Port MIMO Antenna Research Articles

Efficient High Gain Elliptically Polarized Phased MIMO Antenna

A phased MIMO antenna with a coaxial feed is designed to operate in the electromagnetic spectrum with the frequency range of 8 GHz to 12 GHz, which resonates at 9 GHz, is used in military and satellite communication. The ability of phased MIMO antennas to change the form and orientation of the radiation pattern without constantly moving the antenna is unique. The proposed approach can also improve radiation efficiency by maximizing array unit size. To validate the proposed method, an elliptical polarization phased antenna has been constructed as a planar array. A 2 to 2 planar dual polarized MIMO antenna is intended to improve the efficiency. The obtained return loss for 2x2 planar MIMO is -19.34 dB. The proposed 2x2 MIMO antenna is projected on a teflon material with dielectric constant of 2.25 and the thickness of the substrate is 7mm. The efficiency for two port MIMO antenna is 97.7%.

Performance Analysis of MIMO Antenna Design with High Isolation Techniques for 5 G Wireless Systems

This paper investigates different approaches for achieving isolation in a MIMO antenna design. It provides an in-depth comparison of these techniques, analyzing their advantages and disadvantages. The challenges of obtaining sufficient isolation in modern MIMO antenna design are discussed, and various isolation methods developed for the MIMO design are examined. The study introduces a compact 28 GHz 4-port MIMO antenna design, which is placed on a Rogers RT/Duroid 5880 substrate. The design includes a rectangular patch with semicircles at the ends and dual slots etched from it. A partial ground plane is integrated into the antenna to achieve an operating frequency range from 22 to 29 GHz, centered at 24 GHz. To reduce mutual coupling between elements, four elements are arranged orthogonally and four stubs are added at a specific frequency band to enhance isolation. The ground plane also incorporates a defected ground structure (DGS) to improve gain. To optimize the antenna’s bandwidth, a ground cut technique is used, resulting in a 0.7 GHz bandwidth enhancement at the cost of some isolation. The antenna operates in the range of 22.5– 29.1 GHz, with a peak gain of 6.39 dBi. Each technique is compared based on parameters such as S-parameters (return loss or reflection coefficient), voltage standing wave ratio (VSWR), isolation level, and peak gain. Simulated results are shown for each of the techniques to compare their performance by using Ansys HFSS simulations which confirm that the designed antenna meets the target band requirements and could be used in 5 G communications.

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.

Sickle-shaped high gain and low profile based four port MIMO antenna for 5G and aeronautical mobile communication

The construction of the four-port MIMO antenna in the form of a sickle is provided in the article. Initially, the single port element is designed and optimized. Next, a structure with two ports is created, and lastly, a design with four ports is completed. This process is repeated until the design is optimized. Three types of parametric analysis are considered, including variations in length, widths of sickle-shaped patches, and varying sizes of DGS. The frequency range of 2–8 GHz is used for structural investigation. The − 18.77 dB of return loss was observed at 3.825 GHz for a single-element structure. The optimized one-port structure provides a return loss of − 19.79 dB at 3.825 GHz. The port design offers a bandwidth of 0.71 GHz (3.515–4.225). The four-port design represents two bands that are observed at 3 GHz and 5.43 GHz. Both bands provide the return loss at respectively − 19.79 dB and − 20.53 dB with bandwidths of 1.375 GHz (2.14–3.515) and 0.25 GHz (5.335–5.585). The healthy isolation among both transmittance and reflectance response is achieved. The low-profile material was used to create the design that was presented. The article includes a comparison of the findings that were measured and those that were simulated. The four-port design that has been shown offers a total gain of 15.93 dB, a peak co-polar value of 5.46 dB, a minimum return loss of − 20.53 dB, a peak field distribution of 46.43 A/m and a maximum bandwidth of 1.375 GHz. The values for all diversity parameters like ECC are near zero, the Negative value of TARC, Near to zero MEG, DG is almost 10 dB, and a zero value of CCL is achieved. All diversity parameter performance is within the allowable range. The design is well suited for 5G and aeronautical mobile communication applications.

Compact dual band 4-port MIMO antenna for 5G-sub 6 GHz/N38/N41/N90 and WLAN frequency bands

In this investigation, a dual-band 4 port MIMO antenna is designed, fabricated and measured. The MIMO design consists of perturbed hexagonal patch along its periphery on the top of the substrate and the connected ground plane on the bottom. The MIMO design has an overall dimension of 50 × 50 × 0.8 mm3. The proposed antenna structure demonstrates the dual frequency band of 2.47–3.38 GHz and 4.94–7.24 GHz, respectively covering the 5G sub-6 GHz/WLAN/HiperLAN band applications. Moreover, the radiation efficiency, gain and far-field patterns are also presented across both the operating bands. The antenna diversity parameters which include ECC, DG, MEG, CCL and TARC are studied and found excellent for the MIMO antenna implementation. The channel loss of the proposed 4 × 4 MIMO antenna is calculated and found 21.54 b/s/Hz at SNR of 20 dB. The proposed design is modeled in CST Microwave Studio and the results are compared with the fabricated prototype antenna for the practical implementations.

Circularly polarized printed dual port MIMO antenna with polarization diversity optimized by machine learning approach for 5G NR n77/n78 frequency band applications

In this communication, a planar dual port multiple input multiple output antenna of size 1.2λ0 × 0.6λ0 × 0.008λ0 with LHCP/RHCP features is reported for the fifth-generation new radio n77/n78 sub-6 GHz wireless applications band. The single unit of the proposed design consists of a modified L-shape rectangular radiator with Z-shape slot loaded DGS. The defected ground structure is optimized through machine learning algorithms to achieve the maximum ARBW (output) by Right Shifting (RS) and left shifting (LS) the DGS and obtaining input features. The performance metric for ANN with ADAM optimizer was found to be optimal with MSE and R2 of 0.99 and 0.82, respectively. ANNs can leverage gradient information to guide the optimization process. This enables faster convergence towards optimal solutions compared to popular GAs and PSO, which are often gradient-free optimization methods. The MIMO configuration is achieved by creating a mirror image of the single unit about the x-axis. The salient features of the proposed design are (a) Impedance bandwidth (IBW) of 3.0–4.2 GHz covering the n77/n78 band, (b) 3-dB axial ratio bandwidth (ARBW) of the 2.6–3.9 GHz (c) Port-1 is generating RHCP while Port-2 is generating LHCP, results in polarization diversity. Different diversity performance parameters (ECC < 0.005, DG ~ 9.99 dB, and MEG < 3 dB) are in the optimum range confirming the proposed configuration as a suitable design for a MIMO radiator.

Self-decoupled tri band MIMO antenna operating over ISM, WLAN and C-band for 5G applications

For ISM, WLAN, and C-band applications, a multiple-stub loaded CPW feed tri-band antenna is presented in this study. The suggested antenna uses Rogers RT/Duroid 5880 substrate material with a 0.79 mm thickness. The antenna has a straightforward design, measures just 33 mm × 20 mm, and provides broad performance with excellent gain. A 4-port MIMO arrangement is subsequently used to fulfill the demands of upcoming 5G and 6G devices. The MIMO antenna contains little space between elements and offers a good value of < –30 dB isolation. The overall size of a 4-port MIMO antenna is MW × ML × H = 60 mm × 60 mm × 0.79 mm and offers a minimum value of ECC <0.0001. Besides ECC, the MIMO antenna also offers good results in terms of DG, CCL, and MEG. To validate the findings of the simulation, a hardware prototype of the suggested antenna is created. It is clear that the results from simulations and measurements coincide well. The proposed antenna was created with the aid of the software tool Ansoft HFSSv9. Also, the proposed work is evaluated against previously published material. The suggested antenna has a small size, a simple geometry, a wideband, high gain, and a good value for the MIMO parameters, according to the results and comparisons of the proposed work (in terms of ECC, DG, CCL, and MEG), and low spacing between elements, which makes it a promising candidate for future 5G devices operating over ISM, WLAN, and C–band applications.

4-Port MIMO antenna with novel isolator conducting structure for sub-1 GHz/sub-6 GHz and RF-energy harvesting applications

A 4-port MIMO antenna with a novel isolator structure for sub-1GHz/sub-6GHz and RF-energy harvesting applications is presented in this research. The proposed antenna is investigated systematically at 2.6 GHz design frequency with four distinct stages: STEP-1, STEP-2, STEP-3 and STEP-4 and an optimal design (STEP-4: mm3) is chosen for further study. A unique isolation structure was developed between two identical elements separated by , resulting an improved isolation of greater than 14 dB at 0.9 GHz and greater than 18 dB at 2.6 GHz is obtained. The suggested antenna resonates at 900 MHz-simulated & measured and 2.6 GHz-simulated & 2.8 GHz-measured with simulated fractional bandwidth/resonating band of 24.6%/0.778–1 GHz & 20.7%/2.4–2.94 GHz and a measured fractional bandwidth/resonating band of 17.8%/0.83–0.99 GHz & 21%/2.41–3 GHz at lower and upper resonating frequencies respectively. A peak gain of 1.5 dB at 900 MHz and 4.2 dB at 2.8 GHz has been obtained. The SAR values of less than 0.5 and 1.6 W/kg and radiation efficiencies of 74.7% and 90% at 900 MHz and 2.8 GHz were obtained, respectively. The suggested antenna's MIMO performance is simulated using electromagnetic tool HFSS in terms of ECC, DG, TARC, MEG and CCL, and the obtained results are experimentally verified. Further, the proposed antenna is tested for harvesting applications wherein 9.5 mW of harvested power, 76.45% power conversion efficiency (PCE), 4V harvested voltage, current 2.4mA and 12.46 mW Friis equation output at 915 MHz and 26.98 mW of harvested power, 69.5% power conversion efficiency, 5V harvested voltage, current 5.4 mA and 38.8 mW Friis equation output at 2.5 GHz are recorded.

Design of a highly-isolated, high-gain, compact 4-port MIMO antenna loaded with CSRR and DGS for millimeter wave 5G communications

In this paper, a low-profile, compact, high-gain antenna solution for four-port mm-wave broadband MIMO communication in a 5G environment is presented. The proposed antenna design consists of two rectangular patches connected through a corporate feed network and two quarter-wavelength square-shaped CSRRs on the ground plane. The overall size of the proposed four-port orthogonal MIMO configuration is 28.3 mm × 28.3 mm × 0.508 mm. The antenna operates on the 5G frequency bands of n257, n258, and n261 with an effective bandwidth of 3.9 GHz covering the range of 26.5 GHz to 30.4 GHz. The suggested MIMO antenna attained a peak gain of 11 dBi and radiation efficiency of 96% at 28 GHz resonating frequency. The MIMO configuration utilized DGS to minimize near-field coupling current at the ground plane, resulting in high port-to-port isolation of >40 dB, and co-pol to X-pol isolation improvements of >9 dB and >19 dB in the boresight direction of E-plane and H-plane at 28 GHz resonating frequency. The antenna’s superior diversity performance is supported by several performance metrics, including ECC(<0.0001), DG(>9.999 dB), CCL(<0.12 bits/s/Hz), MEG (< −3 dB), and TARC. Moreover, the linear transmission property of the proposed MIMO antenna is also validated through the variation of group delay (<0.6 ns) over operating frequency bands in the far-field region.

Design and Analysis of Dual Narrow Band MIMO (DNB-MIMO) Antenna for IoT Applications

A compact DNB-MIMO antenna design and analysis for IoT application was proposed. The antennaradiator consists of 2 L-shaaped quarter-wavelengths and inverted 7-shaped radiators with a microstrip feed line, and partial ground plane with a size of 32 × 15 mm2. This antenna achieves a higher quality factor (Q &gt; 10) and narrow band impedance matching at the central frequencies of 1.8 GHz and 2.4 GHz bands with approximately 8.2% and 6.2% bandwidth respectively. The suitability of the designed antenna for IoT applications is verified through the hosting device model. The proposed 4-port MIMO antenna has an overall size of 60 × 60 ×1.6 mm3, and it is printed on an FR4 substrate. The diversity add comma such as ECC, DG, TARC, MEG, and CCL, are calculated and there values are &lt; 0.19, 9.85 dB, &lt; -25 dB, &lt; -6 dB, &lt; 0.19 bits/Hz/s, respectively, within the limits. The proposed antenna is integrated with the Zigbee module (lowercase) to analyze the performance for IoT applications at 2.4 GHz

A crossed-polarized four port MIMO antenna for UWB communication

This paper presents a compact, crossed-polarized, ultra-wideband (UWB) four-ports multiple-input-multiple-output (MIMO) printed antenna. The proposed antenna is constructed from four microstrip circular patch elements fed by a 50-Ω microstrip line. Two metamaterial cell elements, in the form of a rectangular concentric double split ring resonator (SRR), are placed at the upper plane of the substrates for bandwidth improvement and isolation enhancement. The ultra-wideband frequency response is achieved using a defective ground plane. Surface current flow between the antenna's four elements is limited to ensure maximum isolation. The four-port MIMO system is designed with orthogonal antenna elements orientation on an FR4 substrate with a loss tangent of 0.02 and an overall size of 30 mm × 30 mm × 1.6 mm. Such orientation resulted in less than −17dB port-to-port isolation and an impedance bandwidth of 148% (3.1–12 GHz). The proposed UWB-MIMO antenna achieved a maximum realized gain of 6.2dBi with an efficiency of 87%. The measured and simulated results are in good agreement over the operating frequency band (3.1–12 GHz). The results also provide overall good diversity performance with the TARC < −10 dB, ECC < 0.001, DG > 9.9, MEG < −3 dB and CCL <0.1. The proposed antenna is well-suited for applications in WLAN, WIMAX and GPRs.

A Micro 4-port THz MIMO antenna for nano communication networks

This paper proposes a micro nature inspired UWB 4-port MIMO antenna design with dimensions of 45μm × 45μmăoperating from (2.38–11.18) THz and 130% impedance bandwidth realised on a 2μm thick polyamide substrate. Each radiator is made by superimposing self-similar elliptic structures to create a palmate leaf-like pattern that ensures wideband response. The ground topology is made up of semi-elliptic orthogonal reflectors connected to a center-fed annular circle with rotationally symmetrical parasitic stubs that operate as an isolator, resonator, and neutralizer. The antenna elements are ordered orthogonally with an inter-element distance of d0 = 0.05λ0 (λ0 is the lowest working wavelength at 2.38 THz) and an inter-element port isolation distance of d0 = 0.05λ0. The parasitic stub inclusion increases the lower/higher band 10-dB impedance matching response, and the proposed ground structure has good isolation coefficients (18−22)dB. An equivalent circuit model with R-L-C lumped elements was modelled and simulated to validate. In both indoor and outdoor propagation environments, the MIMO diversity parameters (Envelope channel coefficient (ECC), Total active reflection coefficient (TARC), Diversity gain (DG), Channel capacity loss (CCL), Mean effective gain (MEG), and Multiplexing efficiency) show good characteristics to leverage. The suggested MIMO antenna can be employed for THz band and molecular/nano communication networks owing to its radiation performances (realised gain of > 8 dBi with > 60% radiation efficiency).

Flexible interconnected 4-port MIMO antenna for sub-6 GHz 5G and X band applications

A flexible 4-port 4-element interconnected MIMO antenna is proposed for Sub-6 GHz 5G and X-band applications. The 4-element structure attains a low profile of 0.612λ2 (at 3.34 GHz) through careful placement of antenna elements. The elementary antenna top side is formed of an inverted E and inverted L-shaped conductive structure attached to both sides of the central feed line. Two hollow tilted square-shaped assemblies are added horizontally with the inverted L for performance enhancement. The bottom plane consists of a truncated ground with a vertical stub on the side for achieving wideband performance. The MIMO configuration along with polarization diversity is attained by positioning the elementary antenna symmetrically in a sequential rotational manner. The interconnection between ground planes is ensured by placing an I-shaped strip which is further modified by adding a slotted rectangular stub on the central vertical line for better isolation. The flexible antenna demonstrated minimum efficiency and maximum gain of 70% and 4 dBi, respectively in addition to accomplishing a bandwidth of (40%) 3.34–5.01 GHz and (3.31%) 8.9–9.2 GHz while satisfying the MIMO diversity performance in terms of envelope correlation coefficient (ECC) < 0.17. Finally, the antenna performance in terms of S-parameters and MIMO diversity parameters are tested by bending the antenna along the X and Y axis that demonstrated decent performance thus making the MIMO antenna worthy for its use in Sub-6 GHz 5G and X Band Applications with tight space requirements.

Compact CPW fed Four Port MIMO Antenna for UWB applications with Wi-Fi/ISM/WLAN Band Notch Characteristics

A compact UWB with WLAN notch-based four-element CPW fed MIMO/diversity antenna is presented in this paper. Multiple elements facilitate the design to transmit and receive the signal from all directions enhancing the channel capacity and diversity performance. The inverted L-shaped stub attached to the ground enhances the impedance bandwidth (10 dB) and provides the UWB response. Plus and cross-shaped decoupling structure is accomplished to diminish the surface current and enhances the isolation between antenna elements and it is more than 20.2 dB from port-1 to port-4 without affecting the impedance bandwidth and radiation pattern. A complimentary split ring resonator (CSRR) in the radiator is utilized to eliminate the Wi-Fi/WLAN band. The |S11| of UWB MIMO antenna varies from 3.26 GHz to 14 GHz which can be utilized in portable, Radar, Satellite, and wireless applications. The simple decoupling structure is used to correlate and isolate the antenna elements, therefore acceptable ECC and CCL parameters are achieved.

A compact four port MIMO antenna for millimeterwave applications

A novel compact microstrip MIMO antenna with high isolation and low envelope correction coefficient has been proposed and presented in this paper. The proposed antenna is compact in size with 3.22x4.86 mm2, operating over the frequency band of 60GHz. The MIMO antennas have been designed andsimulated using electromagnetic design and verification platformIE3DTM. Two ports MIMO antenna with the size of 3.22x1.93 mm2 resonates at 58.1 GHz covering a band of 57-59.3 GHz, with the bandwidth of 2.3 GHz, gain of 5.2 dBi, and directivity of 8.67 dBi. It also provides aninput reflection coefficient of -18.41 dB with isolation of -19.98 dB. Proposed four port MIMO antenna resonates at 58 GHz covering a range of 56.9 GHz to 59.2 GHz, with a bandwidth of 2.3 GHz, gain of 5.44 dBi, and the directivity of 9.75dBi. It provides goodisolationranging from -19 dB to -30 dB with input reflection coefficient of -18.09 dB. The envelope correlation coefficient (ECC) of the proposed four-port MIMO antenna is below 0.06 in far-field radiation characteristics. The proposed MIMO antenna has been analyzed for its diversity performance in terms of ECC, mean effective gain, and diversity gain.

A novel approach for low mutual coupling and ultra-compact Two Port MIMO antenna development for UWB wireless application

In this paper, a novel MIMO antenna operating in the UWB frequency band is presented. The proposed new antenna shape is derived from the conventional circular ring patch antenna having a partial ground plane. An array of three Quad-G Shaped Metamaterial structures was used between the antenna elements of the two-port MIMO antenna to expand the bandwidth in the lower frequency band of UWB application (below 5.567 GHz) and reduce the mutual coupling in such expanded band. The proposed MIMO antenna operates over a bandwidth of 8GHz from 4 GHz to 12 GHz. Over the entire bandwidth, the mutual coupling between antenna elements is less than -19.0 dB with an inter-element separation (sep) of λ/6 mm. The overall optimized dimensions of the proposed antenna are 0.34λ×0.22λ×0.021λ for a free-space wavelength, λ, calculated at 4GHz. The radiation pattern of the proposed MIMO antenna was analyzed using the Combined Results Technique (CRT) integrated into the CST microwave studio. The obtained peak radiation efficiency and gain are 83.0% and 5.57 dB respectively. The MIMO Performance metrics such as envelope correlation coefficient (ECC), diversity gain (DG), channel capacity loss (CCL), Mean Effective Gain (MEG), Total Active reflection Coefficient (TARC), and multiplexing efficiency are evaluated and compared to the standard values. The proposed antenna was compared to other antennas in the literature. It has been found that the key benefit of the present method was observed in achieving the highly miniaturized overall antenna dimension having good MIMO system performance metrics and better radiation characteristics. The proposed antenna was fabricated and measured. The measured and simulated values are found to be in good agreement.

Miniaturized four port MIMO antenna for automotive communications

Miniaturized four port MIMO antenna for automotive communications

4-port UWB MIMO antenna with bluetooth-LTE-WiMax band-rejection and vias-MCP loaded reflector with improved performance

In this article, a 4-port MIMO antenna of dimension 0.46λ0 × 0.46λ0 × 0.01λ0 (λ0 is the lowest operating wavelength at 2.08 GHz) is proposed. It consists of array of fractal radiators sorted orthogonally with 0.05λ0 edge-to-edge separation and contorted feeds perform as impedance transformer. A centered π-shaped inverted-L notch asserts rejection at bluetooth-LTE-WiMax band. The MIMO configuration has common ground plane with no decoupling topology provides an inter-elemental port isolation > 15 dB. There are four vias-Metallic conducting probes (vias-MCP) connected to antenna ground and reflector. The conducting probes enroute the near-field currents from radiators and neutralize into the loaded reflector, with isolation improved > 20 dB and antenna performances are enhanced. The reflector has dimension 0.58λ0 × 0.58λ0 fixed at Hair = 0.07λ0 (≈ 10 mm). The antenna operates from (2.08–10.4) GHz with band rejection at (2.27–3.62) GHz, asserts improved gain characteristics (7–9.57) dBi at pass band and −4 dBi at notched band. This new technique of vias-MCP in the proposed multi-port configuration mitigates mutual interaction of surface wave coupling on radiators, reduces near-field condensed currents and couplate the surface waves into the loaded reflector to improvise impedance matching and gain characteristics for UWB wireless communication systems.

Interconnected CPW Fed Flexible 4-Port MIMO Antenna for UWB, X, and Ku Band Applications

Interconnected CPW Fed Flexible 4-Port MIMO Antenna for UWB, X, and Ku Band Applications

Enhanced 4-Port MIMO Antenna Based on Electromagnetic Mutual Coupling Reduction Using CSRRs Metamaterials for Sub-6 GHz 5G Applications

Enhanced 4-Port MIMO Antenna Based on Electromagnetic Mutual Coupling Reduction Using CSRRs Metamaterials for Sub-6 GHz 5G Applications