MIMO Antenna Array Research Articles

Compact high isolation MIMO antenna array for 6G application (0.1–10 THZ)

ABSTRACT In wireless communication, channel capacity and reliability can be increased using a Multiple Input Multiple Output antenna. For several future applications, the sixth generation terahertz frequency spectrum (0.1–10 THz) will be used to increase the communication speed in wireless networks. To minimise coupling and reconfiguration, the decoupling structure and pin diodes are used in the MIMO antenna. This research presents a four-port electromagnetic band gap-based MIMO antenna array for 6 G applications. The entire MIMO system is influenced by the electromagnetic coupling between the four or eight MIMO parts. In the ground plane, antenna size reduction, insulation improvement, and defective ground are used. Here, the antenna is designed and compared using the two substrates Flame Retardant and polyimide. The performance of the suggested design is 288 GHz Polyimide and 301.6 GHz FR4. The suggested design showed better performance of the antenna as well as diversity measures.

Machine learning-based technique for directivity prediction of a compact and highly efficient 4-port MIMO antenna for 5G millimeter wave applications

Miniaturized Millimeter Wave (mm-wave) MIMO antenna arrays with an observed 10-dB impedance broad bandwidth of 3.7 GHz (25.785–29.485) are the focus of this study's design and analysis for a 5G application. Rogers RT/duroid 5880, a low-loss dielectric material, is utilized in the antenna's fabrication. For MIMO antenna design down to the lowest frequency, the substrate and ground must have dimensions of 3.3λ0 × 3.3λ0. Besides compact, the suggested design has a supreme gain of 8.9 dB, isolation greater than 29.24, and a maximum efficiency rating of 98.4 %. A Diversity Gain (DG) has a value that is greater than 9.99, whereas an Envelope Correlation Coefficient ECC) has a value that is less than 0.00005. The effectiveness of machine learning (ML) models can be estimated using a variety of different metrics, including the variance score, R square, mean square error (MSE), mean absolute error (MAE), and root mean square error (RMSE). Out of the five ML models, the one that has the greatest accuracy and has a low margin of error when predicting directivity is the Random Forest Regression model. In conclusion, the data from the CST and ADS modeling as well as the actual and expected outcomes from machine learning demonstrate that the recommended antenna is a potential candidate for use with 5G.

Small-Size Eight-Element MIMO Metamaterial Antenna with High Isolation Using Modal Significance Method.

This article presents a symmetrical reduced-size eight-element MIMO antenna array with high electromagnetic isolation among radiators. The array utilizes easy-to-build techniques to cover the n77 and n78 new radio (NR) bands. It is based on an octagonal double-negative metamaterial split-ring resonator (SRR), which enables a size reduction of over 50% for the radiators compared to a conventional disc monopole antenna by increasing the slow-wave factor. Additionally, due to the extreme proximity between the radiating elements in the array, the modal significance (MS) method was employed to identify which propagation modes had the most impact on the electromagnetic coupling among elements. This approach aimed to mitigate their effect by using an electromagnetic barrier, thereby enhancing electromagnetic isolation. The electromagnetic barriers, implemented with strip lines, achieved isolation values exceeding 20 dB for adjacent elements (<0.023 λ) and approaching 40 dB for opposite ones (<0.23 λ) after analyzing the surface current distribution by the MS method. The elements are arranged in axial symmetry, forming an octagon with each antenna port located on a side. The array occupies an area of 0.32 λ2 at 3.5 GHz, significantly smaller than previously published works. It exhibits excellent performance for MIMO applications, demonstrating an envelope correlation coefficient (ECC) below 0.0001, a total active reflection coefficient (TARC) lower than -10 dB for various incoming signals with random phases, and a diversity gain (DG) close to 20 dB.

A quad-port triple-band high isolation terahertz MIMO antenna for short-distance THz communication links

This paper introduces an arrangement of a Multiple-Input Multiple-Output antenna array implemented specifically for operating within the THz frequency bands. The antenna is designed for short-distance THz communication links. A quad-port MIMO antenna configuration has been chosen to function across three frequency bands. Each cell element is situated on top of a silicon substrate. The combined cross-sectional surface of the MIMO antenna is 70 × 50 µm². The proposed MIMO antenna device reaches the following three frequency bands: 2.6–7.9 THz, 9.66–10.3 THz and 11.5–14.1 THz. In addition, the mutual coupling coefficient is less than − 20 dB, indicating strong isolation between antenna elements. This high isolation is obtained by using a defected sibstrat structure and a specifique distance between antenna elements. The MIMO array antenna attains peak gains of 11.88 dBi, 8.78 dBi and 10.65 dBi when operating over the three cited bandwidth. Furthermore, the suggested MIMO structure exhibits favorable characteristics with CCL < 0.5 bps/Hz/sec, MEG ≤ –3.0 dB, ECC < 0.01, and DG ≈ 10 dB, over the operating bands. Based on the results obtained and compared to several works reported in the literature, the proposed implementation maintains a good size-performance compromise which allows better adaptation to applications requiring versatile performance in various communication scenarios.

Quad-Band 1 × 4 Linear MIMO Antenna for Millimeter-Wave, Wearable and Biomedical Telemetry Applications.

In this paper, we present the design of a millimeter-wave 1 × 4 linear MIMO array antenna that operates across multiple resonance frequency bands: 26.28-27.36 GHz, 27.94-28.62 GHz, 32.33-33.08 GHz, and 37.59-39.47 GHz, for mm-wave wearable biomedical telemetry application. The antenna is printed on a flexible substrate with dimensions of 11.0 × 44.0 mm2. Each MIMO antenna element features a modified slot-loaded triangular patch, incorporating 'cross'-shaped slots in the ground plane to improve impedance matching. The MIMO antenna demonstrates peak gains of 6.12, 8.06, 5.58, and 8.58 dBi at the four resonance frequencies, along with a total radiation efficiency exceeding 75%. The proposed antenna demonstrates excellent diversity metrics, with an ECC < 0.02, DG > 9.97 dB, and CCL below 0.31 bits/sec/Hz, indicating high performance for mm-wave applications. To verify its properties under flexible conditions, a bending analysis was conducted, showing stable S-parameter results with deformation radii of 40 mm (Rx) and 25 mm (Ry). SAR values for the MIMO antenna are calculated at 28.0/38.0 GHz. The average SAR values for 1 gm/10 gm of tissues at 28.0 GHz are found to be 0.0125/0.0079 W/Kg, whereas, at 38.0 GHz, average SAR values are 0.0189/0.0094 W/Kg, respectively. Additionally, to demonstrate the telemetry range of biomedical applications, a link budget analysis at both 28.0 GHz and 38.0 GHz frequencies indicated strong signal strength of 33.69 dB up to 70 m. The fabricated linear MIMO antenna effectively covers the mm-wave 5G spectrum and is suitable for wearable and biomedical applications due to its flexible characteristics.

A Novel Flying Robot Swarm Formation Technique Based on Adaptive Wireless Communication using MUSIC Algorithm

This paper presents a novel technique to address the challenge of coordinating swarm flying robots in a leader-follower configuration. A combination of the Multi Signal Classification (MUSIC) estimation algorithm, based on a wireless MIMO array antenna, along with onboard robot control are used for precise route tracking of an individual robot. Employing an array antenna reduces energy consumption for followers in passive mode and reduces computational complexity when measuring the angles of leader angle interferences, which depends on the phase difference of the impinging signal on the antenna elements of the array. Additionally, the angles estimation and beamforming processes, utilizing MUSIC algorithm, form an inner loop that furnishes orientation angles in 3D (Azimuth and elevation angles) for both the leader and potential interference sources. The outer loop, contingent on the onboard controller and the robot's GPS system, enabling fine adjustments in angle and position relative to the leader's location. The simulation results illustrated the efficiency of the proposed technique in estimating the orientation angles of the leader and the interference sources. The technique robustness is confirmed through testing the performance on different trajectories. Where the follower perfectly generates a main radiation beam directed towards the leader, effectively mitigates interference signals from neighboring group leaders, and successfully tracks the leader path.

Dual-band THz-massive MIMO antenna array with beamforming for 5G and beyond networks

Dual-band THz-massive MIMO antenna array with beamforming for 5G and beyond networks

Design and Fabrication of Compact MIMO Array Antenna with Tapered Feed Line for 5G Applications

In this paper, we design, fabricate, measure, and report two proposed multiple input multiple output antenna elements (MIMOs) with good performance in the 5G band. The MIMO antennas are mounted on Roger / Druoid 5880 substrates (dielectric constant: 2.2) with an overall structure volume 20×24.14×0.79mm3. First, a comprehensive parametric study is performed based on CST Electromagnetic (EM) Simulator to investigate and enhance the antenna performance in relation to 5G application requirements. Second, as part of the antenna design process, we compute the envelope correlation coefficient (ECC &gt; 0.01dB) and diversity gain (DG&gt; 9.9dB) and achieve good results. Third, we provide fabrication and measurement verification with good agreement. Fourth, we use a tapered feed structure with inset feed to minimize mutual coupling and achieve matching along 2 transmission lines with various impedances with high compactness in the antenna structure. Fifthly, we report that the proposed antenna structure has a gain is 8 dBi (dB) at the relevant operating frequency band (24.25

Scalability of MIMO Antennas: Assessing Gain and HPBW for Different Antenna Element Configurations

The design of Massive MIMO Antennas presents challenges due to their large size, which can impede the design process. Additionally, the arrangement of multiple antenna elements in Massive MIMO Antennas poses a challenge, as it surpasses the capabilities of simulation software and involves complex procedures. Therefore, to address these issues, a scalability technique utilizing array factor theory is employed to determine the relationship between the configuration of MIMO antennas and the corresponding values of gain and half-power beamwidth (HPBW). By utilizing a simpler MIMO Antenna array with incremental configurations, such as 2x2, 4x4, 8x8, and 16x16 MIMO element schemes, the array factor theory allows for the prediction of the gain and HPBW values for a Massive MIMO Antenna array with a specific configuration. This research aims to explore the scalability process and derive equations that relate the gain and HPBW values to the different MIMO configurations. The designed MIMO antenna arrangement is based on rectangular antennas with truncated corners and circular antennas with X slots, allowing for the investigation of various configurations operating at a frequency of 3.5 GHz.

Quad port P-shaped MIMO antenna array for 60 GHz applications

This article describes the design and fabrication of a 4 × 4 MIMO antenna array intended for operation at 60 GHz. The antenna comprises of half-circular p-shaped radiator connected with a microstrip line printed on the Rogers 4003 substrate of area 22.5 × 22.5 mm2 with εr, thickness, and tan δ of 3.5, 0.203 mm, and 0.0027, respectively. This single radiator is doubled and connected to the power divider to obtain a 1 × 2 antenna array for gain enhancement purposes. The array model is duplicated on the same substrate to achieve 2 ports and 4 ports MIMO antenna. Thereafter, the model is experimentally fabricated and tested to validate the simulated results. The measured results demonstrate the antenna's 60 GHz operating bandwidth extended from 57 GHz to 63 GHz and with insertion losses ≤ −30 dB between ports (1,2) and (1,4) (the orthogonal ports), while it equals around ≤ −23 dB between ports (1,3) (the mirrored ports) within the achieved band with good consistency between both simulated and tested results. Also, it has achieved a gain of more than 9 dBi at 60 GHz with a broadside radiation pattern in both planes. Furthermore, the MIMO parameters are also carried out (ECC, DG, CCL, MEG, and TARC). The ECC is below 0.0025, the DG is approximately 10 dB, the CCL is below 0.2 bits/s/Hz, the MEG is −3 dB and the TARC is below −10 dB over the achieved frequency band. All the MIMO parameters are investigated to prove the diversity characteristics of the antenna array which supports the antenna to be suitable for the 60 GHz communication.

SICL-Based Multifunctional MIMO Antenna Array for 5G and Beyond (B5G) Applications

SICL-Based Multifunctional MIMO Antenna Array for 5G and Beyond (B5G) Applications

Design and analysis of frequency agile LP to CP convertor loaded silicon–graphene based MIMO array antenna in THz regime

Design and analysis of frequency agile LP to CP convertor loaded silicon–graphene based MIMO array antenna in THz regime

Design and analysis of MIMO antenna array for TeraHertz communication

Design and analysis of MIMO antenna array for TeraHertz communication

Terahertz MIMO antenna array for future generation of wireless applications

Abstract The paper proposes a high gain, low ECC, and high isolation THz MIMO antenna array for future generation wireless applications to accommodate a growing population of mobile users. A THz MIMO antenna array is designed with dimensions of 1200 × 2200 × 191.29 µm3. It employs the array of double-slit complementary split-ring resonators (D-CSRRs) on the bottom layer to improve the gain, return loss, and isolation. The gain of the proposed antenna array is 11.3 dBi with 66.45 % radiating efficiency at 0.65 THz. The −10 dB impedance bandwidth lies from 0.62–0.66 THz. The parameters of the MIMO antenna are evaluated such as isolation, envelope correlation coefficient (ECC), diversity gain (DG), and channel capacity loss. The ECC and DG value observed are 2.84 × 10−6 and 9.98 dB, respectively, at 0.65 THz. The channel capacity loss and isolation of the proposed MIMO antenna array are below 0.4 bps/Hz and (|S 21| &gt; 25 dB), respectively, in the complete operating band. The suggested THz MIMO antenna array can be utilised for THz high-speed wireless communication, video-rate imaging systems, sensing, the medical field for cancer imaging, security scanning, and the detection of illicit goods.

Application of Genetic Algorithm for Synthesizing Onedimensional Thinned Antenna Arrays to form Twodimensional Thinned MIMO Antenna Arrays

The possibility of using thinned classical linear antenna arrays to synthesize two-dimensional thinned MIMO antenna arrays on their basis is considered. The MIMO antenna array which receiving and transmitting elements are located on two mutually orthogonal lines is regarded. On the example of this array it is shown that the directivity diagram of its virtual aperture has the property of separability of spatial variables. It allows using the arrangement of elements of a thinned classical linear antenna array for the receiving and transmitting elements lines. It is demonstrated that a thinned MIMO antenna array can form a radiation pattern with a lower level of side lobes than a full array while keeping the width of the main lobe unchanged. The dependence allowing to determine the peak level of side lobes of a twodimensional thinned MIMO antenna array at a given thinning factor is given.

Design and Performance Evaluation of Orthogonally Polarized Corporate Feed MIMO Antenna Array for Next-Generation Communication System

Design and Performance Evaluation of Orthogonally Polarized Corporate Feed MIMO Antenna Array for Next-Generation Communication System

High gain metamaterial-based 3D cross-shaped THz 16-port massive MIMO antenna array for future wireless network

High gain metamaterial-based 3D cross-shaped THz 16-port massive MIMO antenna array for future wireless network

Wideband 4-port MIMO antenna array using fractal and complimentary split-ring structure for Ku-band appliances

This article presents the wideband compact 4-port fractal MIMO antenna array for Ku-band applications. It incorporates the Koch snowflake fractal in combination with a complementary split-ring resonator (CSRR) to achieve both miniaturization and a broad bandwidth. Further, to improve the effectiveness of the single-driven element, the 2-element linear array is constructed, fabricated, and tested. The single-driven element and the constructed array give good performance results. For pattern diversity, a 4-port MIMO configuration is developed and tested. The proposed MIMO array geometry realizes a wide bandwidth of 13.6−17.5 GHz, fractional bandwidth of 25.08%, a maximum gain of 6.95 dBi, and radiation efficiency of beyond 90% with superior isolation (>−30 dB). It provides better diversity performance parameters (Envelope correlation coefficient <0.001) over the resonating band. Also, channel capacity loss (CCL) <0.11 bit/s/Hz and the total active reflection coefficient (TARC) <−10 dB, parameters are perceived to be within adequate range. Therefore, the designed compact fractal antenna, 2-element array, and 4-port MIMO array are applicable for wide Ku-band applications.

Scalable modular massive MIMO antenna of rectangular truncated corner patch antenna and circular slotted X patch antenna for 5G antenna communication

Massive MIMO Antenna Design results in a very large antenna size that hinders the design process. The arrangement of Massive MIMO Antennas which consists of many antenna elements is a challenge in the design process due to the limited capability of the simulation software and the complicated process. Thus, a scalability technique is used to predict the specification results produced by a Massive MIMO Antenna array with a certain configuration based on a simple MIMO Antenna array with a 2x2, 4x4, 8x8, 16x16 MIMO element configuration scheme, etc. exponential increments. This research will discuss the scaling process to predict the specifications of a Massive MIMO Antenna array. The designed MIMO antenna arrangement is based on the design of a rectangular antenna with a truncated corner and a circular antenna with an X slot for further design with various types of configurations that work at a frequency of 3.5 GHz.

A Quad-Port Design of a Bow-Tie Shaped Slot Loaded Wideband (24.2–30.8GHz) MIMO Antenna Array for 26/28GHz mm-Wave 5G NR n257/n258/n260 Band Applications

This paper describes a four-port MIMO antenna array design featuring bow-tie-shaped slot-loaded patches with wideband capabilities that cover the frequency range from 24.2[Formula: see text]GHz to 30.8[Formula: see text]GHz. The proposed antenna design is printed on an FR4 substrate and occupies an area of 25[Formula: see text]×[Formula: see text]24[Formula: see text]mm2. The MIMO antenna consists of four antenna arrays that are symmetrically placed in an upper-lower configuration. The bow-tie-shaped slots loaded radiators are separated horizontally by 3.48[Formula: see text]mm and vertically by 5.94[Formula: see text]mm. Each antenna array contains two elements that are separated by a distance of wavelength/4. The suggested MIMO antenna array delivers a high gain of 19.09[Formula: see text]dB at 27.8[Formula: see text]GHz and has a bandwidth of 6.6[Formula: see text]GHz that covers the frequency band of 24.2–30.8[Formula: see text]GHz. The research demonstrates the quality of the proposed MIMO antenna through various diversity parameters such as mutual coupling, port correlation, diversity gain, and data rate that can be transmitted over a communication medium. The simulation results are validated and found to be consistent with the experimental results. The presented antenna covers the entire bandwidth allocated to different regions, including Europe (24.25–27.5[Formula: see text]GHz), Sweden (26.5–27.5[Formula: see text]GHz), USA (27.5–28.35[Formula: see text]GHz), China (24.25–27.5[Formula: see text]GHz), Japan (27.5–28.28[Formula: see text]GHz), and Korea (26.5–29.5[Formula: see text]GHz). The proposed MIMO antenna design could be an excellent option for 26/28[Formula: see text]GHz 5G NR n257, n258, and n260 bands under mm-wave wireless communication systems.