Envelope Correlation Research Articles

High Isolation Wideband MIMO Antenna without Decoupling Technique for IoT Applications

This paper presents a method a high isolation wideband MIMO antenna without using any decoupling technique. This is achieved by transforming a strip line to a 1 ×2 MIMO antenna using Hilbert transform and Defected Ground structure is used in the antenna to resonate the antenna in for IOT and 5G sub-6 GHz bands. The proposed antenna has a size of 50 × 49.8 × 1.6 mm 3 and operates in the frequency band of 4.6 GHz to 5.94 GHz. The antenna simulated in ANSYS HFSS showed that its parameters Envelope correlation coefficient (ECC), Total Active Reflection Coefficient (TARC), Diversity gain (DG) and Channel Capacity Loss (CCL) are less than 0.04, -25 dB, 9.98 to 10 dB and less than 0.4 bits/s/Hz respectively. The radiation pattern of the antenna in both E-plane and H-plane has been simulated which the uniform distribution of power in the space.

Compact dual-port MIMO filtenna-based DMS with high isolation for C-band and X-band applications

A dual-port multiple-input multiple-output (MIMO) filtenna with minimal sizes of 80 × 45 mm2 is set up in this study. Each element in this MIMO filtenna is positioned orthogonally to the one next to it to improve isolation. For the MIMO element to achieve high-frequency selectivity and compact size, a frequency-reconfigurable filtenna that was created by fusing a band-pass filter and a monopole radiator was used. The suggested filtenna can switch between its C-band and X-band operating states with ease. On build the filtenna circuit, a band-pass filter based on defective microstrip structure is inserted to a circular monopole radiator. The developed filtenna operates in the C-band frequency range of 6.5–8 GHz and the X-band frequency range of 8–12 GHz. It is possible to use the X-band operating state for communication in a cognitive radio environment. Used as a decoupling structure, metamaterial structures can increase isolation to more than 40 dB across the bandwidth. The suggested MIMO filtenna system has an envelope correlation coefficient of 2.4e−6, a peak gain of 6 dBi, and an impedance bandwidth of 7.4–7.75 GHz. The MIMO filtenna is constructed and measured, and the findings of the measurement and simulation are in good agreement.

Analyzing the Performance of Millimeter Wave MIMO Antenna under Different Orientation of Unit Element.

In this paper, a compact and simplified geometry monopole antenna with high gain and wideband is introduced. The presented antenna incorporates a microstrip feedline and a circular patch with two circular rings of stubs, which are inserted into the reference circular patch antenna to enhance the bandwidth and return loss. Roger RT/Duroid 6002 is used as the material for the antenna, and has overall dimensions of WS × LS = 12 mm × 9 mm. Three designs of two-port MIMO configurations are derived from the reference unit element antenna. In the first design, the antenna element is placed parallel to the reference antenna, while in the second design, the element is placed orthogonal to the reference element of the antenna. In the third design, the antenna elements are adjusted to be opposite each other. In this study, we analyze the isolation between the MIMO elements with different arrangements of the elements. The MIMO configurations have dimensions of 15 mm × 26 mm for two of the cases and 15 mm × 28.75 mm for the third case. All three MIMO antennas are made using similar materials and have the same specifications as the single element antenna. Other significant MIMO parameters, including the envelope correlation coefficient (ECC), diversity gain (DG), channel capacity loss (CCL), and mean effective gain (MEG), are also researched. Additionally, the paper includes a table summarizing the assessment of this work in comparison to relevant literature. The results of this study indicate that the proposed antenna is well-suited for future millimeter wave applications operating at 28 GHz.

Design and performance analysis of 8‐port multi‐service quad‐band MIMO antenna for automotive communication

AbstractIn this paper, a low profile compact 8‐port multiband antenna with polarization diversity principle for automotive communication is proposed. The geometric of the proposed MIMO antenna is integrated with multiple stubs on substrate having a size of 0.94λg × 0.94λg. The proposed design resonates at multiple frequencies of 1.8, 2.4, 5.2, and 5.8 GHz, respectively for GSM, ISM bands and WLAN wireless services which covers the bandwidth of 2.8%, 5%, 5%, and 5.6%, respectively with S11 ≤ −10 dB. Besides, the measured results provide a peak gain of 4.3, 3.1, 4.5, and 4.2 dBi at 1.8, 2.4, 5.2, and 5.8 GHz, omni directional radiation pattern with more than 80% of efficiency in all operating bands. The MIMO structure provides a good isolation of greater than 20 dB without decoupling structure, envelope correlation coefficient of ≤0.1, diversity gain of ≥9.99 dB, mean effective gain of <1 dB, total active reflection coefficient ≤−10 dB, channel capacity loss of ≤0.25 bits/s/Hz. Finally, the housing effect of MIMO antenna is analyzed in the vehicular environment which provides good performance for Vehicular to Intravehicular communication.

Longitudinal resting-state EEG in amyloid-positive patients along the Alzheimer’s disease continuum: considerations for clinical trials

BackgroundTo enable successful inclusion of electroencephalography (EEG) outcome measures in Alzheimer’s disease (AD) clinical trials, we retrospectively mapped the progression of resting-state EEG measures over time in amyloid-positive patients with mild cognitive impairment (MCI) or dementia due to AD.MethodsResting-state 21-channel EEG was recorded in 148 amyloid-positive AD patients (MCI, n = 88; dementia due to AD, n = 60). Two or more EEG recordings were available for all subjects. We computed whole-brain and regional relative power (i.e., theta (4-8 Hz), alpha1 (8-10 Hz), alpha2 (10-13 Hz), beta (13-30 Hz)), peak frequency, signal variability (i.e., theta permutation entropy), and functional connectivity values (i.e., alpha and beta corrected amplitude envelope correlation, theta phase lag index, weighted symbolic mutual information, inverted joint permutation entropy). Whole-group linear mixed effects models were used to model the development of EEG measures over time. Group-wise analysis was performed to investigate potential differences in change trajectories between the MCI and dementia subgroups. Finally, we estimated the minimum sample size required to detect different treatment effects (i.e., 50% less deterioration, stabilization, or 50% improvement) on the development of EEG measures over time, in hypothetical clinical trials of 1- or 2-year duration.ResultsWhole-group analysis revealed significant regional and global oscillatory slowing over time (i.e., increased relative theta power, decreased beta power), with strongest effects for temporal and parieto-occipital regions. Disease severity at baseline influenced the EEG measures’ rates of change, with fastest deterioration reported in MCI patients. Only AD dementia patients displayed a significant decrease of the parieto-occipital peak frequency and theta signal variability over time. We estimate that 2-year trials, focusing on amyloid-positive MCI patients, require 36 subjects per arm (2 arms, 1:1 randomization, 80% power) to detect a stabilizing treatment effect on temporal relative theta power.ConclusionsResting-state EEG measures could facilitate early detection of treatment effects on neuronal function in AD patients. Their sensitivity depends on the region-of-interest and disease severity of the study population. Conventional spectral measures, particularly recorded from temporal regions, present sensitive AD treatment monitoring markers.

A Four Element Stringray-Shaped MIMO Antenna System for UWB Applications.

This paper presents a CoPlanar-Waveguide (CPW)-fed stingray-shaped Ultra-WideBand (UWB) Multiple-Input-Multiple-Output (MIMO) antenna system designed for microwave imaging applications. Featuring a diagonal square with four inner lines and a vertical line at the center from toe to tip with a CPW feed line, the unit antenna element looks like a stingray fish skeleton and is, therefore, named as a stingray-shaped antenna. It offers a bandwidth spanning from 3.8 to 12.7 GHz. Fabricated on a 31mil RO5880 RF teflon substrate with a relative permittivity of 2.2, the proposed antenna has dimensions of 26 × 29 × 0.787 mm3. The maximum realized gain achieved is 3.5 dBi with stable omnidirectional radiation patterns. The antenna element is used in a four-antenna MIMO configuration with an isolation-improving structure at the center. The MIMO system has dimensions of 58 × 58 × 0.787 mm3 with a maximum realized gain of 5.3 dBi. The antenna's performance in terms of MIMO parameters like Envelope Correlation Coefficient (ECC) and Diversity Gain (DG) is within satisfactory limits for medical imaging applications. Time domain analysis also yields positive results, allowing its integration into a breast phantom tumor detection simulation. The simulation and measurement results demonstrate excellent agreement, making this antenna a promising candidate for microwave imaging and biomedical applications.

Dual-Band (28/38 GHz) Compact MIMO Antenna System for Millimeter-Wave Applications

The present work proposes a novel design of a dual-band-printed antenna for operation at the millimeter-wave frequencies 28 and 38 GHz that are utilized for the modern and future generations of mobile communications. The antenna is composed of two radiating elements. The first element is the main patch that is fed through a microstrip line with inset feed, and the second element is a parasitic element that is fed through capacitive coupling with the main patch. The design parameters of the proposed antenna are optimized through a complete parametric study to give excellent impedance matching at 28 GHz over the band 27.7–28.3 GHz and at 38 GHz over the band 37.7–38.3 GHz. The surface current distributions at the two operational frequencies are investigated. The designed antenna is used to construct a four-port efficient multi–input–multi–output (MIMO) system. The MIMO system performance is investigated regarding the envelope correlation coefficient (ECC), diversity gain (DG), and the channel capacity loss (CCL) showing very good performance. The single-element antenna and the MIMO are fabricated and experimentally evaluated showing excellent impedance matching over the lower and higher frequency bands, which come in agreement with the simulation results. It is shown that the antenna produces maximum gain of 7.4 and 8.1 dBi at 28 and 38 GHz, respectively. The average radiation efficiencies of the proposed antenna are 88% and 88.8% over the lower and higher frequency bands, respectively. In addition, the coupling coefficients between the MIMO antenna systems are measured experimentally showing very low coupling values resulting in an efficient MIMO system that is suitable for future millimeter-wave (mm-wave) applications.

Neural correlation of speech envelope tracking for background noise in normal hearing.

Everyday speech communication often occurs in environments with background noise, and the impact of noise on speech recognition can vary depending on factors such as noise type, noise intensity, and the listener's hearing ability. However, the extent to which neural mechanisms in speech understanding are influenced by different types and levels of noise remains unknown. This study aims to investigate whether individuals exhibit distinct neural responses and attention strategies depending on noise conditions. We recorded electroencephalography (EEG) data from 20 participants with normal hearing (13 males) and evaluated both neural tracking of speech envelopes and behavioral performance in speech understanding in the presence of varying types of background noise. Participants engaged in an EEG experiment consisting of two separate sessions. The first session involved listening to a 12-min story presented binaurally without any background noise. In the second session, speech understanding scores were measured using matrix sentences presented under speech-shaped noise (SSN) and Story noise background noise conditions at noise levels corresponding to sentence recognitions score (SRS). We observed differences in neural envelope correlation depending on noise type but not on its level. Interestingly, the impact of noise type on the variation in envelope tracking was more significant among participants with higher speech perception scores, while those with lower scores exhibited similarities in envelope correlation regardless of the noise condition. The findings suggest that even individuals with normal hearing could adopt different strategies to understand speech in challenging listening environments, depending on the type of noise.

Design of High-Gain and Low-Mutual-Coupling Multiple-Input–Multiple-Output Antennas Based on PRS for 28 GHz Applications

In this paper, a high-gain and low-mutual-coupling four-port Multiple Input Multiple Output (MIMO) antenna based on a Partially Reflective Surface (PRS) for 28 GHz applications is proposed. The antenna radiator is a circular-shaped patch with a circular slot and a pair of vias to secure a wide bandwidth ranging from 24.29 GHz to 28.45 GHz (15.77%). The targeted band has been allocated for several countries such as Korea, Europe, the United States, China, and Japan. The optimized antenna offers a peak gain of 8.77 dBi at 24.29 GHz with a gain of 6.78 dBi. A novel PRS is designed and loaded on the antenna for broadband and high-gain characteristics. With the PRS, the antenna offers a wide bandwidth from 23.67 GHz to 29 GHz (21%), and the gain is improved up to 11.4 dBi, showing an overall increase of about 3 dBi. A 2 × 2 MIMO system is designed using the single-element antenna, which offers a bandwidth of 23.5 to 29 GHz (20%), and a maximum gain of 11.4 dBi. The MIMO antenna also exhibits a low mutual coupling of −35 dB along with a low Envelope Correlation Coefficient and Channel Capacity Loss, making it a suitable candidate for future compact-sized mmWave MIMO systems.

Quad-Element MIMO Antenna System Using Half-Cut Miniaturized UWB Antenna for IoT-Based Smart Home Digital Entertainment Network

This work presents a miniaturized quad-element multi-input multi-output (MIMO) antenna with low mutual coupling, inherent isolation, and easy upgradability for an Internet of Things (IoT) based high-speed smart digital entertainment network using ultra-wideband (UWB) technology. Ultra Wideband (UWB) technology is anticipated to play a significant role in the future IoT based smart systems due to its ability to provide high precision location information, low power consumption, high data rates and secure communication. An elliptical quadrant-shaped radiator with a C-shaped protuberant ground plane is conceptualized as a quasi-monopole UWB antenna following the half-cut miniaturization approach with very compact dimensions of 18W11 mm2. The elliptical quadrant radiator in combination with C-shaped ground plane introduces multi-resonance characteristic in addition to providing better impedance matching with miniaturization and inherent high isolation for MIMO configuration. The single element antenna is then organized in an orthogonal arrangement with an edge-to-edge distance of 5 mm to develop a quad-element MIMO antenna system. The MIMO antenna structure realizes a wide bandwidth of 3.14-11.23 GHz (center frequency at 7.19 GHz), peak gain of 7.2 dBi, and radiation efficiency of above 60% with good isolation (>-20 dB) between the adjacent elements without employing any dedicated decoupling structure. The diversity performances of the proposed MIMO antenna are relatively good, with a very low envelope correlation coefficient (ECC) of less than 0.35 and diversity gain (DG) nearly at 10. Further, the total active reflection coefficient (TARC) <-10 dB and channel capacity loss (CCL) <0.4 bit/s/Hz, parameters are witnessed to be within acceptable limits. The simulated and measured results agree well, testifying that the proposed four-element MIMO antenna is suitable for UWB applications.

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.

Miniaturized and high gain circularly slotted 4×4 MIMO antenna with diversity performance analysis for 5G/Wi-Fi/WLAN wireless communication applications

A miniaturized with a high gain four port Multiple-Input Multiple-Output (MIMO) is presented in the manuscript. The presented design contains four radiating patch elements with a Defected Ground Structure (DGS). The shape of the radiating element is identified after the analysis of three stages. The design optimization is performed by changing the diameter of the circle loaded in the patch region and changing the length of the ground layer. The design is investigated for L, S, C, and X frequency band regions. The structure is designed using flame-retardant glass-reinforced epoxy laminate material (FR4) substrate material. The physical size of the four-port structure is 78x50 mm2. Three resonating frequency bands are observed at 2.02 GHz, 5.87 GHz and 11.19 GHz. The structure provides minimum return loss of −10.27 dB, −18.51 dB and −18.59 dB. The proposed design achieves a peak bandwidth of 3.94 GHz, and a maximum gain of 10.03 dBi, Various diversity parameters, including Total active reflection coefficient (TARC), Envelope Correlation Coefficient (ECC), mean effective gain (MEG), Diversity Gain (DG), and channel capacity loss (CCL), have been thoroughly analyzed. The measured and simulated outcomes are compared and analyzed. All performance indicators meet the allowed limits, demonstrating the suitability of the design for 5G, Wi-Fi and WLAN wireless communication applications.

Two closely spaced microstrip patches with high isolation for full-duplex/MIMO applications.

This paper shows an effective method to significantly enhance the isolation of a closely spaced two-port patch antenna, which can be deployed for full-duplex transceivers as well as multiple-input-multiple-output (MIMO) systems. Two rectangular microstrip patches are arranged in the E-plane configuration. To achieve high isolation, a grounded stub is positioned between the radiating patches. For validation of the proposed concept, an antenna prototype is fabricated for measurements. The measured data demonstrates that the port-to-port mutual coupling can be suppressed to -50 dB, which is useful in self-interference cancellation for full-duplex communication systems. Compared with the coupled design, the isolation is significantly enhanced by 43 dB with an inter-element spacing of 0.034λc, where λc is a free-space wavelength at the center operating frequency. Regarding MIMO metrics, the antenna also shows good MIMO diversity performance based on an envelope correlation coefficient and a diversity gain.

Test-retest reliability of the human connectome: An OPM-MEG study

Abstract Magnetoencephalography with optically pumped magnetometers (OPM-MEG) offers a new way to record electrophysiological brain function, with significant advantages over conventional MEG, including adaptability to head shape/size, free movement during scanning, increased signal amplitude, and no reliance on cryogenics. However, OPM-MEG remains in its infancy, with significant questions to be answered regarding the optimal system design. Here, we present an open-source dataset acquired using a newly constructed OPM-MEG system with a triaxial sensor design, 168 channels, OPM-optimised magnetic shielding, and active background field control. We measure the test-retest reliability of the human connectome, which was computed using amplitude envelope correlation to measure whole-brain (parcellated) functional connectivity, in 10 individuals while they watch a 600 s move clip. Our results show high repeatability between experimental runs at the group level, with a correlation coefficient of 0.81 in the θ, 0.93 in α, and 0.94 in β frequency ranges. At the individual subject level, we found marked differences between individuals, but high within-subject robustness (correlations of 0.56 ± 0.25, 0.72 ± 0.15, and 0.78 ± 0.13 in α, θ, and β respectively). These results compare well to previous findings using conventional MEG and show that OPM-MEG is a viable way to robustly characterise connectivity.

A dual operating (27/38 GHz) high performance 2 × 4 MIMO antenna array for 5G new radio applications

This article presents an unique configuration of Multiple-Input Multiple-Output (MIMO) antenna array for functioning at 27/38 GHz millimeter-wave 5G new radio (NR) frequency bands applications. The suggested antenna is constructed with four MIMO elements, containing total of eight identical patches arranged in a 2 × 4 array configuration. The array also includes a separate non-connected rectangular ground plane with an overall dimension of 32.4 × 32.8 × 0.8 mm3. The single radiating patch elements are designed using spline resonator with H-shaped structures. The prototype model is realized using low cost FR-4 substrate and the obtained measurement results validate the analyzed simulated results. The suggested MIMO array antenna offers dual band operation with an impedance bandwidth of 8400 MHz covering 22 to 30.4 GHz and 8500 MHz ranging from 36.1 to 44.6 GHz. The proposed antenna achieves a peak gain of 8.75 dBi when operating at 27 GHz and 18.59 dBi at 38.1 GHz. Furthermore, it shows circular polarization characteristics by offering the axial ratio values significantly lower than 3 dB at 27 GHz and 38.1 GHz frequency bands. Additionally, the results indicate the favourable values of the diversity performance parameters with reference to Mean effective gain (MEG), Envelope correlation coefficient (ECC), Diversity gain (DG), Total active reflection coefficient (TARC), and Channel capacity loss (CCL). Moreover, it demonstrates high isolation (<−20 dB) within the desired bandwidth. These superior characteristics make it compatible for 5G NR frequency bands N257(26.5-29.5 GHz), N258 (24.5-27.5 GHz), N259 (39.5-43.5 GHz) and N260 (37-40 GHz), enabling its use in various countries including the China, European Union, Sweden, Korea, Japan, United States of America, Canada and Australia.

Quasi-binomial series-fed array for performance improvement of millimeter-wave antenna for 5G MIMO applications

A quad-port MIMO antenna based on a quasi-binomial series-fed array is presented in this paper for n257 and n258 millimeter-wave applications with an investigation of additional loaded patches on performance enhancement of the conventional binomial series-fed array. The single element of the proposed MIMO is a 3 × 3 element planar binomial series-fed array whose width of the radiating elements is tapered to achieve the binomial distribution. From both simulated and tested results, it is observed that a wider bandwidth (S11 < –10 dB of 21.78 %), high peak gain (12.4 dBi), and high radiation efficiency (92 %) with side lobe level (SLL) reduction of more than 9 dB are achieved by additional loaded patches. This design approach does not only offer wider bandwidth, low SLL, and gain increment, but also ensures the excellent diversity performances of the very closely spaced (0.116λ) MIMO antenna, without utilizing any additional decoupling structure. The proposed MIMO antenna system offers impedance bandwidth (S11 < − 10 dB) from 24.6 GHz to 30.59 GHz, isolation > 27 dB, envelope correlation coefficient < 0.0002, diversity gain > 9.99 dB, and mean effective gain between –4 dB and –8 dB. Owing to its performance attributes, the proposed antenna is an excellent choice for 5G millimeter-wave communication devices, including but not limited to enormous IoT, smart cities, and virtual reality.

High Performance Antenna System in MIMO Configuration for 5G Wireless Communications Over Sub‐6 GHz Spectrum

AbstractThis paper presents a high‐performance multiple input and multiple output (MIMO) antenna comprising 2 × 2 configuration of radiating elements that is designed for sub‐6 GHz applications. The proposed MIMO antenna employs four identical radiating elements. High isolation between the radiating elements and therefore reduced mutual coupling is achieved by spatially arranging the radiating elements in an orthogonal configuration. Also, a novel frequency selective surface (FSS) was employed to increase the gain of the MIMO antenna over a wide bandwidth from 3 to 6 GHz. This was achieved by locating the FSS above the antenna at a certain height. The FSS essentially enhanced the antenna's directivity, reduced back lobe radiation and mutual coupling. The antenna was fabricated on a standard Rogers RT Duroid 5880 dielectric substrate with a 0.8 mm thickness. The overall dimension of the MIMO antenna is 50 × 50 × 12.5 mm3 and it operates from 3.8 to 6 GHz, which corresponds to a fractional bandwidth of 41%. The proposed MIMO antenna has a measured peak gain of 4.8 dBi and inter radiation element isolation &gt;20 dB. Its envelope correlation coefficient is &lt;0.1 and diversity gain &gt;9.9 (dB). These characteristics make the proposed MIMO antenna system suitable for 5G communication systems.

Comparing individual and group-level simulated neurophysiological brain connectivity using the Jansen and Rit neural mass model.

Computational models are often used to assess how functional connectivity (FC) patterns emerge from neuronal population dynamics and anatomical brain connections. It remains unclear whether the commonly used group-averaged data can predict individual FC patterns. The Jansen and Rit neural mass model was employed, where masses were coupled using individual structural connectivity (SC). Simulated FC was correlated to individual magnetoencephalography-derived empirical FC. FC was estimated using phase-based (phase lag index (PLI), phase locking value (PLV)), and amplitude-based (amplitude envelope correlation (AEC)) metrics to analyze their goodness of fit for individual predictions. Individual FC predictions were compared against group-averaged FC predictions, and we tested whether SC of a different participant could equally well predict participants' FC patterns. The AEC provided a better match between individually simulated and empirical FC than phase-based metrics. Correlations between simulated and empirical FC were higher using individual SC compared to group-averaged SC. Using SC from other participants resulted in similar correlations between simulated and empirical FC compared to using participants' own SC. This work underlines the added value of FC simulations using individual instead of group-averaged SC for this particular computational model and could aid in a better understanding of mechanisms underlying individual functional network trajectories.

Design and Performance Analysis of 28 GHz two-port MIMO Rectangular Microstrip Patch Antenna Array for 5G Applications

A rectangular microstrip patch antenna array with two ports, designed for operation in the mm-wave band at 28 GHz for 5G applications, has been developed to exhibit superior gain and efficiency. This paper introduces a 12-element array activated by a feed network utilizing a T-junction power combiner/divider. The array elements consist of rectangular patch antennas inserted throughout the structure. The designed array antenna exhibited a measured impedance bandwidth of 1.42 GHz. The simulated findings indicate that the antenna achieved a favorable impedance match, with isolation levels below -22 dB throughout the frequency range. The whole substrate board dimensions were 19.99 × 26.968 × 0.254 mm3. The array is positioned on the substrate material known as Rogers RT5880, resulting in a consistent and reliable radiation pattern. The CST MWS software is employed to model and simulate the microstrip patch array antenna. CST MWS is an electromagnetic simulator utilizing the Finite Integration in Technique (FIT) methodology to model and analyze full-wave electromagnetic phenomena accurately. The realized gain of 15 dBi has been reached for the combined array, whereas the individual arrays have a realized gain of 12.3 dBi. The calculated overall efficiency is roughly -0.5 decibels. The antenna array under consideration has demonstrated favorable multiple-input multiple-output (MIMO) capabilities, as evidenced by an envelope correlation coefficient (ECC) of less than 0.1.

A High-Frequency Planar-Configured Millimeter-Wave MIMO Antenna for Fifth-Generation NR Operations

This article presents a simple planar millimeter-wave (mm-wave) multiple input multiple output (MIMO) antenna with four closely spaced radiating elements. The antenna is intended to enhance the bandwidth for 5G new radio (NR) applications and also cover the industrial Ka-band (26.5-40 GHz), Q-band (30-50 GHz), and U-band (40-60 GHz) frequency ranges. The antenna is designed using Rogers RT/duroid 5880 substrate with a size of 25 × 26 × 1.6 mm3. The proposed antenna consists of four identical radiating elements with two of them positioned in a linear configuration facing each other, while the other two elements are placed opposite to the first two, which improves isolation between the elements. Across the entire operating frequency range (26-60 GHz), the antenna demonstrated excellent performance, including 34 GHz wide bandwidth, high isolation of &gt;25 dB, nearly omnidirectional radiation patterns, high gain of 11.1 dB with a high radiation efficiency of 94%, low envelope correlation coefficient (ECC) of 0.0068, and high diversity gain (DG) of 9.967 dB. The simulated findings exhibit a strong positive correlation with the experimental results. The proposed MIMO antenna design is a promising solution for 5G NR applications.