A compact self-decoupling dual band MIMO antenna

Background. Previously, Many MIMO designs were presented for 4G applications. Out of stated 4G MIMO antennas, few designs presented are not suitable for use in mobile phones due to their large size as compared to the standard sizes of current generation mobile phones. The rest, Ceramic based mobile phone antenna and a multi-band MIMO antenna with PIFA structures have significant heights and non-planner structure which makes them unsuitable for mobile phones as they are getting thinner with advancement in technology. Some MIMO antennas were designed with simpler structure and suitable size but they do not have adequate bandwidth. Here there is a need to develop a MIMO system with an adequate bandwidth to cover all 2G, 3G and 4G bands as well as compact to be suitable for mobile communication.Objective. The purpose of the paper is to design a compact planner MIMO antenna Suitable for Mobile communication with enhanced gain and an enhanced bandwidth to cover all 2G, 3G and 4G bandsMethods.i. A monopole was designed with proper dimensions, which was designed to operate at focus recurrence of 1.8GHz. That covers the wide scope of data transfer capacity from 1.1 GHz to 2.7 GHz at -9 dB reference line. Then an inverted L shape structure known as SIR stub technique is used to enhance the bandwidth.ii. The inverted L shape structure which is extended from the ground plane is put around the monopole which generates the low resonant frequencies and also broadens the bandwidth. Bandwidth is broadened to 0.8 GHz to 3.5 GHz.iii. For the purpose of more impedance matching, a small patch is etched from the ground plane opposite to the feeding and all the parameters are optimizedResults. that lower 0.9GHz radiation pattern is omnidirectional while at higher frequencies it is quasiomnidirectional, a steady gain greater than 2.8dBi over the entire frequency band i.e from .8 GHz to 3.5 GHz, avery high gain of 6.7 dBi at 0.9 GHz. The compact wide band planar MIMO antenna has over 80% efficiency over most of the working recurrence For handy application ECC value less than 0.5 is adequate for mobile phones. The measured ECC is less than 0.36 over complete operating frequency band, which is all right for mobile phonesConclusions. The paper presents compact planner two port MIMO antenna with wideband width and high gain. The proposed antenna achieved a wide bandwidth from 0.8GHz to 3.5GHz covering 2G/3G/4G bands and Wi-Fi (2.45GHz). High isolation between antenna elements, lower ECC and high diversity gain makes the design of the compact planner wide band MIMO antenna a suitable possibility for mobile phone applications.

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

This paper introduces a new compact Chair-shaped MIMO antenna with two radiating elements and a single layer of frequency-selective surface (FSS) for 5G Sub-6GHz communication systems. They use two techniques, Parasitic element, and (FSS), for isolation and gain enhancement, respectively. The 1 × 2 MIMO antenna using a coplanar waveguide (CPW) fed. Moreover, an FSS array structure consisting of (a 68-unit) Square-shaped structure with Circular Slot (SCS) shaped cells is employed using a new technique (Surround Technique) to enhance the gain and isolation between the elements of the MIMO antenna. The proposed MIMO antenna system is printed on a Rogers 4350B substrate with a thickness of 0.508 mm. The antenna’s performance is evaluated using S-parameters, radiation properties, and MIMO characteristics. The MIMO antenna system works in the Sub 6-GHz 5G band, which ranges from 3 to 6 GHz. Adding the FSS layer enhances the MIMO’s antenna gain to a peak measured gain of 7.96 dBi and it also improves the MIMO antenna’s isolation. The performance metrics of the proposed MIMO antenna were also investigated, including measures values of ECC = 0.004, DG = 9.99 dB, CCL = 0.2 bit/s/Hz, MEG = -3.13 dBi, and TARC = > 0dB) exhibits advantageous antenna characteristics. The observed radiation characteristics of the suggested MIMO antenna system indicate its suitability for the upcoming 5G communication systems.

This work presents a compact 2-port MIMO antenna based on quarter-mode substrate integrated waveguide (QMSIW) technology, operating at 3.5 GHz for WiMAX applications with a 200 MHz bandwidth (3.4–3.6 GHz). QMSIW reduces the antenna size by approximately 75% compared to full-mode SIW. A parasitic patch embedded within the cavity, excited by the quarter-TE110 mode, extends the bandwidth by ∼50% through hybrid resonances at 3.4 and 3.5 GHz. Two rectangular slots are incorporated into the patch to increase its effective electrical length without enlarging the structure. The antenna is fabricated and experimentally validated. In the MIMO configuration, two elements are orthogonally placed, achieving intrinsic port isolation of around 40 dB. Performance metrics include an ECC of 0.02, diversity gain of 9.95 dB, a CCL of less than 0.15 bits/s/Hz, and a TARC less than −14 dB across various angles. The proposed antenna offers a low-profile, compact, and efficient design, ideal for integration in modern handheld wireless devices.

This paper presents a compact dual-band MIMO antenna that is compatible to the IEEE 802.11n wireless LAN standards. The MIMO antenna contains two tree-type elements placed back to back with distance of one-sixth wavelength of 2.4GHz; the element in the MIMO antenna is structured with a two-branch tree-type planar inverted-L monopoles, the lengths in both branches are set to the electrical quarter-wavelength of the frequency bands of 5.2GHz and 2.4GHz respectively. The MIMO antenna characterized by small size, low mutual coupling effect and nearly omni-directional coverage in radiation pattern make it entirely applicable to the mobile wireless network applications. The measurement results of the fabricated MIMO antenna demonstrate the success of the suggested design topologies.

A compact 6-port MIMO antenna consisting of equilateral triangle elements have demonstrated in order to miniaturize the size and reduce the mutual coupling of antenna elements due to its geometrical shape. The antenna is designed on FR4 material and simulated results by HFSS software are provided. The simulated results show that the proposed MIMO antenna achieves the return loss of less than -10 dB and the mutual coupling of less than -12.5 dB between elements in a bandwidth ranging from 2329 to 2495 MHz, which entirely covers WLAN frequency band allocated from 2400 MHz to 2480 MHz. The obtained results indicate that the proposed antenna is a good candidate for MIMO applications.

This article proposes a compact (43 × 26 × 0.8 mm3) dual-band two-element metamaterial-inspired MIMO antenna system with high port isolation for LTE and WiMAX applications. In this structure, each antenna element consists of a square–ring slot radiator encircling a complementary split ring resonator. A tapered impedance transformer line feeds these radiating apertures and shows good impedance matching. A 2 × 3 array of two-turn Complementary Spiral Resonator structure between the two antenna elements provides high dual-band isolation between them. The fabricated prototype system shows two bands 2.34 – 2.47 GHz (suitable for LTE 2300) and 3.35 – 3.64 GHz (suitable for WiMAX). For spacing between two antennas of 10 mm only, the measured isolation between the two antenna elements in the lower band is around −32 dB while that in the upper band is nearly 18 dB. The system shows a doughnut-shaped radiation patterns. The peak measured antenna gains for the proposed MIMO system in the lower and higher bands are 3.9 and 4.2 dBi, respectively. The MIMO system figure of merits such as the envelope correlation coefficient, total efficiency are also calculated and shown to provide good diversity performance.

This paper presents compact Π-shaped dual band microstrip antenna for wireless applications. The proposed microstrip patch Π-shaped 2×2 MIMO antenna has compact size of 30×26mm. This Π shaped antenna radiator has Dual bands which ranges from band I 2.38–2.8GHz, Band II 3.0–3.80 GHz. It covers wireless devices including WLAN, LTE and WiMax. The presented Π-shaped antenna has been analyzed, designed, stimulated and investigated using CST simulator. The proposed design antenna is fabricated with FR-4 substrate. It can measure the parameters of scattering matrices, radiation pattern, gain, directivity, VSWR, return loss.

A dual band MIMO antenna has been proposed for WLAN applications. The antenna comprises of two cup-shaped mounted with T-shaped structure monopole antennas placed parallel to each other with separated ground planes. The antenna is printed on an FR4 substrate of size 40 mm × 40 mm, both the antennas are fed with 50 Ω microstrip lines. The antenna operates at two WLAN bands including the IEEE 802.11 2.4 GHz (2.4–2.484 GHz) and 5.2 GHz (5.15–5.35 GHz). The isolation between the two antennas is provided by a microstrip line in ground plane separating the two antenna elements. The proposed antenna with compact size, simple design and good diversity performance as the value of envelope correlation coefficient remains below 0.003 in both the bands of operation is good for MIMO applications. The proposed scheme can drastically improve the performance of MIMO communications because of exploiting the diversity.

This paper presents a compact MIMO antenna with high isolation enabled by defected ground structure (DGS). The MIMO antenna operates around 5.35 GHz in WLAN frequency band. The overall size of the MIMO antenna is 16 mm×22 mm, i.e., 0.28 λ 0 × 0.39 λ 0 at 5.35 GHz. Isolation greater than 18 dB between the antenna elements and envelope correlation coefficient (ECC) less than 0.02 are obtained in the 5.21-5.5 GHz operating frequency band, whereas the edge-to-edge separation between the elements is 0.069λ0. The peak realized gain is 2.25 dBi at 5.35 GHz.

A compact multiband MIMO antenna using a symmetric slotted structure is proposed for next generation USB dongle applications. The proposed MIMO antenna consists of two triple-band PIFAs with a symmetric slotted structure. The first resonance frequency is controlled by the total length of the main radiating strip with coupling slits (slit 1 and slit 2), which has a length of 70 mm (about 0.18 wavelengths at 0.77 GHz). The second one can be obtained by inserting on additional slit (slit 3) for WCDMA band. Moreover, the third resonance frequency can be tuned by the width of coupling slits (slit 1 and slit 2) and the position of the port 1 and 2 (P <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> and P <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ) to cover M-WiMAX Band (2.5–2.69 GHz). To obtain a high isolation characteristic between two antennas, a symmetric slotted structure and the jointed shorting line are used to reduce the interaction between the two PIFAs. The proposed MIMO antenna has an isolation of approximately 15 dB and the envelope correlation coefficient (ECC) of the two antennas is less than 0.2 over the whole wanted frequency bands.

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.

Design of a compact quad-radiating element MIMO antenna for LTE/Wi-Fi application

A frequency-reconfigurable antenna for a multiple-input-multiple-output (MIMO) system with electronically steerable radiation patterns in azimuth plane is proposed in this letter. For MIMO systems, the steerable radiation patterns are able to reduce the correlation between signals and increase the channel capacity. There are two folded-monopole electronically steerable parasitic array radiator (FM-ESPAR) antennas in the proposed MIMO antenna system in this letter. The radiation pattern of each FM-ESPAR antenna is steerable in azimuth plane from 0 to 360 . Its frequency is reconfigurable between 2.3 and 2.6 GHz. A top-disk loaded monopole and folded monopoles are employed to reduce the height of each FM-ESPAR antenna to 12 mm (λ/10 at 2.4 GHz). The FM-ESPAR antennas are separated from each other by using a 30-mm-long sleeve ground plane. The measured results confirm that the MIMO antenna comprising two FM-ESPAR antennas achieves good isolation at any angle between the main lobes of the FM-ESPAR antennas. The proposed MIMO antenna has compact size, electronically steerable beams, and frequency-agile capability.

In this paper, a compact MIMO antenna with improved isolation is proposed for WLAN applications. The overall dimension of the antenna is only 35 mm × 62 mm. Two identical monopole patch antennas are backed by a modified ground plane. Three rectangular cuts on each antenna element along with modified ground plane are responsible for higher isolation of about 40 dB at 5.5 GHz. The antenna prototype is printed on FR4 substrate (e r =4.4, tanδ=0.02) of thickness 1.5 mm. The measured result show that the −10dB impedance bandwidth of 5.25 − 5.75 GHz for WLAN. The reflection coefficient, mutual coupling, current distribution, radiation patterns, and gain have been simulated to justify the functionality of the MIMO antenna.