Dual-band MIMO Research Articles

A Dual-Band Patch Antenna with Combined Self-Decoupling and Filtering Properties and Its Application in Dual/Squad-Band Two-Element MIMO Array.

This paper proposes a dual-band patch antenna with combined self-decoupling and filtering properties, designed to suppress mutual coupling between two antenna elements both within the same dual-band and across different dual-bands. Initially, a dual-band aperture-coupled filtering patch antenna is designed, featuring a forked short-circuited SIR feedline with a quarter-wavelength open-ended stub and a U-shaped patch with two U-slots, which generate three controllable radiation nulls while introducing two additional resonant modes. The design steps are also provided in detail. Subsequently, the low mutual coupling phenomenon of two vertically placed aperture-coupled patch antennas is investigated, successfully developing a high-isolated dual-band two-element MIMO array I. Furthermore, the other quad-band two-element MIMO array II is designed, which utilizes the filtering response to significantly reduce mutual coupling across four bands. Finally, a dual-band filtering patch antenna element and two two-element MIMO arrays are fabricated and measured. The measurements and simulations validate the antenna's low mutual coupling performance in multi-band MIMO arrays and demonstrate its strong potential for future wireless communication applications.

Dual-Band and Wideband Self-Decoupled MIMO Antennas With Four Hybrid Modes

Dual-Band and Wideband Self-Decoupled MIMO Antennas With Four Hybrid Modes

Design of a High Order Dual Band MIMO Antenna with Improved Isolation and Gain for Wireless Communications

Design of a High Order Dual Band MIMO Antenna with Improved Isolation and Gain for Wireless Communications

Four-port dual-band textile MIMO antenna for biomedical health monitoring systems: on-body mutual coupling reduction characterization

The paper outlines a methodology to diminish mutual coupling in 4-port dual-band MIMO textile antenna for biomedical applications. This antenna leverages MIMO technology and Wireless Body Area Network (WBAN) for operation in two distinct frequency bands at (3.5 & 2.45 GHz). The antenna is made up of four octagonal patch antennas, each having a bar and a split-ring (SR) slot with 47.2 × 31 mm2 dimensions for each patch. A hybrid mutual coupling (MC) approach was investigated with closely spaced patches (up to 0.05λ). Various bending setups have been selected along with flat case to examine the antennas’ resilience which demonstrate such agreement between measured and simulated findings. Furthermore, the MC is only −20 dB, the envelope correlation coefficient (ECC) is 0.001, and maximum peak measured gain of 5.2 dBi is achieved with lowest peak specific absorption rate (SAR) value. Even when bent at a 60° angle along with y-axis and x-axis, the antenna retains a decent gain of 1.861 dBi in the low frequency region and 5.479 dBi at high frequency band. Surprisingly, the antenna outperforms the attenuation produced by the lossy effects of the human body, indicating a favorable alignment between the modelled and observed findings.

A Low-Profile Pattern and Polarization Diversity Dual-Band MIMO Antenna with Full Azimuth Coverage for Indoor Access Points

A Low-Profile Pattern and Polarization Diversity Dual-Band MIMO Antenna with Full Azimuth Coverage for Indoor Access Points

Dual-band MIMO antenna design for enhanced 5G performance: simulation, implementation, and evaluation

Dual-band MIMO antenna design for enhanced 5G performance: simulation, implementation, and evaluation

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

A novel dual-band elliptical ring slot MIMO antenna with orthogonal circular polarization for 5G applications

This paper presents a dual-band 4-element multiple-input-multiple-output (MIMO) antenna featuring orthogonal circular polarization (CP) for Sub-6 GHz 5G applications. The single antenna combines a non-uniform width elliptical ring slot and a feed network, utilizing two L-shaped secondary feed lines to generate CP within the targeted frequency bands (3.55−3.80 GHz and 4.60−4.80 GHz). Using the single antenna as a unit antenna, a 4-element MIMO configuration is devised, employing a mirror technique for element placement to achieve orthogonal CP. This placement method effectively enhances coverage area and enlarges the 3-dB axial ratio bandwidth in the lower band (3.40–3.80 GHz). The common ground connections among elements are established via four strip lines. The antenna shows a good diversity performance considering the envelope correlation coefficient (ECC) result of less than 0.04 and isolation greater than 15 dB. The simulated gains of the MIMO antenna are 4 and 5 dBic in the respective bands. The single and MIMO antennas are fabricated, and the antennas’ performances are evaluated. A good agreement is observed between the measured and simulated results. The dual CP and diversity performances of the MIMO antenna make it more efficient for 5G wireless applications.

Ultra-Compact 4-Port MIMO Antenna with Defected Ground Structure and SAR Analysis for 28/38 GHz 5G Mobile Devices

To tackle the challenge of keeping 5G mobile devices compact while supporting millimeter-wave bands, we've created an ultra-compact 4-port dual-band MIMO antenna with a defected ground structure (DGS). This design minimizes mutual coupling and covers a broad frequency range. Built on a Rogers TMM4 substrate with dimensions of 17.76×17.76 mm2, the antenna includes four planar patch antennas positioned perpendicularly at the corners. Each antenna operates at 28/38 GHz and features a rectangular patch with four rectangular slots and a full ground plane. The patches are separated by 0.5 λo, with the DGS further reducing mutual coupling. Both simulations and measurements indicate a significant reduction in mutual coupling (−39 to −60 dB), improving ECC, TARC, MEG, and DG. Time-domain and SAR analyses confirm the antenna's efficiency and its suitability for 5G devices.

High gain dual-band circularly polarized two-port MIMO antenna with equivalent circuit for WiMAX/5G/C- and X-bands applications

Abstract A compact two-port novel geometry with microstrip fed wide slot equivalent circuit based dual-band MIMO antenna system of low specific absorption rate is presented. The proposed structure has two horizontal slotted patch with symmetrical chamfered at both corners, which are responsible for improving impedance bandwidth (IBW) and achieving wide axial ratio. The different cutting slots from the ground plane and vertical slot in MIMO antenna elements are responsible for enhancing isolation. The proposed antenna design covers −10 dB IBW ranging from 3.25 to 4.39 GHz and 6.74–8.41 GHz. This antenna radiates at 3.5 and 7.2 GHz with corresponding radiation efficiencies of 86.2 % and 92.32 %, isolation < ${< } $ −20.05 and < ${< } $ −29.71 dB, excellent peak gain 8.02 and 9.32 dB, while bandwidth of 1.14 GHz (29.84 %) and 1.67 GHz (22.05 %). Different diversity parameters for the proposed MIMO antenna have been obtained such as, envelope correlation coefficient < ${< } $ 0.0121 and < ${< } $ 0.0009, diversity gain nearly 9.87 and 9.99 dB, channel capacity loss < ${< } $ 0.0028 bits/s/Hz, and mean effective gain < ${< } $ −3 dB. The proposed work is printed on FR-4 epoxy substrate with overall electrical size of 0.29 λ 0 × 0.61 λ 0 × 0.018 λ 0 at 3.5 GHz. Moreover, the suggested work also exhibits circular polarization ranging from 3.24–4.38, 5.27–7.2, 7.6–8.1 and 8.2–8.41 GHz. Finally, experimental analysis was done and the tested results exhibit good agreement with simulated results. The proposed structure is a suitable candidate for WiMAX/C-band, satellite for X-band and 5G LTE band applications.

Enhanced smartphone connectivity: dual-band MIMO antenna with high isolation and low ECC

The research presents an eight-element dual-band modified T-shaped slot antenna array optimized for seamless integration into contemporary smartphones, addressing the burgeoning demands of 5G communication within the sub-6 GHz spectrum. Operating across two critical frequency bands spanning 3.37-3.61 GHz and 4.9-5.1 GHz, this advanced antenna system boasts impressive efficiency and performance metrics. Symmetrically arranged on the ground plane, each antenna element measures 20 × 11.8 mm2 (equivalent to 0.233 λ×0.138λ), with a notable design feature being the inclusion of section Dx, strategically positioned between the ground-mounted antennas to enhance isolation among radiating elements by effectively managing surface currents. Fabrication results showcase isolation levels surpassing -14 dB, with an Envelope Correlation Coefficient (ECC) lower than 0.05 in the lower frequency band and 0.02 in the higher band, indicating robust performance in mitigating mutual coupling effects. The antenna array exhibits exceptional efficiency ranging from 48.5% to 63.7%, coupled with a commendable channel capacity of 38.8 bps/Hz and a gain of 3.9 dBi, highlighting its suitability for integration into smartphone devices and its potential to advance the next generation of mobile communication technologies.

Dual-band MIMO antenna with low mutual coupling for 2.4/5.8 GHz communication and wearable technologies.

To satisfy the requirements of modern communication systems and wearables using 2.4/5.8 GHz band this paper presents a simple, compact, and dual-band solution. The antenna is extracted from a circular monopole by inserting various patches and stubs. The genetic algorithm is utilized to optimize the parameters and achieve the best possible results regarding bandwidth and gain. Afterward, a 2-port multiple-input-multiple-output (MIMO) configuration is created by positioning an identical second single element perpendicularly to the first one. The electrical size of the suggested MIMO configuration is 0.26 λL × 0.53 λL, where λL represents the free space wavelength at lower resonance of 2.45 GHz. The common ground technique is adopted to further reduce and achieve the accepted level of mutual coupling of the MIMO configuration. The presented MIMO antenna offers a low mutual coupling of < -27 dB with 0.2 envelope correlation coefficient (ECC). The antenna has a gain of around 6.2 dBi and 6.5 dBi at resonating frequencies of 2.45 GHz and 5.4 GHz. Furthermore, the specific absorption rate (SAR) analysis of the MIMO antenna offers a range inside of the standard values, showing its potential for On/Off body communications. The comparison with already published works shows that the proposed antenna achieves better results in either compact size or wide operational bandwidth along with low mutual coupling.

High Isolation of Dual-Band MIMO Microstrip Antenna with Vertical – Horizontal Configuration for 5G Communication System

High Isolation of Dual-Band MIMO Microstrip Antenna with Vertical – Horizontal Configuration for 5G Communication System

A dual-band MIMO PIFA antenna with a printed rectangular open-ended ring for 5G/WLAN mobile terminal

A dual-band 8 × 8 multiple-input-multiple-output (MIMO) PIFA antenna that operates in the sub-6 GHz spectrum for 5G and WLAN mobile terminals is presented. The eight elements of the MIMO antenna are formed by using an L-slotted PIFA antenna, an L-shaped parasitic element, and a 2D rectangular open-ended ring parasitic structure that is printed next to the L-shaped parasitic element. In this article, we first proposed an ultra-thick PIFA antenna element to work in the 3.4-3.8 GHz 5G band and the 5.15-5.85 GHz WLAN band, adopting a new method that can provide dual-band behavior with wide bandwidth. Then, the final antenna element is used to design an eight-port MIMO antenna system, and the results show good MIMO performance in terms of envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), and multiplexing efficiency (ME).

A Hybrid QOGWO-GPR Algorithm for Antenna Optimization

Optimization of antenna performance is a non-linear, multi-dimensional and complex issue, which entails a significant investment of time and labor. In this paper, a hybrid algorithm of quasi-opposition grey wolf optimization (QOGWO) and Gaussian process regression (GPR) model is proposed for antenna optimization. The QOGWO is prone to global optimality, high precision for complex problems, and fast convergence rate at the later stage. The GPR model can reduce time cost of antenna samples generation. After being optimized by the proposed approach, a stepped ultrawideband monopole antenna and a dual-band MIMO antenna for WLAN can achieve wider bandwidth and higher gain or isolation at low time cost, compared to other intelligent algorithms and published literatures.

Design of a dual-band wearable flexible MIMO antenna system for ISM band applications

Abstract This article proposes a dual-band (2.4/5.8 GHz) wearable MIMO antenna system that can be applied to the ISM band. The antenna element uses an improved coplanar waveguide feeding structure. The four-element antenna system achieves high isolation between antenna elements through the self-decoupling structure of the antenna element and the orthogonal placement. The use of a floating ground structure effectively suppresses back radiation. Through the combination of coplanar waveguide feeding and floating ground, the antenna not only has a low profile but also improves the front-to-back ratio of antenna radiation, reducing the SAR value. The antenna also uses felt as a flexible dielectric substrate and conductive cloth as a radiation element, making the antenna flexible.

CSRR backed compact two-port, dual-band MIMO antenna for mm-wave applications

CSRR backed compact two-port, dual-band MIMO antenna for mm-wave applications

Dual-Band Compact Six-Element Millimeter Wave MIMO Antenna: Design, Characterization, and Its Application for V2V Communication

Dual-Band Compact Six-Element Millimeter Wave MIMO Antenna: Design, Characterization, and Its Application for V2V Communication

Circular Polarized Dual-Band Wearable Screen-Printed MIMO Antenna Integrated With AMC for WBAN Communications

Circular Polarized Dual-Band Wearable Screen-Printed MIMO Antenna Integrated With AMC for WBAN Communications

Design of Dual Band MIMO Antenna with Rhombus Shape for Wireless Applications

Design of Dual Band MIMO Antenna with Rhombus Shape for Wireless Applications