A Low-Profile Multiband Shared-Aperture Antenna Using Multiplexed Metasurface

This letter introduces a multiband low-profile antenna by developing a simple metasurface (MS) and a hybrid feeding. The MS is reused as both a radiator for the y-polarized antenna and an artificial magnetic conductor reflector for the x-polarized antenna, resulting in a low profile of 0.1 lambda at 3.5 GHz through effective stacking. The y-polarized antenna takes the form of an MS-based grid-slotted patch with a wide band of 4.03 GHz to 5.63 GHz (1.6 GHz, 33.1%), while the x-polarized antenna is configured as a dipole with dual bands of 3.36 GHz to 3.70 GHz (0.34 GHz, 9.6%) and 5.14 GHz to 5.58 GHz (0.44 GHz, 8.2%). A defected ground structure is introduced to achieve impedance matching and generate a band notch for the dipole antenna. To address the misalignment of radiation patterns in the high-frequency band of the x-polarized antenna, an asymmetrical slot is employed for pattern correction by 11(o).