Design and Analysis of Linear to Circular Polarization Converter With Third-Order Meta-Frequency Selective Surfaces
Fuheng Zhang, Guo‐Min Yang, Ya‐Qiu Jin
Abstract
This article introduces a novel ultrathin linear-to-circular polarization converter based on third-order meta-frequency selective surfaces (meta-FSS) that operates at the X-band. The meta-FSS unit cell is composed of three metal layers and is separated by two dielectric substrates with a thickness of λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> /20 (λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free space wavelength at 9.8 GHz). The transmission coefficients at two orthogonal directions are equal, while a 90° transmission phase difference is introduced between them over a wide bandwidth. A detailed procedure of equivalent circuit design has been developed for a better understanding of the operating principles. A horn antenna is employed as a linear source to verify the performance of the proposed structure. The measured results show that the designed meta-FSS can effectively convert a linear polarized (LP) wave to a left-hand circular polarized (LHCP) wave in the frequency range 9.1-10.82 GHz (approximately 17.5%) and to a right-hand circular polarized (RHCP) wave in the range 8.8-10.9 GHz (approximately 21.4%).