Phase-tuning Metasurface for Circularly Polarized Broadside Radiation in Broadband

Abstract

Metasurface antennas (MAs) have been proposed as innovative alternatives to conventional bulky configurations for satellite applications because of their low profile, low cost, and high gain. The general method of surface impedance modulation for designing MAs is complicated, and achieving broad operation bandwidth remains a challenge because of its high dispersion response. We propose a novel and easy technique to control cylindrical surface waves radiated by a phase-tuning metasurface. Simultaneously, this technique exhibits a considerably wide working bandwidth. A detailed analysis of the radiation mechanism is discussed. A left-hand circularly polarized (LHCP) antenna and a right-hand circularly polarized (RHCP) antenna that are based on the phase-tuning metasurface are simulated and measured. The measured fractional 3-dB gain bandwidth and gain are higher than 17% and 15.57 dBi, respectively, which are consistent with the simulated results. Moreover, 30% 3-dB axial ratio is achieved for the LHCP and RHCP antennas. To the best knowledge of the authors, it is for the first time to realize a circularly polarized broadband MA by using the phase-tuning mechanism. The approach can be regarded as a new starting point for antenna design, thereby paving the way for the development of broadband and low-profile antennas for future satellite communication.

On geometry parameterization for simulation-driven design closure of antenna structures

“…This can be mainly attributed to the emergence of new technologies (4G and 5G wireless communications 6 , medical imaging 7 , wireless sensing 8 , implantable devices 9 ), but also trends towards miniaturization and portability (mobile communications 10 , internet of things, IoT 11 , wearable devices 12 ). On the one hand, to fulfil the performance requirements imposed by the needs pertinent to specific application areas, antenna structures have to implement additional functionalities (multi-band operation 13 , tunability 14 , circular polarization 15 ), but also offer improved characteristics (high gain 16 , broadband operation 17 , high element isolation in MIMO systems 18 , etc.). This requires incorporation of a variety of geometrical alterations (stubs 19 , slots 20 , defected ground structures 21 , metamaterial-based components 22 ), which makes the designs increasingly sophisticated and described by large numbers of parameters.…”

Performance Enhancement of Array Antennas using Metasurface Superstrates

“…The sun emits electromagnetic radiation with a continuous spectrum range, which extends from ultra-violet (5%) to infra-red (55%) via the visible region (40%). The infrared (IR) band extends from 300 GHz to 430 GHz with three sub-bands namely far, mid, and near IR 3 . The near IR range is the most important range for energy harvesting because its radiation reaches the surface of the earth.…”

“…This radiation is absorbed by the surface of the earth and then re-radiated in spectral range of 7-17μm with a maximum peak of power at 10.6 μm (28.3 THz) 4 . Modern day mobile, radar, space and wireless communication applications demand circularly polarized (CP) beam-steering antennas that have the characteristics of high gain, wide band impedance matching bandwidth as well as excellent axial ratio bandwidth [1][2][3][4] . High-gain antennas are [Correction added on 27 January 2020, after first online publication: the affiliation 'United Arab Emirates' has been added to Dr. Yousaf in this version.]…”

“…Recently, a number of different structures to enhance the gain of the smart antennas along with steering of their radiation patterns have been proposed. These include: electromagnetic bandgap (EBG) surfaces 9 , butler matrix 10 frequency selective surfaces (FSSs) 1,11,12 , reactive impedance surface (RIS) 13,14 , partially reflecting surfaces (PRSs) 4,15 , artificial magnetic conductors (AMCs) 16 , dielectric layers 3,4,[17][18][19] and Metasurface (MTS) as superstrate 3,5,17,[20][21][22][23][24][25][26][27] . Metasurface based antennas have emerged as proposed alternatives to the traditional bulky antenna configurations because of their low fabrication cost, low profile, wide operational impedance bandwidth and gain 3,5,26 .…”

“…These include: electromagnetic bandgap (EBG) surfaces 9 , butler matrix 10 frequency selective surfaces (FSSs) 1,11,12 , reactive impedance surface (RIS) 13,14 , partially reflecting surfaces (PRSs) 4,15 , artificial magnetic conductors (AMCs) 16 , dielectric layers 3,4,[17][18][19] and Metasurface (MTS) as superstrate 3,5,17,[20][21][22][23][24][25][26][27] . Metasurface based antennas have emerged as proposed alternatives to the traditional bulky antenna configurations because of their low fabrication cost, low profile, wide operational impedance bandwidth and gain 3,5,26 . Metasurfaces, act as local gradient phase shifters of the incident electromagnetic waves (EM), and serve to modify the wavefronts of the incident EM waves 3,13,24,27,28 .…”