieve better impedance matching.
T
M
₀₁
and
T
M
₂₁
modes are excited, giving a measured - 10
dB
bandwidth of 26.56% (5.06-6.61 GHz). The compact size of 1λ
₀
×1.1λ
₀
×0.058λ
₀
(λ
₀
is the free-space wavelength at the center of the frequency band), stable boresight patterns, low profile, planar configuration, and wide bandwidth features make the presented antenna attractive for various wireless systems.