Conference PaperPDF Available

Multibeam Antenna Implementation Using Anisotropic Metasurfaces

June 2022

DOI:10.1109/EDM55285.2022.9855123

Conference: 2022 IEEE 23rd International Conference of Young Professionals in Electron Devices and Materials (EDM)

Authors:

Anton Chesnitskiy

Institute of Semiconductor Physics, Russian Academy of Sciences

Pavel Sibirtsev

ITMO University

Show all 6 authorsHide

Application of 3-beam metasurface antenna (MSA) for LEO satellite communications.

…

Figures - uploaded by Anton Chesnitskiy

Content may be subject to copyright.

Content uploaded by Anton Chesnitskiy

Content may be subject to copyright.

2022 IEEE 23rd INTERNATIONAL CONFERENCE OF YOUNG PROFESSIONALS IN ELECTRON DEVICES AND MATERIALS (EDM)

Multibeam Antenna Implementation Using

Anisotropic Metasurfaces

Anton V. Chesnitskiy

Laboratory of Nanotechnologies and

Nanomaterials

Rzhanov Institute of Semiconductor

Physics, Siberian Branch of the

Russian Academy of Sciences

Novosibirsk, Russia

achesnitskiy@gmail.com

Aleksey N. Kosmynin

dept. of Research and Development

«Matrix Wave» LLC

Moscow, Russia

alekseykosmynin@matrixwave.tech

Oleg M. Kaigorodov

dept. of Research and Development

«Matrix Wave» LLC

Moscow, Russia

olegkaigorodov@matrixwave.tech

Pavel A. Sibirtsev

Higher School of Applied Physics and

Space Technologies

Peter the Great St.Petersburg

Polytechnic University

St.Petersburg, Russia

sibirtsev.pa@edu.spbstu.ru

Ksenia N. Kosmynina

dept. of Information Systems and

Technology

Skolkovo Institute of Science and

Technology

Moscow, Russia

ksenia.kosmynina@skoltech.ru

Konstantin V. Lemberg

Scientific Instrumentation Laboratory

Kirensky Institute of Physics, Siberian

Branch of the Russian Academy of

Sciences

Krasnoyarsk, Russia

lemkon@inbox.ru

Abstract—This study is devoted to the development and

research of multibeam antennas based on anisotropic

metasurfaces with one or several feed points. An innovative

technique for synthesizing the tensor impedance distribution for

the formation of three beams from a radiating metasurface was

proposed. Prototypes of the proposed antennas in the Ku-band

frequency with one and three feed points were fabricated, and

their characteristics were experimentally investigated. The gain

of the manufactured multibeam antennas reaches 23 dBi. Good

agreement between the results of the numerical simulation and

experimental data was achieved, which indicates the

reproducibility of the synthesis method in practice. Multibeam

antennas on anisotropic metasurfaces can be scaled to high

frequencies and effectively used at operating frequencies up to

the sub-terahertz range. Such antennas are promising for the

development of terrestrial communication infrastructure as

5/6G transmitters and repeaters, as well as for use as a payload

of low-orbit satellite systems.

Keywords—metasurface antennas, multibeam, beamforming,

5/6G Networks, LEO satellite, MIMO

I. INTRODUCTION

In recent years, 5/6 generation networks have rapidly

developed, and it has become necessary to transmit a signal

over one or more channels and redirect it in the necessary

directions [1]. When designing the infrastructure of multiple

access networks operating at higher frequencies, one of the

tasks is the effective redistribution of the signal using

multipath repeaters [2, 3]. Thus, for the implementation of

high-level technologies such as ultra-dense networks,

massive multiple inputs and multiple outputs (MIMO), and

full duplex, the development of multipath antennas is a

challenge [4, 5]. In addition, the relevance of these antennas

is dictated by the emergence of software-defined low-orbit

(LEO) satellite and high-altitude pseudo-satellite (HAPS)

communication systems and the creation of coverage areas

with high-speed Internet access on Earth's territories (Fig. 1)

[6]. Metasurfaces are known to effectively solve the problem

of controlling the amplitude, phase, and polarization of

radiation in the optical, microwave, and terahertz ranges [7-

10].

Antennas based on tensor metasurfaces are a promising

tool for beamforming [11, 12]. By setting the parameters of

the modulation of the impedance tensor over the surface, it is

possible to obtain the desired radiation patterns of antennas,

including those with oblique [13] and flattened beams [14].

The classical methods for forming several beams using Butler

matrices [15] and Luneberg lenses [16] have a number of

disadvantages (manufacturing complexity and high cost) that

limit their wide application. The key advantages of a

metasurface antenna (MSA) are its low weight and

dimensions, simple design, and low cost of mass production.

Fig. 1 Application of 3-beam metasurface antenna (MSA) for LEO satellite

communications.

The numerical simulation was supported by the Ministry of Science

and Higher Education of the Russian Federation.

The experimental research was carried out with the financial support of

the RFBR, the Government of the Krasnoyarsk Territory and the

Krasnoyarsk Regional Science Foundation within the framework of the

scientific project 20–47–243002.

251

Authorized licensed use limited to: Skolkovo Institute of Science & Technology. Downloaded on September 03,2022 at 18:33:05 UTC from IEEE Xplore. Restrictions apply.

2022 IEEE 23nd INTERNATIONAL CONFERENCE OF YOUNG PROFESSIONALS IN ELECTRON DEVICES AND MATERIALS (EDM)

Planar MSA is more wind resistant compared to other

types of surround antennas and can also be easily integrated

into the body of small aircraft, drones, and microsatellites as

part of low-orbit constellations of satellite communications

[17].

This study proposes and implements a method for

synthesizing multibeam antennas based on anisotropic tensor

metasurfaces. Previously, it was shown [18] that anisotropic

metasurfaces are more flexible tools for beamforming and

have lower cross-polarization values than isotropic ones.

Prototypes of the proposed three-beam MSA with single

and three feed points were fabricated, and their characteristics

were investigated. The experimental results were in agreement

with the results obtained using the numerical FEM simulation.

The proposed multibeam MSAs are promising candidates for

building next-generation communication systems both on

Earth and in space.

II. METHODS

A. Synthesis of Anisotropic Metasurface

The electromagnetic properties of a two-dimensional

waveguide structure in the absence of heat losses are described

by the surface impedance tensor:

. (1)

If impedance modulation is introduced, the propagating

surface wave (SW) transforms into a leaky wave (LW), and

the structure radiates. Due to the fact that the previously

described impedance tensor is diagonal for mutual media,

only two components and given in polar

coordinates, determine the properties of the radiating surface.

Consider the distribution law of the surface impedance

component :

, (2)

where ρ is the radial coordinate of the point in cylindrical

coordinates, are the electric field strengths of the

object and reference waves, respectively, are the average

values of the impedance component realized by the cells,

is the range of values of the corresponding impedance

component.

In this study, the synthesis of antennas is based on the

calculation of the impedances of unit cells and the formation

of the target distribution of the impedance over the surface on

their basis [19]. An elliptical metal patch placed on the surface

of a 2 mm thick dielectric substrate with permittivity ε was

chosen as the unit cell of the anisotropic MSA (Fig. 2). A thin

metal screen is located under the dielectric and covers the 2D

waveguide structure from below. During the synthesis, the

geometric parameters of the anisotropic structure were varied,

such as the major and minor semi-axes of the ellipses a and b

and the angle of its rotation around the Z-axis. As a result, a

data array corresponding to a variety of elementary cell

impedances was formed. Subsequently, the target distribution

of the impedance over the surface was set according to (2) to

transform a cylindrical TM wave into a wave with the required

characteristics in free space.

Fig. 2 Geometry of anisotropic unit cell with dimensions 0.12λ0×0.12λ0.

By setting the modulation period of the impedance, the

direction of radiation, its polarization, and even the shape of

the beam can be changed. The impedance distributions

synthesized by this novel method for right-handed circular

polarization (RHCP) three-beam antennas with single and

three separate feed points are shown in Fig. 3. Based on the

distributions of impedances and impedances of individual

cells calculated at the previous stages, an aperture of a

multibeam metasurface antenna was formed.

Fig. 3 Variations of the Zρρ component impedance tensor for 3-beam MSA

(a) with single feed point in the center of the canvas; (b) with three separate

feed points.

uu uv

vu vv

éù

=êú

ëû

( ) ( )

obj ref

ref

ZZ Re

rr rr

æö

ç÷

=+ ×

ç÷

èø

( ) ( )

,refobj

ΔZ

252

Authorized licensed use limited to: Skolkovo Institute of Science & Technology. Downloaded on September 03,2022 at 18:33:05 UTC from IEEE Xplore. Restrictions apply.

2022 IEEE 23nd INTERNATIONAL CONFERENCE OF YOUNG PROFESSIONALS IN ELECTRON DEVICES AND MATERIALS (EDM)

Fig. 4 Simulated 3D far-field radiation patterns of 3-beam MSA at 12 GHz (a) with single feed point. With three separate power points: (b) with feeding of the

first point; (c) with feeding of the second point; (d) with the power supply of the third point.

B. Numerical Simulation

A numerical simulation of the radiation patterns of the

synthesized multibeam antennas and their characteristics was

performed using the finite element method (FEM). The

parameters of the synthesized anisotropic MSA are included

in the model. Because the quality of the selected dielectric has

a key effect on the antenna characteristics, the real parameters

of the FR4 dielectric with losses (

) were used to calculate the radiation

patterns.

The simulation results obtained for the radiation patterns

of the proposed multibeam anisotropic metasurfaces are

shown in Fig. 4. Fig. 4a show the 3D far-field radiation pattern

of a three-beam antenna with a single feed point. The color

map shows three distinct pencil-shaped beams with a gain of

about 23 dBi. Thus, a wave was simultaneously excited from

one canvas of the MSA in three directions. The tilt angle for

all beams was ïθï ~ 30°, and the main angles φ were 60°, 180°

and 300°. Fig. 4b-d shows the results for a three-beam antenna

with three separate feed points, when each feed point was fed

in turn. It can be observed that, when fed on from each point,

only one beam is excited in the desired direction. Thus, three

independent beams that are emitted simultaneously or

sequentially in free space can be obtained from one canvas.

This approach is promising for building networks with the

MIMO architecture using a single multibeam antenna and for

increasing the channel throughput and signal-to-noise ratio [5,

20-22].

III. EXPERIMENTAL RESULTS

The practical implementation of the proposed method for

the synthesis of multibeam antennas based on anisotropic

impedance metasurfaces and its experimental confirmation

were performed in the Ku-band. The two prototypes of the

developed three-beam MSAs were manufactured using

standard printed circuit board (PCB) technology on a widely

available inexpensive dielectric FR4. The aperture of the

antennas had the shape of an octahedron with dimensions of

380 mm×380 mm. To excite a surface wave of the TM type,

feeders in the form of a rod with a disk were used, and SMA

connectors were used to connect the feeders. Photographs of

the manufactured prototypes with connected feeders are

shown in Fig. 5. The directivity characteristics of the

fabricated three-beam antennas were measured in an anechoic

chamber using a near-field scanning method.

The results obtained from the experimental investigation

are compared with the numerical simulation results, which are

represented by red lines in Fig. 6. In this study, narrow-band

sinusoidal signals were used for excitation antenna during

simulation and measurements. In order to avoid overlapping

graphs and improve the perception of results, the cross section

for beam №2 is given at -180°. Fig. 6a shows the cuts of the

radiation patterns of the manufactured three-beam MSA with

a single feed point at main angles φ equal to 60°, -180° and

300°. The graph shows three peaks corresponding to beams

excited simultaneously from one aperture at a single feed

point.

4.5, 0.022

253

Authorized licensed use limited to: Skolkovo Institute of Science & Technology. Downloaded on September 03,2022 at 18:33:05 UTC from IEEE Xplore. Restrictions apply.

2022 IEEE 23nd INTERNATIONAL CONFERENCE OF YOUNG PROFESSIONALS IN ELECTRON DEVICES AND MATERIALS (EDM)

Fig. 5 Fabricated Ku-band antenna prototypes implemented on anisotropic elements with single (a) and three (b) feed points in an anechoic chamber. The numbers

indicate the feeder numbers.

In Fig. 6b-d the cuts in the radiation pattern of the

manufactured three-beam MSA with three separate feed

points are shown. It can be seen from the graphs that when

one feeder is fed on, only one beam is formed from the

aperture at a present time. With a corresponding change in the

feed point, another beam is excited in the required direction.

Table I lists the results of the measurements for all beam

directions of the manufactured three-beam antennas based on

anisotropic metasurfaces. The gain for all beam directions of

Prototypes №1 and №2 reaches 23 dBi with a parameter

spread of less than 5%. The angular width at the level -3 dB

for all beams was approximately 5°. From the graphs

presented in Fig. 6, it can be seen that good agreement was

achieved with the results of the FEM simulation, which are

shown by red lines in all graphs. The developed synthesis

method based on anisotropic metasurfaces enables the

synthesis of planar antennas with an arbitrary radiation

pattern shape and the required beam tilt angles. Further

improvement of the proposed technique and the use of

modern materials with lower losses will increase the aperture

efficiency and gain of the antennas.

Fig. 6. The cuts of simulated and measured far-field radiation patterns of developed three-beam MSAs at a central frequency of 12 GHz: (a) with single feed

point at φ equal to 60°, -180°, 300°. With separate feed points (b) when feed point №1 is excited at φ = 60°; (c) when the feed point №2 is excited at φ = -180°;

(d) when the feed point №3 is excited at φ = 300°.

Prototype №1

Prototype №2

254

Authorized licensed use limited to: Skolkovo Institute of Science & Technology. Downloaded on September 03,2022 at 18:33:05 UTC from IEEE Xplore. Restrictions apply.

TABLE I. FABRICATED MULTIBEAM MSA PERFORMANCE

Characteristics

Prototype №1

(Single feed point)

Prototype №2

(Three separate feed

points)

Central frequency

12 GHz

Dimensions

380×380 mm

Polarization

RHCP

Main beam φ

angle

60°

180°

300°

60°

180°

300°

Main beam θ

angle

29°

31°

30°

31°

Gain, dBi

24.3

23.6

24.2

23.6

23.0

24.1

Angular width at

level -3dB

4.8°

5.3°

5.1°

4.3°

IV. CONCLUSION

This study proposes and implements a method for

forming multibeam antennas based on anisotropic

impedance metasurfaces. Using the proposed approach,

prototypes of planar low-cost three-beam Ku-band

antennas with single or three separate feed points were

fabricated. The gain of the MSAs reaches 23 dBi and

aperture efficiency was approximately 40%. The results of

the experimental measurements agreed well with the

results of the numerical FEM simulation. The proposed

antennas based on impedance metasurfaces are a

promising element base for building terrestrial networks

of 5/6 generations and implementing LEO satellite,

pseudo-satellite HAPS, and unmanned aerial vehicle

(UAV) communication systems.

REFERENCES

[1] W. Hong, Z. H. Jiang, C. Yu, J. Zhou, P. Chen, Z. Yu, H. Zhang, B.

Yang, X. Pang, M. Jiang, Y. Cheng, M. K. Taher Al-Nuaimi, Y. Zhang,

J. Chen, and S. He, “Multibeam antenna technologies for 5G wireless

communications,” IEEE Transactions on Antennas and Propagation,

vol.68, no. 12, pp. 6231-6249, 2017.

[2] E. W. Matthews, W. G. Scott, and C. C. Han, “Multibeam antennas for

data communications satellites,” in Proceedings of the fifth symposium

on Data communications, pp. 2-20, 1977.

[3] W. Li, T. Qiu, J. Wang, L. Zheng, Y. Jing, Y. Jia, W. He, Y. Han, and

S. Qu, “Programmable coding metasurface reflector for reconfigurable

multibeam antenna application,” IEEE Transactions on Antennas and

Propagation, vol.69 no. 1, pp. 296-301, 2020.

[4] F. Zhu, T. Ba, Y. Zhang, X. Gao, S. Zhai, and X. Gong, “Low

complexity detection method based on channel matrix periodic N-

diagonal equivalence for uplink MU-MIMO of multibeam satellite

communication systems,” International Journal of Satellite

Communications and Networking, vol. 39, no. 5, pp. 509-523, 2021.

[5] Y. Hu, J. Zhan, Z. H. Jiang, C. Yu, and W. Hong, “An orthogonal

hybrid analog–digital multibeam antenna array for millimeter-wave

massive MIMO systems,” IEEE Transactions on Antennas and

Propagation, vol. 69, no. 3, pp. 1393-1403, 2020.

[6] M. Á. Vázquez, A. Perez-Neira, D. Christopoulos, S. Chatzinotas, B.

Ottersten, P. D. Arapoglou, A. Ginesi, and G. Taricco, “Precoding in

multibeam satellite communications: Present and future challenges,”

IEEE Wireless Communications, vol. 23 no. 6, pp. 88-95, 2016.

[7] H. T. Chen, A. J. Taylor, and N. Yu, “A review of metasurfaces:

physics and applications,” Reports on progress in physics, vol. 79 no.

7, 2016.

[8] F. Ding, A. Pors, and S. I. Bozhevolnyi, “Gradient metasurfaces: a

review of fundamentals and applications,” Reports on Progress in

Physics, vol. 81, no.2, 2017.

[9] V. Y. Prinz, E. V. Naumova, S. V. Golod, V. A. Seleznev, A. A.

Bocharov, and V. V. Kubarev, “Terahertz metamaterials and systems

based on rolled-up 3D elements: designs, technological approaches,

and properties,” Scientific reports, vol. 7, no. 1, pp. 1-15, 2017.

[10] S. V. Golod, V. A. Seyfi, A. F. Buldygin, A. E. Gayduk, and V. Y.

Prinz, “Large Area 3D-Printed Chiral Metasurface Composed of Metal

Helices,” Advanced Optical Materials, vol. 6, no. 19, 2018.

[11] J. Hu, S. Bandyopadhyay, Y. H. Liu, and L. Y. Shao, “A review on

metasurface: from principle to smart metadevices,” Frontiers in

Physics, no. 8, p. 502, 2021.

[12] M. Faenzi, G. Minatti, D. González-Ovejero, F. Caminita, E. Martini,

C. Della Giovampaola, and S. Maci, “Metasurface antennas: New

models, applications and realizations,” Scientific reports, vol. 9, no.1,

pp. 1-14, 2019.

[13] D. Gonsalez-Ovejero, G. Minatti, G. Chattopadhyay, and S. Maci,

“Multibeam by metasurface antennas,” IEEE Transactions on

Antennas and Propagation, vol. 65, no. 6, pp. 2923-2930, 2017.

[14] M. Bodehou, E. Martini, S. Maci, I. Huinen, and C. Craeye,

“Multibeam and beam scanning with modulated metasurfaces,” IEEE

Transactions on Antennas and Propagation, vol. 68, no. 3, pp. 1273-

1281, 2019.

[15] J. Butler, “Beam-forming matrix simplifies design of electronically

scanned antennas,” Electronic design, vol. 12, pp. 170–173, 1961.

[16] R. K. Luneburg, “The Mathematical Theory of Optics,” Providence,

RI: Brown Univ, in press, 1944.

[17] K. Y. Zhong, Y. J. Cheng, H. N. Yang, and B. Zheng, “LEO Satellite

Multibeam Coverage Area Division and Beamforming Method,” IEEE

Antennas and Wireless Propagation Letters, vol. 20 no. 11, pp. 2115-

2119, 2021.

[18] G. Minatti, M. Faenzi, E. Martini, F. Caminita, P. De Vita, D.

González-Ovejero, M. Sabbadini, and S. Maci, “Modulated

metasurface antennas for space: Synthesis, analysis and

realizations,” IEEE Trans. Antennas Propag., vol. 63, no. 4,

pp. 1288–1300, Apr. 2015.

[19] K. V. Lemberg, A. N. Kosmynin, A. M. Aleksandrin, E. O.

Grushevsky, and I. V. Podshivalov, “Method of Anisotropic

Metasurface Unit Cell Surface Impedance Calculation,” IEEE

Radiation and Scattering of Electromagnetic Waves, pp. 1273-1281,

2021.

[20] P. Harrop, M. Dyson, J. Edmondson, and R. Das, “6G communications

reconfigurable intelligent surface roadmap, material, market 2021-

2045”, 2021.

[21] G. K. Kurt, M. G. Khoshkholgh, S. Alfattani, A. Ibrahim, T. S. J.

Darwish, Md S. Alam, H. Yanikomeroglu, and A. Yongacoglu, “A

vision and framework for the high altitude platform station (HAPS)

networks of the future,” IEEE Communications Surveys & Tutorials,

vol. 23, no. 2, pp. 729-779, 2021.

[22] A. V. Chesnitskiy, E. A. Mikhantiev, “The detection limit of curved

InGaAs/AlGaAs/GaAs Hall bars,” Russian Microelectronics, vol. 45,

no. 2., pp. 105-111, 2016.

255

Authorized licensed use limited to: Skolkovo Institute of Science & Technology. Downloaded on September 03,2022 at 18:33:05 UTC from IEEE Xplore. Restrictions apply.

Multibeam Beamforming Technology in Microwave Power Transfer and Harvesting

Article

Full-text available

Jan 2025

The rise in popularity of the Internet of Things (IoT) has increased the need to power devices wirelessly, a process called Wireless Power Transfer (WPT), to avoid the usage of batteries, which present limited lifespans. In particular, Microwave Power Transfer (MPT), both Near-field (NF) and Far-field (FF), use Electromagnetic (EM) waves to transfer power between two points. However, these systems still present some downsides, mainly efficiency-wise. This paper explores the usage of Multibeam Antennas (MBAs), specifically Beamforming Network (BFN)-based ones, to improve the capabilities of traditional MPT and Radio Frequency Energy Harvesting (RFEH) systems. The paper starts by introducing the usage of MPT in IoT applications and how MBAs could help solve some of them or at least mitigate them. Afterward, a general explanation of the typical MBAs architectures, including Passive Multibeam Antennas (PMBAs), Multibeam Phased-Array Antennas (MBPAAs), and Digital Multibeam Antennas (DMBAs) is presented, along with their advantages, drawbacks, and some emerging trends. After introducing the typical architectures of MBAs, a comprehensive literature survey is done around rectennas and MPT Transmitters (TXs). This approach allows us to understand better why some architectures are more present than others in both applications, highlighting the exclusive usage of PMBAs in rectennas due to them not using energy. To finalize the paper, using the literature survey done, some challenges associated with integrating MBAs in MPT and RFEH are presented, along with some works presenting ways to mitigate them.

High efficiency holographic impedance metasurface for dual circular polarized OAM waves

Article

Full-text available

Feb 2024
MICROW OPT TECHN LET

This paper proposes a high aperture efficiency (AE) small size tensor holographic impedance metasurface (THIMS), which has the ability to create circular polarized (CP) high purity orbital angular momentum (OAM) multi‐beams with flexibly independent control of the individual beam direction, polarization and OAM mode. The tensor unit cell is a cross‐slotted circular patch. We design a THIMS at 14.6 GHz for dual CP OAM beams: Beam‐I (LHCP, l = 1, θ1 = 30°, φ1 = 0°), Beam‐II (RHCP, l = −1, θ2 = 30°, φ2 = 180°). The developed tensor dual CP THIMS has the following advantages: high purity in xoy plane at z = 9.73 λ (λ wavelength, measured purity 88.4% for Beam‐I, and 93.5% for Beam‐II), high AE 25.1%, and small size 5.986 λ × 5.986 λ × 0.0618 λ. The calculated, simulated and measured results agree well. The generated dual CP OAM beams have potential applications for high‐capacity wireless communication, radar high resolution imaging, and rotation velocity measurement.

Experimental Demonstration of A Dual-Input/Dual-Output Reflective Impedance Metasurface

Preprint

Feb 2023

This paper presents the experimental demonstration of a dual-input/dual-output reflective impedance metasurface. The design of the metasurface relies on the Method of Moments and leverages auxiliary surface waves to achieve anomalous reflection of impinging plane waves with controlled sidelobe levels. A prototype that ensures maximum directivity at prescribed angles for the reflection of the two input waves is then fabricated on a Rogers RO3003 printed-circuit board using 42 metawires loaded with printed capacitors. The proposed metasurface is capable of reflecting incident beams from

-20^\circ

0^\circ

and from

+20^\circ

-40^\circ

at 9.7 GHz. The metasurface is measured and an aperture efficiency of at least 80% is calculated for each of the reflected waves, indicating a high multiplexing efficacy.

Design of a multibeam metasurface antenna for LEO satellite communications payload

Article

Full-text available

Nov 2022

In this paper, we propose a novel method for synthesizing a multibeam metasurface antenna (MSA) for use in a space application - a payload component of a small satellite as part of a low Earth orbit (LEO) satellite communication constellation. MSA is synthesized using the holographic technique with a divergent phase distribution. Using this method, a low-cost multi-beam Ku-band antenna with seven flattened beams is developed. The results of the numerical simulation and experimental study of the proposed seven-beam MSA were presented. The gain of each beam is about 25 dBi, the aperture efficiency of the MSA is ~40%. Each individual beam had a separate feed point and its own inclination angle (0°, ±3.5°, ±7°, ±10.5°). This paper shows that the presented MSA is not inferior in its characteristics to similar solutions, but is more compact and lighter, and also allows the formation of complex radiation patterns.

Programmable Coding Metasurface Reflector for Reconfigurable Multibeam Antenna Application

Article

Full-text available

Jan 2021

In this paper, we propose a method of designing programmable coding metasurface with a reconfigurable number of reflected beams. Each unit cell of the metasurface is loaded with one varactor to enable adjustable phase responses. The bias, under beneath the ground drilled with small holes, is connected to unit cells by thin via through the holes, to avoid adverse influences on unit cells. To simplify the bias network, a super unit composed of 5×5 unit cells is taken as the coding element of realizing 2D coding sequences. With different bias voltages, the unit cell will produce different reflection phases. By programming the bias voltages, the number and directions of reflected beams can be tailored due to different coding sequences. Under normal incident, reflected waves will be split into multiple beams whose directions can be flexibly controlled. We designed a prototype, implemented our design and carried out experiments. Both simulation and experiment results show that the number of reflected beams can be reconfigured between 1 and 5. Reflect beam number reconfigurability of such metasurfaces can be readily used as planar reflector of antennas and may find applications in wireless communications.

Low‐complexity detection method based on channel matrix periodic N‐diagonal equivalence for uplink MU‐MIMO of multi‐beam satellite communication systems

Article

Full-text available

May 2021
INT J SATELL COMM N

In this paper, a low‐complexity detection method for uplink Multi‐User Multiple‐Input Multiple‐Output (MU‐MIMO) of multi‐beam satellite communication systems is studied. Firstly, we derive the uplink receiving system model and give the beam‐domain channel expression. Utilizing the characteristics of energy concentration of uplink channel in beam domain, we propose that the channel matrix can be equivalent to periodic N‐diagonal matrix, which can reduce the number of channel estimations and reduce the computational complexity of detection. Then, based on the beam‐domain channel matrix equivalent model, two low‐complexity minimum mean square error (MMSE) detection methods are proposed to reduce the computational complexity of traditional MMSE detection from OK2 to O(K). Simulation results show that the proposed methods have limited performance loss compared with the traditional methods.

A Vision and Framework for the High Altitude Platform Station (HAPS) Networks of the Future

Article

Full-text available

Mar 2021

A High Altitude Platform Station (HAPS) is a network node that operates in the stratosphere at an of altitude around 20 km and is instrumental for providing communication services. Precipitated by technological innovations in the areas of autonomous avionics, array antennas, solar panel efficiency levels, and battery energy densities, and fueled by flourishing industry ecosystems, the HAPS has emerged as an indispensable component of next-generations of wireless networks. In this article, we provide a vision and framework for the HAPS networks of the future supported by a comprehensive and state-of-the-art literature review. We highlight the unrealized potential of HAPS systems and elaborate on their unique ability to serve metropolitan areas. The latest advancements and promising technologies in the HAPS energy and payload systems are discussed. The integration of the emerging Reconfigurable Smart Surface (RSS) technology in the communications payload of HAPS systems for providing a cost-effective deployment is proposed. A detailed overview of the radio resource management in HAPS systems is presented along with synergistic physical layer techniques, including Faster-Than-Nyquist (FTN) signaling. Numerous aspects of handoff management in HAPS systems are described. The notable contributions of Artificial Intelligence (AI) in HAPS, including machine learning in the design, topology management, handoff, and resource allocation aspects are emphasized. The extensive overview of the literature we provide is crucial for substantiating our vision that depicts the expected deployment opportunities and challenges in the next 10 years (next-generation networks), as well as in the subsequent 10 years (next-next-generation networks).

A Review on Metasurface: From Principle to Smart Metadevices

Article

Full-text available

Jan 2021

Metamaterials are composed of periodic subwavelength metallic/dielectric structures that resonantly couple to the electric and magnetic fields of the incident electromagnetic waves, exhibiting unprecedented properties which are most typical within the context of the electromagnetic domain. However, the practical application of metamaterials is found challenging due to the high losses, strong dispersion associated with the resonant responses, and the difficulty in the fabrication of nanoscale 3D structures. The optical metasurface is termed as 2D metamaterials that inherent all of the properties of metamaterials and also provide a solution to the limitation of the conventional metamaterials. Over the past few years, metasurfaces; have been employed for the design and fabrication of optical elements and systems with abilities that surpass the performance of conventional diffractive optical elements. Metasurfaces can be fabricated using standard lithography and nanoimprinting methods, which is easier campared to the fabrication of the counterpart 3 days metamaterials. In this review article, the progress of the research on metasurfaces is illustrated. Concepts of anomalous reflection and refraction, applications of metasurfaces with the Pancharatanm-Berry Phase, and Huygens metasurface are discussed. The development of soft metasurface opens up a new dimension of application zone in conformal or wearable photonics. The progress of soft metasurface has also been discussed in this review. Meta-devices that are being developed with the principle of the shaping of wavefronts are elucidated in this review. Furthermore, it has been established that properties of novel optical metasurface can be modulated by the change in mechanical, electrical, or optical stimuli which leads to the development of dynamic metasurface. Research thrusts over the area of tunable metasurface has been reviewed in this article. Over the recent year, it has been found that optical fibers and metasurface are coagulated for the development of optical devices with the advantages of both domains. The metasurface with lab-on fiber-based devices is being discussed in this review paper. Finally, research trends, challenges, and future scope of the work are summarized in the conclusion part of the article.

Multibeam and Beam Scanning With Modulated Metasurfaces

Article

Full-text available

Mar 2020

Multibeam and beam scanning capabilities of modulated metasurface (MTS) antennas using multiple feeds are investigated. The MTS synthesis is performed by direct inversion of an Electric Field Integral Equation (EFIE) obtained after expanding the unknown equivalent impedance profile into Fourier-Bessel Basis Functions. Two approaches are explored. The first one assumes a priori a discrete azimuthal symmetry in the impedance profile, so as to constrain the solution to a subspace which automatically provides multiple beams when illuminated with feeds regularly arranged along azimuth. In the second approach, there are not a priori assumptions on the impedance profile, but the systems of equations corresponding to each beam are stacked and solved simultaneously in the least-squares sense. This second approach can also be used to obtain polarization diversity. More importantly, it also enables continuous beam scanning. The latter functionality is achieved through the generation of two embedded patterns in a common azimuthal window with opposite phase slopes, followed by a continuous phasing of the two feed points. Various designs are presented in the paper. All the results are validated with the Method of Moments (MoM).

Metasurface Antennas: New Models, Applications and Realizations

Article

Full-text available

Jul 2019

This paper presents new designs, implementation and experiments of metasurface (MTS) antennas constituted by subwavelength elements printed on a grounded dielectric slab. These antennas exploit the interaction between a cylindrical surface wave (SW) wavefront and an anisotropic impedance boundary condition (BC) to produce an almost arbitrary aperture field. They are extremely thin and excited by a simple in-plane monopole. By tailoring the BC through the shaping of the printed elements, these antennas can be largely customized in terms of beam shape, bandwidth and polarization. In this paper, we describe new designs and their implementation and measurements. It is experimentally shown for the first time that these antennas can have aperture efficiency up to 70%, a bandwidth up to 30%, they can produce two different direction beams of high-gain and similar beams at two different frequencies, showing performances never reached before.

Method of Anisotropic Metasurface Unit Cell Surface Impedance Calculation

Conference Paper

Jun 2021

LEO Satellite Multibeam Coverage Area Division and Beamforming Method

Article

Jul 2021

The LEO satellite has a large communication angle, resulting in a large difference in path loss at different angles. The existing multi-beam coverage area division method cannot meet the coverage requirement of the effective isotropic radiated power (EIRP) in these large-angle areas. Therefore, this paper proposes a method for dividing the beam coverage area from the outside to the inside. Combined with the subarray multi-beam forming method, it achieves the optimal coverage of isoflux multiple beams to the ground with unchanged output power of the transmitter, which greatly improves the overall efficiency of existing beam-forming methods. At the meantime, a frequency reuse color separation algorithm based on the depth first search (DFS) is proposed to reduce the mutual interference among non-uniform multiple beams. As an example, 52 beams with 12-color frequency reuse are designed to cover 55. The edge EIRP of a single beam is no less than 25.5 dBW and the carrier-to-interference ratio (C/I) is no less than 16 dB.

An Orthogonal Hybrid Analog-Digital Multibeam Antenna Array for Millimeter-Wave Massive MIMO Systems

Article

Aug 2020

A hybrid analog-digital multibeam antenna array (MBAA) consisting of two types of one-dimension beamformers for two orthogonal planes, respectively, is proposed for massive multiple-input multiple-output (MIMO) communication systems at millimeter-waves. In the vertical direction, the multiple beams are generated by a passive beamformer, i.e. a Butler matrix, whereas the multibeam coverage in the horizontal plane is achieved digitally at the baseband. Comparing to a full-digital multibeam array, the digital beamforming (DBF) processing is simplified in the proposed scheme, significantly alleviating the computational burden of data processing. Since the radiation beams are generated by only a part of the radio frequency (RF) channels in the hybrid multibeam array, the power consumption could be reduced by powering down the idle channels. To verify the concept, a two-dimensional (2D) array comprised by 16 columns of 8-beam tapered slot antenna sub-arrays is designed and fabricated, in which each sub-array contains a pair of 4 × 8 modified Butler matrices based on substrate integrated waveguide technology. The measured results exhibit that the operating bandwidth is 13.45% for the sub-array fed by the modified Butler matrices implemented by substrate integrated waveguides. The RF receivers, intermediate frequency (IF) chains, and analog-to-digital converters (ADC) are also implemented to enable the DBF in the horizontal plane. The maximum simulated directivity of the array is 27 dBi. A wide 2D spatial angle is covered simultaneously by the proposed hybrid passive-digital beamforming scheme. The demonstrated 2D millimeter-wave hybrid array may find widespread potential applications in future communication systems.

Large‐Area 3D‐Printed Chiral Metasurface Composed of Metal Helices

Article

Jul 2018

An original design for chiral metasurfaces formation is proposed. The hybrid fabrication approach is based on the 3D printing of polymer substrates with a shape‐generating “helical” relief, molding, and subsequent shadow metal deposition. The formed double‐layer grating of multiturn metal helices rotates the polarization plane of sub‐terahertz and microwave radiation through an angle in excess of 40°. Both experimentally and in numerical simulations, it is demonstrated that re‐reflection phenomena occur in the “metal helix–polymer substrate” hybrid structure. Those phenomena permit control of polarization‐plane rotation, ellipticity, and asymmetric transmission. Multiplication of printed structures with 3D helices achieved by using the molding technique enables the formation of large‐area chiral metasurfaces. The advantages of the proposed metasurface include easy fabrication of the system, the possibility of its scalability to other frequency ranges, and the possibility of using systems based on such metasurfaces in highly efficient polarization transformers. Combining the 3D printing technology, molding, and deposition of metal films, an original design of hybrid chiral metasurfaces is introduced. The formed structures rotate the polarization plane of sub‐terahertz and microwave radiation in excess of 40°. The advantages of the metasurfaces include easy fabrication, scalability to other frequency ranges, and the possibility of using as highly efficient polarization transformers.

Multibeam Antenna Implementation Using Anisotropic Metasurfaces

Figures

Recommended publications

Numerical implementation of the mixed potential integral equation for planar structures with ferrite...

Design of a multibeam metasurface antenna for LEO satellite communications payload

A Multi-Beam Antenna Based on Modulated Metasurface

Multi-Beam Dual Polarised Metasurface Antenna in Ka-band

A Low Profile Modulated Metasurface Antenna for Multi-Beam Applications