Switched-beam Antenna Research Articles

Direction of arrival (DOA) estimation using switched beam antenna with butler matrix at mm-wave frequency

This paper presents a butler matrix-based microstrip hexagonal patch antenna with a direction of arrival (DOA) estimation approach for mm-wave application. The hexagonal-shaped patch antenna had been designed with a Z-shaped slot with an eight-port butler matrix. The DOA estimation is also done for the switched beam antenna using a novel direction of arrival (DOA) estimation algorithm known as Cramer-Rao lower bound (CRLB). The proposed design leads to significant size reduction and loss minimization. In addition to this, the design had the advantages of being low-cost, lightweight, and small-volume. The entire proposed design provides an operating frequency range of 28 GHz to 39 GHz with a center frequency of 33 GHz. The proposed work makes use of two butler matrices with two 45° phase shifters and 120° phase shifters. The effectiveness of the proposed algorithm and antenna design using the Butler matrix is evaluated for various performance metrics separately. The antenna is designed using Rogers RT/duroid 5880(tm) substrate, and the fabricated prototype is studied. The designed antenna attains high radiation efficiency, and it ranges between 97 and 98 % under both the measures and simulated scenarios under the operating frequency range of 28 GHz to 39 GHz.

Wide-Angle Beam-Switching Antenna with Stable Gain Based on a Virtual Image Lens

Beam-switching antennas based on quasi-optical beamformers can provide cost-effective solutions for high-frequency communication applications. Here, we propose a wide-angle beam-switching planar lens antenna based on the recently presented virtual image lens. The antenna operates from 24 to 28 GHz and produces a beam that can be steered in a 100-degrees range in one plane with less than 2 dB simulated gain variation over the angular range and operational band. The performance of the presented antenna is similar to reported lens antennas with stable gain, but the proposed lens requires a smaller refractive index range to be realized, which alleviates the manufacturing.

Multifunctional Switched-Beam Antenna Located on Solar Cell for Vehicular to Satellite Communication

Multifunctional Switched-Beam Antenna Located on Solar Cell for Vehicular to Satellite Communication

DESIGN OF A SWITCHED BEAM ANTENNA SYSTEM USING A 4 × 4 BUTLER MATRIX FOR WIRELESS COMMUNICATION APPLICATIONS

Demand for quality service within the cellular network, which has many cells within the cluster, has certain requirements to satisfy the customer or subscriber at any cost. Hence, a reliable approach to provide quality service to the subscriber is needed, and in that attempt, a switched beam system is proposed, which is composed of a Butler matrix operating at 2 GHz for 5G wireless communication systems. The Butler matrix operates at 2 GHz, however, and has an overall bandwidth of 1.2 GHz, ranging from 1.8 GHz to 3 GHz. The beamforming operation is completed by incorporating an antenna array; typically for such applications a linear array with half lambda spacing is preferred. Here, the antenna array is made of a dielectric material, hence forming a dielectric resonator array operating at the same frequency as that of the Butler matrix. To complete the switched beam system, a radiofrequency source is chosen, typically USRP 2900 from National Instruments, to provide excitation to the Butler matrix throughout its operation. The simulation is carried out in Ansys HFSS and PCB Antenna Designer from MathWorks. This article gives the simulation as well as measured results of the Butler matrix and dielectric resonator antenna and draws a conclusion of the performance of the system based on simulated and measured results.

Practical CNN-Based Beam Selection for Wideband Single-Receiver Switched Beam Antenna

Practical CNN-Based Beam Selection for Wideband Single-Receiver Switched Beam Antenna

A Miniaturized Metamaterial-Loaded Switched-Beam Antenna Array System With Enhanced Bandwidth for 5G Applications

A Miniaturized Metamaterial-Loaded Switched-Beam Antenna Array System With Enhanced Bandwidth for 5G Applications

LuMaMi28: Real-Time Millimeter-Wave Multi-User MIMO Systems With Antenna Selection

This paper presents LuMaMi28, a real-time 28GHz multi-user (MU) multiple-input multiple-output (MIMO) testbed. In this testbed, the base station has 16 transceiver chains with a fully-digital beamforming architecture (with different pre-coding algorithms) and simultaneously supports multiple user equipments (UEs) with spatial multiplexing. The UEs are equipped with a beam-switchable antenna array for real-time antenna selection where the one with the highest channel magnitude, out of four pre-defined beams, is selected. For the beam-switchable antenna array, we consider two kinds of UE antennas, with different beam-width and different peak-gain. Based on this testbed, we provide measurement results for millimeter-wave (mmWave) MU-MIMO performance in different real-life scenarios with static and mobile UEs. We explore the potential benefit of the mmWave MU-MIMO systems with antenna selection based on measured channel data, and discuss the performance results through real-time measurements.

Lens-Based Switched-Beam Antenna for a 5G Smart Repeater

Lens-Based Switched-Beam Antenna for a 5G Smart Repeater

A wideband and high‐gain switched‐beam antenna system using active frequency selective surface

AbstractAntennas using the active frequency selective surface (AFSS) can achieve fast beam‐scanning ability at a low cost. In this study, a switched beam antenna with a high gain and 360° coverage in the horizontal plane is proposed. Twelve columns of AFSS form a cylindrical cavity and are transmissive or reflective to the incident electromagnetic waves under the control of PIN diodes. Benefiting from a coaxial continuous transverse stub array placed at the cavity centre and using 4 units to generate a high gain omnidirectional radiation, the proposed antenna can realise a highly directive switched beam. An antenna prototype is designed, fabricated and measured. Results show that it achieves a |S11| < −10 dB bandwidth of 12.9% and is able to sweep its beam around the azimuth plane with a high gain up to 13.6 dBi at 5.8 GHz working frequency.

Novel Low Profile Beam Switchable 5G Sub-6 GHz E-GSM Antenna for Vehicular Communication

ABSTRACT A novel low-profile beam-switchable antenna operating in the Extended Global System for Mobile Communications band of 5G sub-6 GHz for vehicular communication is proposed in this paper. The proposed work has a centre patch that connects with four parasitic radiators and encompasses a tapered patch to R1, R2, R3 and R4 which are slotted loop rectangular patches. The main lobe switching is achieved for Extended GSM by switching between the states of PIN diode circuits, which affects the overall performance of the antenna. With the dimensions of 0.346 λe × 0.346 λe, the presented work exhibits a very-low-profile antenna, having an impedance bandwidth of 14.7% and a peak gain of 1.27 dBi. The proposed beam-switchable antenna incorporates four similar radiators facing different directions affixed to the central square patch director. Each PIN diode is incited eventually to obtain the same resonant frequency at each radiator. The pattern of the proposed antenna can be switched using different states of PIN diodes in the angles of 81°, 171°, 261° and 351°. The prototype is fabricated, and the measured results are in agreement with the simulated results. For the validation of the practicability of the proposed antenna, the far-field analysis is done on the vehicle.

Evaluating the Performance of Proposed Switched Beam Antenna Systems in Dynamic V2V Communication Networks.

This paper develops a novel approach for reliable vehicle-to-vehicle (V2V) communication in various environments. A switched beam antenna is deployed at the transmitting and receiving points, with a beam management system that concentrates the power in each beam using a low-computation algorithm and a potential mathematical model. The algorithm is designed to be flexible for various environments faced by vehicles. Additionally, an anti-failure system is proposed in case the intelligent transportation system (ITS) system fails to retrieve real-time Packet Delivery Ratio (PDR) values related to traffic density. Performance metrics include the time to collision in seconds, the bit error rate (BER), the packet error rate (PER), the average throughput (Mbps), the beam selection probability, and computational complexity factors. The proposed system is compared with traditional systems. Extensive experiments, simulations, and comparisons show that the proposed approach is excellent and reliable for vehicular systems. The proposed study demonstrates an average throughput of 1.7 Mbps, surpassing conventional methods' typical throughput of 1.35 Mbps. Moreover, the bit error rate (BER) of the proposed study is reduced by a factor of 0.1. Additionally, the proposed framework achieves a beam power efficiency of touching to 100% at computational factor of 34. These metrics indicate that the proposed method is both efficient and sufficiently robust.

Beam-Switching Antennas for 5G Millimeter-Wave Wireless Terminals.

Beam-switching is one of the paramount focuses of 28 GHz millimeter-wave 5G devices. In this paper, a one-dimensional (1D) pattern reconfigurable leaky-wave antenna (LWA) was investigated and developed for wireless terminals. In order to provide a cost-effective solution, a uniform half-width LWA was used. The 1D beam-switching LWA was designed using three feed points at three different positions; by selecting the feeds, the direction of the beam can be switched. The antenna can switch the beam in three different directions along the antenna axis, such as backward, broadside, and forward. The 1D beam-switching antenna was fabricated, and because of the wide beamwidth, the measured radiation patterns can fill 128∘ of space (3 dB coverage), from θ = -64∘ to +64∘ at ϕ = 0∘. Following this, two of these antennas were placed at right angles to each other to achieve two-directional (2D) beam switching. The 2D beam-switching antenna pair was also prototyped and tested after integrating them into the ground plane of a wireless device. The antenna is able to point the beam in five different directions; moreover, its beam covers 167∘ (θ = -89∘ to +78∘) at ϕ = 0∘, and 154∘ (θ = -72∘ to +82∘) at ϕ = 90∘.

Deep Reinforcement Learning-Based Adaptive Beam Tracking and Resource Allocation in 6G Vehicular Networks with Switched Beam Antennas

In this paper, we propose a novel switched beam antenna system model integrated with deep reinforcement learning (DRL) for 6G vehicle-to-vehicle (V2V) communications. The proposed system model aims to address the challenges of highly dynamic V2V environments, including rapid changes in channel conditions, interference, and Doppler effects. By leveraging the beam-switching capabilities of switched beam antennas and the intelligent decision making of DRL, the proposed approach enhances the performance of 6G V2V communications in terms of throughput, latency, reliability, and spectral efficiency. The proposed work develops a comprehensive mathematical model that accounts for 6G channel modeling, beam-switching, and beam-alignment errors. The Proposed DRL framework is designed to learn optimal beam-switching decisions in real time, adapting to the complex and varying V2V communication scenarios. The integration of the proposed antenna system and DRL model results in a robust solution that is capable of maintaining reliable communication links in a highly dynamic environment. To validate the proposed approach, extensive simulations were conducted and performance analysis using various performance metrics, such as throughput, latency, reliability, energy efficiency, resource utilization, and network scalability, was analyzed. Results demonstrate that the proposed system model significantly outperforms conventional V2V communication systems and other state-of-the-art techniques. Furthermore, the proposed approach shows that the beam-switching capabilities of the switched beam antenna system and the intelligent decision making of the DRL model are essential in addressing the challenges of 6G V2V communications.

A compact frequency reconfigurable beam switching antenna based on a single‐layer FSS

AbstractA compact frequency reconfigurable beam switching antenna based on a single‐layer frequency selective face (FSS) is proposed in this paper. The proposed antenna consists of a dual‐band dipole antenna and a single‐layer FSS with hexagonally arrangement. The omnidirectional radiation pattern of the dipole antenna designed as a radiation source and surrounded by the FSS can be converted into directional radiation pattern sweeping along the entire azimuthal plane at two single frequency of 2.4 or 5 GHz. The frequency selection is achieved by controlling the diode state of the FSS unit, and the beam switching is realised by a specific combination of electromagnetic wave reflection or transmission from the hexagonal FSS. The novelty lies in applying the hexagonal arrangement to a dual single‐frequency single‐layer FSS unit. This will not destroy the reflection or transmission characteristics of the FSS unit, but also contribute to reduce the antenna size and achieve a low cost. To validate the design, a prototype is fabricated and measured. The single‐layer FSS antenna with a volume of 57 mm × 57 mm × 58.5 mm can be scanned in 12 steps along the azimuth plane at 2.4 and 5 GHz, respectively.

An intelligent humidity control system for mushroom growing house by using beam-switching antennas with artificial neural networks

An automatic humidity control system for mushroom growing house based on the free-space technique is presented. The novelty of this work is the modified free-space technique by measuring the amplitude only of transmission coefficient |<em>S</em><sub>21</sub>| that reflected from mushroom by using beam-switching antenna with artificial neural networks (ANNs) as a humidity sensor to control quantity and time of water misting nozzle. In the proposed system, the antenna is designed to act as the transmitting antenna at the frequency of 2.45 GHz. Its radiation patterns can be switched to 4 directions covering all corners of mushroom growing house. The measured |<em>S</em><sub>21</sub>| from each direction are converted to direct current (DC) voltage by a radio frequency (RF) detector; then are trained with ANNs in the humidity range of 60-85%. The optimized ANNs structure consists of 4 input nodes, two layers of 5 hidden nodes, and 3 output nodes. To verify the proposed system, experiments were set up in controlled humidity mushroom growing house at the humidity level of 75-80% for 120 hours. The results showed that there was slightly average standard deviation (S.D.) of humidity level 1.36. Consequently, the performance of sensor system assures that it is able to apply for humidity control in large growing house.

A suspended conformal patch antenna for a constant-gain beam-switching phased antenna array

In this paper, a suspended conformal patch antenna (SCPA) for improving a constant-gain planar phased antenna array when switching the main beam direction to the desired direction is presented. The beam-switching antenna array is proposed in 4 main beam directions of 0, 15, 30, and 45 degrees. The proposed antenna array is composed of 4 SCPA elements operating at 2.45 GHz. The SCPA consists of an FR-4 substrate and an air gap between the radiator patch and the ground plane. The suspended patch antenna with the conformal patch antenna is used for improving the gain and beamwidth of antenna. The simulation was done using CST Microwave Studio 2021. The comparison results between the SCPA and a suspended planar patch antenna (SPPA) are illustrated with the antenna characteristics such as S-parameters and radiation patterns. The proposed antenna array prototype has been fabricated with SCPA of R=30 mm. The measured results of the antenna characteristics are demonstrated and compared with the simulated results. The measured gain difference between the desired beam directions of 0 and 45 degrees is 2.72 dB. Consequently, the SCPA is very useful for the application in a constant-gain beam-switching phased antenna array.

Switch-Beam Antenna Techniques for Bridge Structural Health Monitoring With GaAs-Based Solar Energy Harvesting

<bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">The structural health monitoring (SHM) of bridges with wireless sensor networks (WSNs) is addressed by leveraging two distinct but interrelated aspects: GaAs-based solar energy harvesting and switched-beam antenna strategies in combination with asynchronous media access control (MAC) protocols. The joint optimization of solar energy harvesting and switched-beam directional antennas at the nodes is considered and compared with an equivalent omnidirectional antenna network. To address the limited energy budget in battery-based sensor nodes which is a serious limitation in long-lived applications such as bridge SHM, an efficient solar harvesting solution is put forth based on the good performance of GaAs cells even under low-light conditions. Given the current state of the art in GaAs cells, single-junction cells were selected due to the cost of double-or triple-junction versions. The simulation model includes the residual energy capacity with GaAs-based solar energy harvesting of actual selected components (microcontroller, radio interface chip). The model was implemented on top of the Omnet<inline-formula> <tex-math notation="LaTeX">$++$</tex-math> </inline-formula> and Silvaco Atlas simulator. The comparative study in this article provides insights into realistic bridge SHM sensor networks, leveraging solar energy harvesting and switched-beam antennas.</b>

High power handling GaAs SP4T Switch-based Beam-Switching planar antenna module for 5G New-Radio FR2 applications

In this paper, a beam-switching antenna module for 5G New-Radio (NR) frequency range 2 (FR2) applications is proposed. The module is constructed with a single-pole-quadruple-throw (SP4T) switch featuring high power handling capability, low insertion loss, and higher isolation, which is integrated with a 4 × 4 Butler matrix and an end-fire antenna array for achieving beam switching characteristics. The system is realized on the Rogers RO3010 substrate which achieved a compact size of 4.67λ0 × 2.06λ0 × 0.031λ0 (f0 = 38 GHz) due to a higher integration level and demonstrated a decent impedance bandwidth of (15.78 %) 35–41 GHz with four beam patterns directing along + 14°, −40°, +49°, and −16°, respectively. The experimental results show an advantage in RF performance with high integration level which is promising for 5G NR n260 band communication applications.

Magnetoelectric Dipole Antennas Loaded With Meta-Lens for 5G MIMO Pattern Diversity Applications

This communication presents a unique design of a dual-polarized wideband passive beam-switching antenna at millimeter-wave (mm-wave) bands for multiple-input–multiple-output (MIMO) pattern diversity applications, which exhibits low correlation between the ports and a broad tilt bandwidth (BW). A magnetoelectric (ME) dipole fed by a printed ridge gap waveguide (PRGW) as a quasi-TE source is considered as the elementary antenna in the Ka-band. To achieve beam deflection in each quadrant, a four-port MIMO prototype consisting of four ME-dipoles, positioned perpendicular to each other, is integrated with a meta-lens that consists of three layers of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$12\times12$ </tex-math></inline-formula> dual-polarized split-ring resonators (SRRs) offset from the center of each antenna. The beamforming structure is able to generate four fixed beams, one in each quadrant at an elevation angle of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 40^{\circ }$ </tex-math></inline-formula> with respect to the broadside direction by exciting each port sequentially, while the other ports are terminated. Moreover, the proposed orthogonal structure contributes to low correlation between the four ports, while achieving dual-polarization, which highlights the suitability of the antenna for 5G mm-wave applications. The measured results from a fabricated prototype demonstrate a −10 dB impedance BW of 40% over 24–36 GHz, tilting BW of 32.2%, and a peak gain of 13.4 dBi at 29 GHz, while an isolation better than 30 dB is achieved over the whole frequency band. Moreover, a measured radiation efficiency in excess of 85% is obtained, due to the use of the low-loss PRGW feedlines.

Machine-learning-based beam steering in a hybrid plasmonic nano-antenna array

In this paper, different beam-steering techniques are introduced using an 8 × 8 hybrid plasmonic nano-antenna array operating at 1550 nm. Two conventional techniques of the switched-beam and phased array are considered for implementing beam steering. For a switched-beam antenna, the beam steering is achieved by switching between the feed antenna elements, whereas the feed antenna array is attached to the back surface of a fishnet achromatic-metalens to collimate the rays. In the phased array antenna, the beam is steered by estimating the appropriate feeding phases of the 64 elements using a deep neural network (DNN) either with or without a lens and comparing the results with those obtained using a traditional method. Finally, a hybrid technique based on activating only a subset of antenna elements in the existence of the lens is proposed to steer the pattern in a certain direction. By predicting the proper feeding phases of the antenna array elements, the neural network with the backpropagation technique and weighted hybrid gravitational search algorithm-particle swarm optimization approach is used to beam-steer the pattern. Furthermore, the DNN is applied to assign the required active subset elements for directing the main beam toward the desired direction. Several sample examples are provided to beam-steer the pattern in numerous directions to assess the correctness of the strategies.