Left-hand Circular Polarization Research Articles

Design Approach for Low-Profile Tri-Polarization Patch Antenna With Simultaneous Harmonic Suppression

A novel design approach to achieve harmonic suppression of a low-profile microstrip patch antenna (MPA) under tri-polarization is proposed. Herein, the tri-polarization consists of the left-handed circular polarization (LHCP), right-handed circular polarization (RHCP), and linear-polarization (LP). First, the resonant frequencies of the traditional MPA are deeply studied. It is demonstrated that a set of radiative modes are excited in a single patch resonator. In order to suppress a few undesired modes, an array of shorting vias is loaded around two edges of the quarter patch1. Then, a linear slot is introduced to move dual orthogonal modes closely to each other, resulting in achieving LHCP patterns with harmonic suppression. Similarly, both of RHCP patterns and harmonic suppression are acquired for the quarter patch2 via this method. After that, the shorting vias and slots are adopted on the half patch3, aiming to suppress or push up higher modes for LP generation and harmonic suppression. Lastly, all these three patches are integrated with each other for size reduction. Finally, the proposed MPA is fabricated and measured. The results illustrate that the antenna has satisfactorily gained LHCP, RHCP, and LP radiation patterns of around 2.65 GHz. Besides, the volume of the radiator ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.0058\lambda _{0}^{3}$ </tex-math></inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> is the free-space wavelength) is only half of the traditional counterpart ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.01\lambda _{0}^{3}$ </tex-math></inline-formula> ). Additionally, the port isolation is kept as large as about 22 dB in the operating band. Most importantly, the harmonic suppression of around <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.7~f_{0}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f_{0}$ </tex-math></inline-formula> is the operating frequency) is successfully acquired without extra feeding circuits.

Wideband Circularly Polarized Stacked Patch Antenna Based on TM₁₁ and TM₁₀

A wideband circularly polarized (CP) stacked patch antenna based on TM₁₁ and TM₁₀ is proposed in this article. This four-port antenna consists of a circular patch and a square patch, where the square patch is located above the circular patch. Taking into account the mutual coupling between four ports, the active reflection coefficient (ARC) is adopted to describe the impedance matching of the antenna, and a simplified form of ARC is derived. The abnormal electric field distribution generated in the square patch is attributed to the superposition of the electric fields of two orthogonal TM₁₀ modes, which is theoretically verified. Due to the coupling between TM₁₁ mode and TM₁₀ mode, a new resonance mode appears in a square patch, where the abnormal electric fields on the two diagonals are generated simultaneously. The effect of the square patch on the circular patch is equivalent to a capacitor at the lower frequency end and the higher frequency end of &#x2212;10 dB impedance bandwidth, while it acts as an inductor at the middle frequency band. Besides the horizontal patch of <inline-formula> <tex-math notation="LaTeX">$\lceil $ </tex-math></inline-formula>-shaped feed is sandwiched between two radiators to enhance coupling. Finally, a wideband feed network composed of Wilkinson power divider and phase shifter is devised to provide four signals of equal magnitude and quadrature phase for proposed antenna. To verify the design concept, a prototype is fabricated and measured. The results show that left-hand circularly polarized (LHCP) radiation is achieved. The 3 dB gain variation bandwidth is 44.6&#x0025;, ranging from 1.48 to 2.33 GHz, in which VSWR &#x003C; 1.5 and AR &#x003C; 1.5 dB. Besides the peak gain is 9.5 dBic and antenna efficiency is not less than 64&#x0025;.

Single-Fed Dual-Circularly Polarized Stacked Dielectric Resonator Antenna for K/Ka-Band UAV Satellite Communications

A single-fed dual-band dielectric resonator antenna (DRA) with orthogonal circular polarizations (CPs) in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">K</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ka</i> -bands is proposed for satellite communications on unmanned aerial vehicle (UAV). The antenna overcomes the challenges of dual-band dual-CP operation, narrow axial-ratio bandwidth (ARBW) of single-fed antennas, and limited payload and space of UAVs. A shared-aperture merged-structure technique of DRA and slot-dipole antenna is proposed for dual-band dual-CP radiation, thus enabling full-duplex operation with compact size for high isolation systems. The orthogonal CPs in two frequency bands can be controlled independently by a phase compensation method. Besides, broadened ARBW and enhanced gain are attained from the stacked DR, from which high capacity and reliability communication can be achieved. A prototype operating at right-handed CP (RHCP) in the lower band, whereas left-handed CP (LHCP) in the upper band has been designed and measured. It features 10-dB impedance bandwidths of 6.4% and 12.8%, and 3-dB ARBW of 5.2% and 4.1% in the lower and upper bands, respectively. The antenna provides a low cost solution for high isolation, high throughput, and small payload full-duplex UAV satellite systems.

A Periodic Mirror-Reflected Circular-Polarized Leaky Wave Antenna With Dual-Beam Scanning in Dual Polarization Types

A periodic mirror-reflected circular-polarized (CP) leaky wave antenna (LWA) with dual-beam scanning in dual polarization types is reported in this communication. The unit cell of the proposed antenna consists of two oblique stubs that are orthogonally separated (90°) to create a circular polarization. In order to achieve better CP (axial ratio (AR) < 3 dB) and beam-scanning characteristics for the periodic CP antenna, a new method of adding a groove at the junction of stubs within the unit cell is introduced. To realize dual-beam scanning in dual circular polarization, a metal via is added at the end of the antenna to generate a mirror reflection. A mirror-reflected structure is fabricated and measured. The measured results show that the right-handed CP (RHCP) scanning range of the incident beam is −31° to −8° and 5° to −14°, and the left-handed CP (LHCP) scanning range of the corresponding reflected beam is 31°–6° and −6° to −15°. The measured results are in good agreement with the simulated ones.

Broadband achromatic longitudinal bifocal metalens in the visible range based on a single nanofin unit cell

Metasurfaces provide a remarkable platform to manipulate over phase, amplitude, and polarization flexibly and precisely. Bifocal metalens draws great research interest due to its ability of converging wavefronts to different focal positions horizontally and longitudinally. However, as wavelength of incident light changes, chromatic aberration will cause the focal lengths reliance on the incident wavelength, which will affect the performance of metasurface, especially for longitudinal bifocal metalens. In this work, a broadband achromatic longitudinal bifocal metalens (BALBM) based on single nanofin unit cell is demonstrated. Pancharatnam-Berry (PB) phase is used to converge the incident light. Cross commixed sequence distribution (CCSD) is introduced to control the positions of focal points FLand FRwhen left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) incident. Propagation phase is used to compensate the phase difference caused by chromatic aberration. Simulation results show that in the continuous wavelength range from 500 nm to 700 nm, the focal point shifts caused by chromatic dispersion are reduced 81% for FL and 83% for FR, respectively. The focal length variations are stabilized to 6.21% for FLand 4.8% for FRcomparing with the focal lengths at the initial wavelength 500 nm. The proposed BALBM brings advances to bifocal metasurfaces in versatile application areas including machine vision, optical computed tomography and microimaging.

Optical manipulation of optical vortex beam on gold nanoparticle

ABSTRACT The optomechanical manipulation of an optical vortex beam (Bessel beam) upon a single gold nanoparticle (GNP) was studied theoretically. This structured light carries spin angular momentum (SAM) and orbital angular momentum (OAM) simultaneously via the spin-orbit interaction (SOI) of light. Due to the plasmon-enhanced light absorption and scattering of GNP, the SAM and OAM of photons are transferred to GNP, exhibited by the spin and orbital motions of GNP. The optical force and torque upon GNP are analyzed through the surface integrals of Maxwell's stress tensor. We found that there are specific stable circular orbits of GNP through the simulation of GNP's equation of motion; the revolution direction depends on the sign of the order of Bessel beam. If the order of Bessel beam is a positive integer, the GNP performs an orbital motion with a counterclockwise revolution. On the contrary, for a Bessel beam of a negative order, a clockwise revolution of GNP is induced. Additionally, the spin direction of GNP depends on the handedness of light: right-hand or left-hand circular polarization.

Chiral Hybrid Copper(I) Iodide Single Crystals Enable Highly Selective Ultraviolet-Pumped Circularly Polarized Luminescence Applications.

Light-emitting diodes (LEDs) with the circularly polarized luminescence features have attracted attention to the promising applications ranging from solid-state lighting and displays to bioencoding and anticounterfeiting. The prerequisite of circularly polarized luminescence is highly emissive chiral materials. Here, we demonstrated that (R/S-MBA)4Cu4I8·2H2O (MBA = α-methylbenzylaminium) and acentric Gua6Cu4I10 (Gua = guanidinium) single crystals were grown on the basis of Gua3Cu2I5 by the slow evaporation method. (R/S-MBA)4Cu4I8·2H2O single crystals exhibited excellent circularly polarized luminescence (CPL) characteristics. More importantly, ultraviolet-pumped LEDs (UV-LEDs) based on (R/S-MBA)4Cu4I8·2H2O and Gua6Cu4I10 single crystals exhibit a higher optical selectivity when exposed to right-handed and left-handed circular polarization (RCP and LCP) conditions. (S-MBA)4Cu4I8·2H2O single crystals and Gua6Cu4I10 single crystals induced by the (R)-MBA cation exhibit the different polarized light intensities at PL peak positions in different λ/4 waveplate polarizer angle directions, which provides new possibilities for the further applications from 3D displays to spintronics, as well as anticounterfeiting.

Design of a circularly polarized microstrip slot antenna using Minkowski fractal by the characteristic mode theory

In this paper, the Minkowski fractal is used for the design of a microstrip slot antenna by the characteristic mode theory, whereby the radiation mode generating the desired radiation patterns is excited. The right-hand circular polarization (RHCP) antenna is first designed and then the method of polarization reversal from RHCP to left-hand circular polarization is presented by the design of the feed system. The FR-4 substrate is used for the design of the slot antenna at 2.45 GHz. Also, the frequency spectrum of ISM includes that of WiFi, which has a single feed port. The use of Minkowski fractal has resulted in 0.28λ0 × 0.28λ0 miniaturization of the slot antenna. For the proof of concept, a prototype model of the proposed slot antenna is simulated, designed, fabricated and measured, which shows good agreement between the simulation results and measurement data.

Dual-Frequency Linear-to-Circular Polarization Converter for Ka-Band Applications.

A dual-band linear-to-circular planar polarization converter based on a multilayer printed circuit board (PCB) is proposed and demonstrated. Each cell of the periodic surface is formed by six substrate layers separated by five foam spacers. The three top layers are identical and contain an ‘I’-type strip, while the three layers on the bottom side are realized with three identical Jerusalem crosses (JC). A linearly polarized (LP) wave tilted 45° relative to the x- and y-axis of the converter is used to illuminate the polarizer. In this configuration, right-handed circularly polarized (RHCP) waves are generated at the Ka-band while left-handed circularly polarized (LHCP) waves are generated at the K-band. An equivalent circuit model based on transmission lines is proposed and used to design the polarizer together with full-wave simulations. The simulated/measured axial ratio (AR) remains below 3 dB in the bands 19.4–21.8 GHz (12.5%) and 27.9–30.5 GHz (8.7%) with an insertion loss better than 0.5 dB.

Lightweight switchable bifunctional metasurface based on VO2: High-efficiency absorption and ultra-wideband circular polarization conversion

Switchable multi-function metasurfaces have received much attention due to their excellent performance of manipulating electromagnetic waves. In this paper, we present a novel design that can realize a high-efficiency absorber and an ultra-wideband circular polarization converter based on an anisotropic metasurface through the phase transition of vanadium dioxide (VO2). At room temperature, the metasurface acts an ultra-wideband circular polarization converter with the VO2 film maintains an insulating state, the theoretical analysis and numerical simulation show that the polarization conversion ratio reaches more than 90% in an ultra-wide band (6.3–15.0 THz) and even reaches almost 100% at two peaks, the relative bandwidth is 82%. When the temperature increases to 68 ℃, the metasurface becomes a high-efficiency absorber with VO2 film in metallic state. Numerical calculations show that the absorber has over 90% high-efficiency absorption of X-linearly polarized wave in the 10.8–13.2 THz frequency range and over 90% high-efficiency absorption of left-handed circular polarization wave in the 10.8–14.4 THz frequency range, both are angle insensitivity for small incident angles from 0° to 20°. The physical mechanisms of the two functions based on our structure are discussed. Our novel design has potential significance in future terahertz medical imaging, non-destructive detectors, polarization converters, and THz communication system.

Wideband Dual-Circular-Polarization Antenna With High Isolation for Millimeter-Wave Wireless Communications

This article presents a wideband dual-circular-polarization (dual-CP) antenna with high port isolation based on a grooved-wall CP horn combined with an orthomode transducer (OMT) in the W-band. A pair of grooves on the inner wall of the horn serves as an inbuilt polarizer within the horn antenna, which is capable of generating both left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) without any septum. The continuous linearly tapered groove design also allows this multisection grooved-wall CP horn to achieve low reflection coefficients over a wide bandwidth, thereby realizing wideband dual-CP with high port isolation when it is used together with a wideband OMT. A prototype of the proposed dual-CP antenna is designed in simulation and measured in an experiment. The simulated and measured results agree very well, showing that port isolation >32.5 dB over 31.6% bandwidth from 80 to 110 GHz is achieved with axial ratio (AR) < 2.8 dB and reflection coefficient <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&lt; -20$ </tex-math></inline-formula> dB for both LHCP and RHCP. Rotationally symmetric radiation patterns over the entire operating bandwidth are also observed with a measured gain of 19.6 ± 2 dBic.

Circularly Polarized Leaky-Wave Antenna With Natural Curl Property

This letter proposes a novel leaky-wave antenna (LWA) based on low profile substrate integrated waveguide (SIW), which can operate in either left-handed circular-polarization (LHCP) or right-handed circular-polarization (RHCP) mode. Different from other kinds of literature, the proposed SIW LWA is capable of CP state switching without introducing multiple LWA elements, phase-correct couplers or polarization converter, which is a single LWA element with a simple coaxial feeding/matching structure. Specially, the periodic slots on its radiation aperture are Archimedean spiral slots which are curved slots with curl property. These curled slots can excite vortex fields in the waveguide channel of SIW, and the generated vortex field is capable of changing vortex direction by selectively exciting the port of LWA, making the CP features flexible. The final Archimedean spiral slotted SIW LWA realizes LHCP or RHCP (AR < 3 dB) in the wide CP band of 27.7–34.6 GHz (BW = 22%), and the LHCP scanning range is from −51° to −10° while the RHCP beam scans from 10° to 50°.

Tailoring standing waves on meta-atom: a facile way to a high-efficiency functional metasurface with spin-selectivity

Metasurfaces have provided unprecedented degrees of freedom in manipulating electromagnetic (EM) waves and have been applied in the communication field. Growing communication demands require smaller and more versatile devices. However, there is still a gap in recent miniaturization versatile research. Here, we propose a design method to realize an ultrathin multifunctional metasurface by tailoring standing waves that formed on meta-atom both in longitudinal and transverse dimensions. Firstly, to guarantee high-efficiency coupling between incident waves and meta-atom, we place the metallic pattern at the peak point of longitudinal standing waves which formed by the interferences between incident and reflected waves via adjusting the substrate thickness. Then we can realize the diverse functions for different incident spin states by loading lumped elements at the standing wave peaks or nodes of the transverse surface currents. For this proof-of-concept, we demonstrate a spin-selective vortex beam generation metasurface with an ultrathin thickness 0.144λ0. The design can generate a vortex beam for right-handed circularly polarized (RHCP) waves with an efficiency above 80% in 14.0-23.0 GHz while it can achieve high absorption above 90% for left-handed circularly polarized (LHCP) waves in 13.8-23.3 GHz. To sum up, this method might help to design spin-selective metasurfaces with multifunctional integration and find applications in satellite communication, EM compatibility and others.

Polarization-Insensitive Metalens and Its Applications to Reflectarrays With Polarization Diversity

A synthesized strategy for achieving polarization-insensitive metalens is proposed by imposing identical parabolic phase patterns individually on two decoupled left-handed (spin up, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sigma +$ </tex-math></inline-formula> ) and right-handed (spin down, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sigma -$ </tex-math></inline-formula> ) circular polarization (CP) channels of an anisotropic scheme. This is enabled by synergizing dynamic phases and local geometric phases within 0° and 90° rotations. As a consequence, similar focusing behavior is expected when it is illuminated by a plane wave of arbitrary polarization since any incoming wave is a superposition of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sigma +$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sigma -$ </tex-math></inline-formula> wave. Such an intriguing feature can be utilized to engineer a polarization-insensitive reflectarray/transmitarray in a shared aperture by placing a feeding source of different polarizations at its focal spot without altering the array aperture. Therein, the polarization of the meta-array is determined by its feeding which is readily to be changed in practice. For demonstration and possible applications, two reflectarrays composed of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50\times50$ </tex-math></inline-formula> elements at Ku band with one in normal and the other in offset configuration were designed and experimentally characterized. Numerical and experimental results illustrate that both reflectarrays are able to work in Dual linear polarization (LP) and Dual CP states by utilizing LP and CP horns of different orientations. Moreover, the versatile polarization-agile property does not pose a significant penalty on its radiation performance and both reflectarrays exhibit a measured peak aperture efficiency of 63.8% and 39.6%, respectively, near 14 GHz, and a 1 dB gain bandwidth more than 11.8%.

Harmonic Suppression and Size Reduction of a Low-Profile CP Patch Antenna by Using Nondegenerate Modes

A novel design method of harmonic suppression and size reduction of a circularly polarized (CP) microstrip patch antenna (MPA) is presented by using nondegenerate modes. Based on a circular MPA, a pair of orthogonal modes could be generated between these undesired resonant modes. Then, by loading the shorting pins in a quarter fan-shaped patch, all these undesirable high-order modes could be suppressed between them. After that, the higher and lower modes are moved closer to each other by cutting a long slot at the angle bisector of the fan-shaped patch, providing the CP radiation pattern. Finally, a prototype of this proposed antenna has been designed, produced, and measured to verify the design concept. The experimental results show that the proposed antenna has an impedance bandwidth of 286 MHz (13 774–14 060 MHz), axial ratio bandwidth of 80 MHz (13 900–13 980 MHz), and a left-hand CP peak gain of around 4.8 dBi. Most importantly, the CP antenna has realized the harmonic suppression of about 15 GHz, which has an obvious advantage as compared to the traditional CP MPA. Moreover, the antenna still holds the primary low-profile, single-radiator, simple structure, and high-efficiency simultaneously.

Dual-Wavelength Polarization-Dependent Bifocal Metalens for Achromatic Optical Imaging Based on Holographic Principle.

Recently, ultrathin metalenses have attracted dramatically growing interest in optical imaging systems due to the flexible control of light at the nanoscale. In this paper, we propose a dual-wavelength achromatic metalens that will generate one or two foci according to the polarization of the incident. Based on geometric phase modulation, two unit cells are attentively selected for efficient operation at distinct wavelengths. By patterning them to two divided sections of the metalens structure plane, the dual-wavelength achromatic focusing effect with the same focal length is realized. In addition, the holographic concept is adopted for polarization-dependent bifocal generation, in which the objective wave is originated from two foci that are respectively formed by two orthogonal polarization states of circularly polarized light, namely Left-handed circularly polarized (LCP) light and Right-handed circularly polarized (RCP) light. The incident light is considered as the reference light. The achromatic focusing and polarization-dependent bifocusing are numerically verified through simulations. The proposed design opens the path for the combination of multi-wavelength imaging and chiral imaging, which may find potential applications, such as achromatic optical devices and polarization-controlled biomedical molecular imaging systems.

A low-profile broadband circularly polarized metasurface antenna based on characteristic mode analysis

A new broadband circularly polarized (CP) metasurface (MS) antenna based on characteristic mode analysis (CMA) is proposed. The antenna consists of 4×4 truncated Γ-shaped unit cells and is fed by an improved slot coupling structure. The characteristic modes required to achieve CP are analyzed by CMA, and the CP performance is improved by changing the characteristic currents distribution. By introducing a stepped slot structure on the slot floor, the bandwidth of the antenna has been further broadened. By loading the microstrip line to feed the MS, left-handed circular polarization (LHCP) can be realized. In addition, the equivalent circuit method is used to explain how the designed MS antenna achieves CP. The overall size of the designed and fabricated MS antenna is 0.72×0.72×0.08 at 6.2 GHz. The measured −10 dB impedance bandwidth of the antenna is 25.17% (5.21 GHz-6.71 GHz) and the measured 3 dB axial ratio bandwidth is 17.42% (5.87 GHz-6.99 GHz). Moreover, the highest gain in the working frequency band is 7.52 dBic. The proposed CP MS antenna has good application prospects in C-band satellite communications.

Generation and conversion of a dual-band Laguerre-Gaussian beam with different OAM based on a bilayer metasurface

In this paper, we propose a bilayer metasurface with dual-operating modes to realize the generation and conversion of dual-band Laguerre-Gaussian beam with different OAM. The bilayer metasurface consists of amorphous silicon (a-Si) and amorphous antimony selenide (a-Sb2Se3). In transmission mode, the metasurface can transform incident left-handed circularly polarized (LCP) Gaussian beam into one LCP Laguerre-Gaussian beam carrying topological charge l=−2 and one right-handed circularly polarized (RCP) Laguerre-Gaussian beam carrying topological charge l=−1, which enabled OAM modes multiplexing. In reflection mode, the metasurface can convert an incident LCP Gaussian beam into a LCP Laguerre-Gaussian beam carrying a topological charge l=−3 owing to the a-Sb2Se3 nanopillar that acts as a half-wave plate with high reflectivity. In addition, the OAM conversion between two arbitrary modes can be realized by the proposed metasurface. This work provides a valid method for OAM multiplexing and conversion, which holds a great applications value in high-speed optical communication systems.

A Low-Profile Broadband Metasurface Antenna With Polarization Conversion Based on Characteristic Mode Analysis

In this paper, a low-profile, broadband metasurface antenna for polarization conversion is proposed based on characteristic mode analysis (CMA). A new type of metasurface unit with a partially chamfered symmetrical triangular structure is designed. The inherent physical characteristics of the antenna are analyzed based on CMA, and the expected characteristic modes are selected for excitation at a suitable position. Slot-coupled feeding via microstrip line realizes the performance of wide impedance bandwidth and axial ratio bandwidth (ARBW). The measured -10 dB impedance bandwidth of 36.3% (4.38–6.32 GHz) and the 3 dB ARBW of 20.1% (5.41–6.62 GHz) are achieved. The left-hand circular polarization (LHCP) is realized, and the measured highest gain in the working frequency band is 6.05 dBic. The overall size of the designed and fabricated metasurface antenna is 0.58 λ0 × 0.58 λ0 × 0.07 λ0at 5 GHz. The proposed metasurface antenna can be well used in C-band satellite communications due to its low profile, broadband, and circular polarization.

Generating diverse functionalities simultaneously and independently for arbitrary linear polarized illumination enabled by a chiral transmission-reflection-selective bifunctional metasurface.

A multifunctional metasurface is capable of manipulating electromagnetic waves and achieving kaleidoscopic functions flexibly, which significantly improves the integration and utilization of a single metasurface and has become one of the hotspots in electromagnetics. However, the majority of designs to date can only operate for limited polarization states in half-space and are difficult to show diverse functions at the same time, which restrict the widespread applications of multifunctional metadevices. Herein, an inspiring strategy of a chiral transmission-reflection-selective bifunctional metasurface is proposed to generate two independent functions in co-polarized reflection channel for left-handed circular polarized (LCP) incidence utilizing rotation-induced geometric phase modulation and in co-polarized transmission channel for right-handed circular polarized (RCP) incidence utilizing scaling-induced propagation phase modulation, and both functions appear concurrently under arbitrary linear polarized (LP) incident waves. To verify the feasibility of this methodology, three proof-of-concept metadevices composed of a dual-mode orbital angular momentum (OAM) generator, a bifocal metalens and an integrated metadevice of OAM generator and metalens are constructed and their performances in simulations and experiments are in good accordance with the theoretical ones. This exotic design of bifunctional metasurface will open up a promising way for multifunctional metadevices in engineering applications.