Numerical Study of an Ultra-wideband Low Profile Polarization Converting Metasurface for Millimeter Waves

This paper presents an ultra-wideband polarization converting metasurface (PCM) for millimeter wave which can manipulate the linear polarized (LP) incident wave to its orthogonal counterpart in the frequency range of 49.7 to 142.2 GHz with an ultra-wide bandwidth of 92.5 GHz and a fractional bandwidth (FBW) of 96%. The proposed PCM shows outstanding results in achieving higher fractional bandwidth with overall polarization conversion ratio (PCR) > 90% in the desired band. The proposed PCM has low profile dimensions with thickness and periodicity of 0.5 mm (0.083 λ o ) and 1.43 mm (0.24 λ o ), where λ o is the maximum wavelength at the lower operating frequency. Surface current distribution is studied to show the physics of polarization conversion. The design is versatile and adoptable in low-profile applications where minimum thickness is required and can be utilized in remote sensing, microwave relays, and astronomy.