Multibeam Antenna Research Articles

Inter-beam handover schemes for LEO satellites in 5G satellite–terrestrial integrated networks

Unlike terrestrial handover schemes, the handover schemes in 5G satellite–terrestrial integrated network (STIN) face several challenges, such as large propagation delay, complex channel environment, and fast satellite movement. Therefore, the handover schemes designed in the 5G terrestrial network is not suitable for the 5G STIN. In view of this, this paper considers the inter-beam handover problem for the 5G STIN with a low earth orbit satellite and a ground user. We establish the satellite channel model, which includes path loss, rain attenuation, and multi-beam antenna gain. To model the mobile feature of the user, we consider a two-dimensional random walk model. Then, we propose A5 event-based conditional handover (CHO) scheme, time factor-based CHO scheme, and load factor-based CHO scheme to achieve efficient inter-beam handover. Considering that there may be multiple beams that meet the triggering condition in each handover scheme, we also propose three kinds of beam selection schemes, namely random beam selection scheme, maximum power-based beam selection scheme, and minimum distance-based beam selection scheme. To evaluate the performance of the proposed handover schemes, key performance indicators, such as handover frequency, ping-pong handover rate, unnecessary handover rate, handover failure rate, and average transmission rate are analyzed. Simulation results verify the superiority of the proposed handover schemes by comparing them with the benchmark scheme.

Advanced directional beam control via holographic acoustic metasurfaces for multibeam scanning

Acoustic multi-beam leaky-wave antennas, designed with holographic metasurfaces, have great potential for beamforming by achieving directional beam control. We propose a planar holographic metasurface for beam steering using multi-beam acoustic radiation serving as high-gain acoustic leaky wave antennas. Based on the principle of holography, we designed a metasurface that adjusts its admittance in a sinusoidal pattern. This surface consists of periodic cylindrical holes with varying depth profiles. A monopole point source is positioned in the middle of the patterned surface, which generates surface waves on the modulated surface and emits acoustic leaky-wave radiation in the desired directions. The holographic admittance surface is designed to radiate an acoustic beam at a frequency of 20 kHz. Additionally, the concept was extended to generate multi-beam scanning for forward leaky-wave radiation in the holographic process. In this research, we employed 3D additive manufacturing to create acoustic holograms, manipulating surface admittance variation at a resolution smaller than the wavelength. The experimental measurements aligned well with both the theoretical and numerical analysis findings, affirming the effectiveness of the proposed technique. The methodology exhibits broad applicability across various domains, including sonar, ultrasound imaging, waveform manipulation, and acoustic communication.

Gain Enhancement of Dual-Polarized 2-D Multibeam Antenna With Transmitarray

Gain Enhancement of Dual-Polarized 2-D Multibeam Antenna With Transmitarray

Особенности структурного синтеза алгоритмов обработки радиолокационной информации при многочастотном наблюдении

Setting and solving the problem of structural synthesis of the algorithm for detecting and measuring parameters of mobile objects against the background of correlated interference and noise in multi-frequency radar surveillance systems based on multibeam digital antenna arrays are considered. The processing algorithm is synthesized under the assumption of Gaussian observation statistics with separate spatial and temporal characteristics of signals and interference. As part of the study, a phenomenological model of the radar situation was developed, adequate to the formation of observations in multi-frequency space-time signal processing systems against the background of correlated interference and noise. On its basis, a structure of an optimal, in terms of Bayesian quality criteria, algorithm for detecting a multi-part signal at the outputs of multipath digital antenna arrays is obtained. On the basis of the adaptive Bayesian approach, ways of solving the problem of detecting and measuring parameters of mobile objects in conditions of multi-frequency observations with parametric a priori uncertainty about interference characteristics are determined. Recommendations on selection of adaptive algorithms for radar information processing in case of non-stationary observations are given. The results of structural synthesis make it possible to present processing in the form of a multichannel system in space, time and radial speed. Sufficient statistics on the set of radiation frequencies are accumulated. This view opens up a wide range of possibilities for using parallel computing systems. It is shown that the obtained algorithms can serve as the basis for detecting the beginning of maneuvering of an observation object at the stage of primary processing of radar information.

Design and implementation of a multibeam filtering antenna array using compact 3 × 3 Nolen matrix aided by grey wolf algorithm

This paper presents a novel multibeam filtering antenna array based on a compact 3 × 3 Nolen matrix integrated with HRR filters for solar observations. The design facilitates the simultaneous recording of solar radio flux density and sky background flux density, streamlining calibration processes. The use of stub-loaded transmission line (SLTL) couplers achieves a significant 43.4% reduction in the size of the Nolen matrix, enhancing compactness. The hairpin ring resonator (HRR) filter with two transmission zeros (TZs) is employed to ensure electromagnetic compatibility (EMC). Given the limitations of conventional manual design methods, the intelligent grey wolf algorithm (GWA) is adopted to optimize the physical parameters of the Nolen matrix layout, realizing rapid and accurate achievement of the desired performance. The −6.2±0.15 dB transmission coefficient and 0°, −120°and +120°of output phase differences within 2° phase error are accomplished at 2.8 GHz. Finally, the proposed multibeam filtering antenna array is fabricated and measured to confirm its ability to generate the required three beams with filtering characteristics. The measured results have a good agreement with the simulated results.

Additively-Manufactured Broadband Metamaterial-Based Luneburg Lens for Flexible Beam Scanning

Multi-beam microwave antennas have attracted enormous attention owing to their wide range of applications in communication systems. Here, we propose a broadband metamaterial-based multi-beam Luneburg lens-antenna with low polarization sensitivity. The lens is constructed from additively manufactured spherical layers, where the effective permittivity of the constituting elements is obtained by adjusting the ratio of dielectric material to air. Flexible microstrip patch antennas operating at different frequencies are used as primary feeds illuminating the lens to validate the radiation features of the lens-antenna system. The proposed Luneburg lens-antenna achieves ±72° beam scanning angle over a broad frequency range spanning from 2 GHz to 8 GHz and presents a gain between 15.3 dBi and 22 dBi, suggesting potential applications in microwave- and millimeter-wave mobile communications, radar detection and remote sensing.

A review: Performance of multibeam dual parabolic cylindrical reflector antennas in LEO satellites

The characteristics of multibeam dual parabolic cylindrical reflector antennas are summarized in this article. They can generate an arbitrary number of beams with arbitrary tilt angles for each beam. They can be remotely controlled to cover any arbitrary area, of any shape and size, even if the antenna was mounted on a quasi-stationary platform. Their performance in Low-Earth Orbit (LEO) satellites and ground stations (terminals) have been presented. A simple beam tracking technique was developed. For any specific satellite orbit, the orientation of the ground-station antenna could be adjusted such that its beams are parallel to the satellite's beams and directed toward them. The ground-station antenna can simultaneously communicate with multiple satellites in different orbits. A single antenna can cover the whole mm-band (17.8-30 GHz), which is one of the most widely used bands in LEO satellites. The overall size of a mm-wave antenna, generating 20-24 dB gain, is 14.8x10.4x3.7 cm3 and its weight is 0.37 kg.

Adaptive multibeam hopping in geo satellite networks with non-uniformly distributed ground users

This paper designs a novel low-complexity user-cluster grouping algorithm for adaptive beam hopping in geostationary satellite networks equipped with multibeam phased-array antennas. Each beam serves a cluster of users, and the challenge is to design a beam-hopping pattern where no beams are simultaneously serving nearby user clusters. We develop a line search procedure to identify near-optimum groupings for heterogeneous traffic demands. We provide a necessary condition to determine the boundaries of the line search space. Our approach employs exclusion regions around critical user clusters in congested areas, iterates a sequential congestion-based grouping algorithm, and applies a group-member-swapping procedure. It provides max-min fairness for ground users. Extensive numerical studies have shown that our user grouping algorithm produces near-optimum beam-hopping schedules with low outage probability. It achieves an improvement of up to 13dB in the worst-case signal-to-interference and noise ratio, and doubles the zero-outage data rate, compared to benchmark approaches.

Cognitive radio network architecture for GEO and LEO satellites shared downlink spectrum

The fixed spectrum assignment policy in the space sector and large constellations of Low Earth Orbit (LEO) satellites left little or no spectrum available for future LEO satellite communications services. Cognitive Radio (CR) technology enables spectrum sharing between primary and secondary users without limiting the transmission power, and thus is of great interest to commercial and defense entities. A number of Radio Environment Map (REM) techniques have been making Cognitive Radio Networks (CRNs) practical by constructing a comprehensive map of the CRN by utilizing multi-domain information from geolocation databases, characteristics of spectrum use, geographical terrain models, propagation environment, and regulations. In this paper, we investigate spectrum sharing for a network comprised of a Geostationary Orbit (GEO) and a LEO satellite with a multibeam antenna array. A CRN architecture of GEO and LEO satellites shared downlink spectrum is proposed and details are provided covering its architecture, REM structure and channel utilization data aggregation, as well as a frequency slot assignment mechanism.

2-D Steerable Multi-Beam Antenna for Concurrent Wireless Communication Systems

2-D Steerable Multi-Beam Antenna for Concurrent Wireless Communication Systems

Shape Optimization Design Method of High-Performance Multibeam Antenna for Mixed-Payload Communication Satellite

Shape Optimization Design Method of High-Performance Multibeam Antenna for Mixed-Payload Communication Satellite

Review of Luneburg Lens Antenna Designs Manufactured Using 3D Printing

Introduction. The interest in multibeam dielectric lens antenna arrays has been growing in recent years due to the development of millimeter-wave telecommunication and radar systems. Progress in the development of mobile communication systems based on adaptive beamforming technology is increasingly associated with multibeam systems based on lens antenna structures, providing an alternative to hard-to-implement and energy-consuming phased antenna arrays. In recent years, spherical and cylindrical Luneburg lens antennas implemented using additive manufacturing technology have attracted research attention. Despite their complexity of execution, these design exhibit excellent electromagnetic characteristics. This paper provides a review of Luneburg lens antennas manufactured using 3D printing, which can find application in 5G and 6G communication systems.Aim. To review achievements in the design of lens antenna structures manufactured using additive manufacturing.Materials and methods. Materials for analysis, comparison, and systematization were derived from various sources, including research articles, publications in proceedings of Russian and international conferences, and websites of manufacturers of lens antennas over the past 20 years. The material selection mechanism was based on the originality of the presented designs of printed Luneburg lens antennas.Results. A review of Luneburg lens antennas manufactured using 3D printing, which differ from each other in terms of mechanical strength, complexity of execution, and electrodynamic characteristics, was carried out. The results of a comparative analysis of the key characteristics of these antennas are presented, along with examples of their practical implementation.Conclusion. The disadvantage of Luneburg lens antennas has always been the complexity of their manufacture; however, additive manufacturing technologies open up new opportunities for their fast, high-quality, and automated production. Various 3D printing technologies can be used to create dielectric lens antennas, which differ in the resolution of printers, printing speed, and cost. Additive manufacturing methods are constantly developing, having reached the technological possibility of printing Luneburg lens for the sub-THz range with a high level of resolution and accuracy. In addition, 3D printers capable of printing multiple lenses simultaneously have also appeared.

An ultrathin wideband linear-to-circular polarization conversion metasurface for X-band applications

A specialized ultrathin metasurface has been developed to transform a linearly polarized incident wave into a reflected wave with circular polarization across a wide range of frequencies. The unit cell consists of two modified L-shaped structures that convert the incident linearly polarized wave to a circularly polarized wave. The axial ratio bandwidth of the reflected wave ranges from 8.19 to 11.08 GHz, exhibiting a fractional bandwidth of 30%. The dimensions of the unit cell are 7 × 7 ×1.6mm3 (0.225λ×0.225λ×0.051λ) where λ represents the center frequency within the operational frequency band. The proposed design not only provides a wide bandwidth but also is ultrathin as the dimensions are much less than λ/12. Finally, the proposed metasurface is fabricated and tested. The results obtained are in significant concurrence with the simulated results. Hence, it can be used in various applications, including implementation in multi-beam antennas, beam-scanning antennas, wireless systems, weather monitoring, radar tracking, and navigation systems.

Mitigation of Feed Horn Overlapping Condition for Multi-beam Parabolic Reflector Antenna

Mitigation of Feed Horn Overlapping Condition for Multi-beam Parabolic Reflector Antenna

Tensor-Free Holographic Metasurface Leaky-Wave Multi-Beam Antennas with Tailorable Gain and Polarization.

Recently, the community has seen a rise in interest and development regarding holographic antennas. The planar hologram is made of subwavelength metal patches printed on a grounded dielectric board, constituting flat metasurfaces. When a known reference wave is launched, the hologram produces a pencil beam towards a prescribed direction. Most earlier works on such antennas have considered only a single beam. For the few later ones that studied multiple beams, they were achieved either by having each beam taken care of by a distinct frequency or by partitioning the hologram, thereby depriving each beam of the directivity it could have had it not shared the holographic aperture with other beams. There have been recent studies related to the use of tensor surface impedance concepts for the synthesis of holograms which have attained control over the polarizations and intensities of the beams. However, this approach is complicated, tedious, and time-consuming. In this paper, we present a method for designing a planar holographic leaky-wave multi-beam metasurface antenna, of which each simultaneous beam radiating at the same frequency towards any designated direction has a tailorable amplitude, phase, and polarization, all without hologram partitioning. Most importantly, this antenna is exempted from the need for the cumbersome technique of tensor impedance. Such features of beam configurability are useful in selective multiple-target applications that require differential gain and polarization control among the various beams. Only a single source is needed, which is another benefit. In addition, effective methods to mitigate sidelobes are also proposed here. Designs by simulations according to the method are herein validated with measurements performed on fabricated prototypes.

Shared Aperture Dual-Band Dual Circularly Polarized Multibeam Antenna for Satellite-Assisted Internet of Vehicles

Shared Aperture Dual-Band Dual Circularly Polarized Multibeam Antenna for Satellite-Assisted Internet of Vehicles

The Design of Broadband Circularly Polarized Multi-beam Antenna with Linearly Polarized Feeding Source and Transmitarray Unit

The Design of Broadband Circularly Polarized Multi-beam Antenna with Linearly Polarized Feeding Source and Transmitarray Unit

Design of multibeam antenna with ultralow cross‐polarization

AbstractThis paper presents a design to realize extremely low cross‐polarization level in multibeam antenna. The antenna consists of two reflectors placed on top of each other. The front reflector is a panel made of metal grid, which is used to separate two orthogonal polarizations. The rear reflector serves as the actual multibeam antenna surface. The multibeam antenna and feed array operated at Ku band are designed and fabricated. The test results show that the gains of the 28 beams can be better than 40.42 dBi, and the cross‐polarization level can be lower than −40 dB. The proposed method provides a novel idea for the design of ultralow cross‐polarization multibeam antenna.

A design of reconfigurable antenna with wide/narrow beam tunability

In this paper, a reconfigurable multibeam antenna with switchable polarization and wide/narrow beam tunability is presented. The antenna consists of a reconfigurable power splitter and a 2 × 2 patch antenna array. The curved patch, as part of the periphery of the antenna unit, is used to switch grounded and ungrounded, so as to achieve wide and narrow beam radiation, respectively. By embedding p-i-n diodes in the power splitter and switching the ON/OFF state, the selection of the output ports and the phase difference between them are achieved. In the process of function selection, polarization switching can be realized by exciting the antenna units at different positions. Beam deflection can be achieved by controlling the phase difference between output ports. To ensure stable and fast switching between beam states, the antenna is controlled by an external micro-control system, which has the advantages of simplicity, stability, and speed. The experimental results show that the antenna can generate 12 beam states, which are in good agreement with the simulation results.

Active Pointing Compensation of a HTS Multibeam Antenna

Active pointing compensation of a High Throughput Satellite (HTS) multibeam antenna via microfiber composites (MFCs) is studied in this paper. Electrical-mechanical coupling analysis of MFCs is conducted to quantitatively determine driving forces and moments of MFCs attached on a carbon fiber reinforced composite (CFRP) laminate, and a positive correlation relationship is observed for driving ability versus thickness of the laminate. By different driving strategies, MFCs could act in bending mode and torsioning mode for structural deformation control, and driving efficiency of the MFCs on a multibeam antenna is studied. Thermal distortion of the antenna under a typical in orbit thermal distribution causes the reflector to rotate about y axis with an pointing error of 0.005°, active compensation is conducted, and the final compensation results show that with an optimal voltage of 432 V, pointing error of the antenna is greatly compensated, and the depointing angle is corrected to be 0.00004°.