An Ultra-Wideband Linear-to-Circular Polarization Converter Based on a Circular, Pie-Shaped Reflective Metasurface
Abdul Majeed, Jinling Zhang, Muhammad Aqueel Ashraf, Saifullah Memon, Khalid Hussain Mohammadani, Muhammad Ishfaq, Mun Sun
Abstract
In this paper, we present an ultrawideband reflective metasurface with the properties of an LTC-PC, which is an orthotropic composition with two mutually orthogonal symmetric axes, v and u, and 45° rotation about the vertical y-axis. Based on the metasurface unit cell, it seems like a circular pie embedded with a rectangular patch. The converter can convert LP electromagnetic (EM) waves to CP waves over the bands from 20.18 GHz to 33.93 GHz, with a 3-dB AR bandwidth of up to 50.8% and a circular polarization wave that is RHCP (right hand CP). Moreover, the linear-to-circular PCR exceeds 98% in the frequency bands of 20–34 GHz. A comprehensive theoretical investigation was conducted to determine the fundamental cause of the LTC polarization conversion. The ∆φuv between two reflection coefficients at v- and u-polarized incidences is ±90°, which fully anticipates the axial ratio of the reflected wave. Any reflective metasurface can be used as an efficient LTC-PC if the ∆φuv is close to ±90°.