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A simple design of a triple-band multi-polarization reflective polarization converter is presented. The proposed device consists of a modified split-ring structure and a cut-wire resonator. A linearly polarized (LP) incident electromagnetic (EM) wave can be reflected into an orthogonally directed LP wave in two widebands and a circularly polarized (CP) wave in one wideband. The triple-band multi-polarization conversion performance is achieved by combing multiple plasmon resonances, which can be controlled by adjusting the parameters of the modified split-ring structure and the cut-wire resonator independently. The simulations show that a y/x-polarized incident EM wave can be rotated to an x/y-polarized reflected wave from 5.75–9.40 GHz (a fractional bandwidth of 48.18%) and 14.22–16.28 GHz (a fractional bandwidth of 13.51%) with a polarization conversion ratio over 0.9. Besides, a CP reflection is obtained from 10.58–13.88 GHz (a fractional bandwidth of 26.98%) with an axial ratio of less than 3 dB. The device is prototyped and a good agreement between experimental and simulated results is obtained. The proposed multi-functional polarization converter yields a wideband in each polarization conversion band and can be extended to work in other frequency bands. [ABSTRACT FROM AUTHOR]

In this letter, a low‐profile low‐sidelobe beam steering metasurface lens (metalens) is presented. The proposed metalens achieves asymmetric polarization conversion using only a single layer with a low profile. Aiming at the metalens, a modified Taylor synthesis method for amplitude modulation is proposed, which reduces the sidelobe level (SLL) while the beam is tilted. Compared with the previous beam steering metasurface, it has a low profile and SLL. The experimental results are in good agreement with the simulated ones. [ABSTRACT FROM AUTHOR]

A metasurface‐based broadband reflective polarisation converter with dual L‐shaped patches and dual trapezoidal patches for linear‐to‐linear polarisation conversion and linear‐to‐circular polarisation conversion is proposed in this study. The simulated and measured results demonstrate that the polarisation rotation can be effectively implemented in the frequency bands 9.24–12.25 GHz and 21.23–23.01 GHz, with the fractional bandwidth of the former being 28.01%. In addition, linear‐to‐circular polarisation conversion is performed with fractional bandwidths of 42.86% and 14.49% at 13.09–20.23 GHz and 23.62–27.31 GHz respectively. In the primary bands of linear‐to‐linear polarisation conversion and linear‐to‐circular polarisation conversion, the converter can operate within an incident angle range of 55° for polarised wave. This design may have potential uses in polarisation control devices used in the field of communications in X‐, Ku‐ and K‐bands. [ABSTRACT FROM AUTHOR]

A novel and simple low-profile high-gain wideband circularly polarized (CP) slot antenna with low radar cross section (RCS) is presented. The proposed antenna is composed of a traditional linearly polarized (LP) slot antenna and an integrated metasurface-based superstrate. The superstrate consists of a center array with metasurface (MS) unit cells and four surrounding arrays with 4×4 MS unit cells. On the one hand, a wideband and high-gain CP radiation in the frequency band of 5.27-6.18 GHz (a relative bandwidth of 15.9%) is achieved by the polarization conversion property of the MS and four surrounding arrays. On the other hand, a broadband RCS reduction in the frequency band of 4.5-20 GHz (a relative bandwidth of 126.5%) is obtained by the combination of two electromagnetic wave diffusion principles. Inspired by C-band, X-band and Ku-band radar applications, a low-cost stealthy prototype with broadband low RCS and CP radiation is realized. [ABSTRACT FROM AUTHOR]

Based on characteristic mode analysis (CMA), a novel method for reshaping the TM00 mode of the rectangular patch antenna (RPA) is presented. Initially, the RPA loaded by periodic shorting vias, as the basic structure for generating the TM00 mode, is investigated by CMA. The nonbroadside pattern of TM00 mode is revealed to be caused by the vertical currents on the shorting vias. And it can be transformed into a broadside direction by replacing the vertical vias with a new shorting structure possessing strong horizontal currents. Moreover, to further verify the feasibility of the proposed method, a compact CPW‐fed aperture‐coupled RPA for the WLAN application is designed. By simultaneously exciting a reshaped TM00 mode, a fundamental TM10 mode, and a slot mode, the proposed RPA can achieve dual‐band performance with broadside radiation features. Finally, the proposed antenna is fabricated and tested. The results illustrate that the fabricated antenna can achieve good impedance matching and broadside radiation characteristics in 2.4–2.46 GHz and 5.1–5.6 GHz bands. [ABSTRACT FROM AUTHOR]