![]() ![]() In recent years, to improve the practical applicability of polarization converters, high-efficiency multiband polarization converter has become a research hotspot. In 2015, an invertible linear-to-circular polarization converter was proposed by Li et al., which can transform a circularly polarized wave into a linearly polarized one or a linearly polarized wave into a circularly polarized wave in transmission mode. circular polarization converters have been extensively investigated. In addition, since the circular polarization has advantages of mitigation of multipath fading, immunity of “Faraday rotation” and the reduction of polarization mismatching, 36 36. After that, a four-layered polarization rotator with two pairs of L-shaped metallic patterns has been proposed by Jia et al., which can realize a polarization conversion ratio higher than 90% in the frequency range of 7.8 GHz to 34.7 GHz. proposed a polarization converter based on double V-shaped metasurface, which can convert linearly polarized waves into cross-polarized waves in ultra-wideband from 12.4 GHz to 27.96 GHz. It has been proved that high-efficiency and wideband polarization converters can be achieved by tailoring the geometry of the resonators in an array. ![]() The latter approach for the polarization conversion is based on the reflection (transmission) phase difference in two orthogonal polarizations. realized a 90° polarization rotator by using a bilayer chiral metamaterial, which is independent on the incident polarization angle. realized asymmetric transmission of circularly polarized terahertz waves through planar chiral MMs. So far, many polarization converters of asymmetric transmission have been extensively investigated based on MMs, showing outstanding potential in many fields such as beam splitters, circulators and sensor components. The existing literatures indicate that the former is convenient for designing transmissive polarization converters. Generally speaking, metamaterial polarization converters can be realized in the following two ways: one is by using chiral MMs and the other is to use anisotropic MMs. Owing to the lower profile of MMs, they are easy to integrate into ultrathin devices. #DOUBLE ANGLE OF REFLECTION FULL#In the past few years, full control of the polarization states of EM waves has made significant progress based on MMs. ![]() So far, MMs have been widely approved effective in controlling the polarizations of EM waves due to its exotic properties. Recently, metamaterials (MMs), a kind of artificially designed structures possessing the extraordinary properties that can’t be found in nature, have been proposed as an alternative solution to control EM waves. However, these materials are usually challenging to be applied in practical systems due to their bulky size and narrow frequency response. and solid or liquid crystals are often used to achieve the effect. The traditional way of manipulating EM wave polarizations is often based on the birefringence effect of materials, 6,7 6. The effective control of the EM wave polarization states is important because of its potential applications in wireless communications, imaging, radar stealth technology, 2–5 2. The polarization of electromagnetic (EM) waves refers to the trace of the electric field in a plane perpendicular to the propagation direction. ![]()
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