Ultra-wideband MIMO Antenna Research Articles

Dual-circular slotted low-profile ultrawideband textile MIMO antenna with ground slot stub for Sub-6G, ISM, and IoT applications

Dual-circular slotted low-profile ultrawideband textile MIMO antenna with ground slot stub for Sub-6G, ISM, and IoT applications

Highly isolated electrically compact UWB MIMO antenna for wireless communications applications

A multiple-input multiple-output Ultra-Wide Band (UWB) antenna with a compact size of 0.8λ x 0.7λ is proposed. The presented structure is constituted with patch geometry on a planar surface. The radiator consists of three counter U-shaped conducting strips united with a patch structure where two are positioned nearby and the third geometry covers the remaining conducting strips. A corrugated design has been created on a ground plane in which zigzag pattern slots are engineered to receive high isolation of more than 20 dB. The configured antenna radiates over a wide frequency spectrum of 3.10 GHz–11.85 GHz. It offers a fractional bandwidth of 195 % with a gain of 2.80 dBi, 3.08 dBi, and 2.72 dBi for targeted resonances. The antenna radiation patterns and MIMO diversity parameters are also presented. The acceptable values of ECC (<0.05 abs), MEG (−6 dB to −8 dB), CCL (<0.02 bits/sec/Hz) were found. The fabricated model was tested inside an anechoic chamber environment to receive the measured response with optimum accuracy through multiple iterations. The measured response shows a strong correlation with numerically computed responses finding the presented antenna suitable for WiMAX, WLAN (max protocol) and radar applications.

A Four Port Flexible UWB MIMO Antenna with Enhanced Isolation for Wearable Applications

This article presents a four-port multiple-input-multiple-output (MIMO) flexible antenna design for Ultrawideband (UWB) application using Polydimethylsiloxanes substrate. The single UWB antenna structure consists of modified circular radiator with elliptical slot and partial ground plane. To achieve high isolation among antenna element, a Defective Ground Structure (DGS) is adopted to decouple the low frequency band. DGS comprises a centrally placed square shape slotted structure connected by horizontal and vertical lines, achieving isolation below -20 dB. The proposed antenna has a dimension of , bandwidth of 3.4–11.8 GHz (110.5%) and 4.3 dBi peak gain. Simulation and measurement findings show that the antenna performs well under bending situations with different curvature radius. At 4 GHz and 8.1 GHz, W/kg specific absorption rate (SAR) for 1/10 g tissue is examined. A low value of SAR is obtained at both the resonating frequencies. Additionally, an analysis is conducted on the diversity parameters, and the antenna demonstrates comparatively good results having mean effective gain (MEG) ratio < -3 dB envelope correlation coefficient (ECC) < 0.02, total active reflection coefficient (TARC) < − 10 dB, channel capacity loss (CCL) < 0.3 bps/Hz, and diversity gain (DG) > 9.99 dB, implying that it's appropriate for wearable MIMO applications.

A high-isolated wideband two-port MIMO antenna for 5G millimeter-wave applications

Fifth-generation (5G) technology is extremely important in the current context since it seeks to fix the shortcomings of its predecessors, the 4G generation. To achieve this goal, this project entails constructing a small ultra-wideband (UWB) MIMO antenna featuring an anti-parallel layout, designed for operation within the millimeter-wave spectrum. Moreover, the investigation scrutinizes and fine-tunes the mutual coupling interaction between the two elements in detail. The presented MIMO antenna occupies a small footprint of 6 × 17.37 mm2. Despite its compact dimensions, this MIMO antenna provides an impressive isolation of 65 dB, attributed to the adequate inter-element spacing and the anti-parallel arrangement. Additionally, the integration of a defected ground structure (DGS) enhances isolation by approximately 20 dB. Furthermore, the proposed MIMO antenna demonstrates a satisfactory gain of approximately 6 dBi, boasting high efficiency surpassing 96 %, and lying between 34.1 and 39.7 GHz. The proposed antenna has undergone simulation and analysis utilizing both the High-Frequency Structure Simulator (HFSS) and Computer Simulation Technology (CST) in order to confirm its utility. Based on these findings, the suggested MIMO antenna appears to be well-suited for compatibility with 5G communication systems, specifically covering the n260 band (37–40 GHz) and the Ka-band.

A compact UWB MIMO antenna augmented with isolation improvement structures in situ with ground stubs and slots

Abstract An orthogonally oriented microstrip-fed bi-element ultra-wideband (UWB) diversity antenna possessing a super-wide bandwidth, high isolation, and band rejection attributes is proposed. The intended diversity antenna uses a 2nd-order Cayley fractal tree-shaped neutralization line among a pair of radiating square monopoles along with additional components like extended ground stubs, hybrid Koch fractal parasitic elements, and an L-shaped defected ground structure to attain high isolation of &lt;−20 dB over 3.1–18 GHz. To nullify the intervention from the existent wireless local area network band, a hybrid Koch–Minkowski slot is carved out from the radiators. A minimal inter-element spacing of 8 mm is attained with the suggested layout measuring 28 mm (L) × 42 mm (W) in extent. The numerical as well as experimental investigations of vital diversity attributes like the envelope correlation coefficient, mean effective gain, total active reflection coefficient, and multiplexing efficiency depict high diversity actualization. The consistency amidst the simulation as well as the empirical results recommends the worthiness of the intended antenna for handy UWB and UWB multiple-input multiple-output systems.

Compact triple band notched UWB MIMO antenna with integrated GSM

SummaryThis paper introduces an innovative four‐element Ultra‐wideband (UWB) MIMO structure featuring an integrated global system for mobile (GSM) antenna with the ability to achieve dual and triple band‐notch capabilities. The antenna's distinctiveness is achieved through the utilization of four directional meandered line shaping decoupling structures (MLSDS), an orthogonal arrangement, and multi‐slot techniques. The incorporation of orthogonal separation alongside four directional MLSDS significantly reduces the mutual interference between radiating elements. By placing MLSDS on both sides of the substrate, effective coverage of the GSM band is achieved. The development of the MIMO structure unfolds through four distinct phases. The initial stage lacks MLSDS, while the second stage incorporates MLSDS. The third and fourth stages respectively introduce MLSDS with dual and triple notch characteristics. The presence of MLSDS enhances the antenna's impedance bandwidth (IBW). The intended notches are tailored to address interference from bands like Band n41, WLAN, and X‐band. Furthermore, the proposed antenna has undergone simulation, measurement, and comparative analysis with existing models, focusing on diversity performance metrics. The results reveal its exceptional diversity performance, positioning it as a potential choice for creating a portable UWB‐MIMO system.

Three‐element ultrawideband MIMO antenna based on shared‐radiator structures with high efficiency and gain

AbstractThis letter presents a novel three‐port ultrawideband (UWB) multi‐input‐multi‐output (MIMO) antenna that covers the sub‐6 GHz (between 1.7 and 6 GHz) frequency band for wireless device applications. The proposed antenna consists of two parts: a dipole and two centrosymmetric slot antennas with shared structures. The radiating arm of the dipole can be reused as the large slot ground without increasing the size. The novel circular slot antenna etched on the radiator and circular microstrip feed line are designed to achieve wide impedance bandwidth. Meanwhile, four chamfers are loaded at the corners of the dipole to further optimize the impedance match in the whole frequency band. The physical dimension of the proposed three‐port MIMO antenna is 70 × 45 × 0.762 mm3. Experimental results validate that the reflection coefficient remains lower than −12 dB and the port isolation is better than 12 dB in the entire operational bandwidth without any decoupling network. The measured average peak gains are up to 5.6 dBi for all three ports, accompanied by a radiation efficiency of 90% across the frequency spectrum. With the advantages of simple design, high gain and high radiation efficiency, the proposed three‐element MIMO antenna design is well‐suited for implementation in UWB applications.

Circular split ring resonator (SRR) slot and ground stub based slotted circular ultra-wideband MIMO antenna with WLAN band exclusion and high isolation performance

Circular split ring resonator (SRR) slot and ground stub based slotted circular ultra-wideband MIMO antenna with WLAN band exclusion and high isolation performance

Design of a Compact Dual Port 2 × 1 Ultra-Wideband MIMO Antenna for Radio Frequency Energy Harvesting Based on Four ``A" Shaped Slots

Design of a Compact Dual Port 2 × 1 Ultra-Wideband MIMO Antenna for Radio Frequency Energy Harvesting Based on Four ``A" Shaped Slots

Two Elements Orthogonally Placed UWB-MIMO for RADAR, Satellite and Terrestrial Communications

In this paper, a novel approach to design a compact ultrawideband (UWB) Multi-Input-Multi-Output (MIMO) antenna is presented. The proposed design consists of two elliptical monopoles placed orthogonal to each other for mutual coupling reduction. The design is integrated with three parallel coupled line strips for further mutual coupling reduction between the antenna elements. The physical dimension of the proposed design is 35 x 35 x 1.6 mm designed in low cost FR-4 substrate resulting in UWB characteristics in the WLAN range. The proposed design demonstrates good performance in the frequency range of 4.66 GHz to 12.42 GHz having large bandwidth of 7.76 GHz, with a mutual coupling of better than-20 dB in the entire band. The diversity performance, as measured by the correlation coefficient (ECC) and diversity gain (DG), is excellent, and within the acceptable range which proves that the proposed compact UWB MIMO antenna is a suitable candidate for RADAR, Satellite and Terrestrial Communications.

Ultra-wideband MIMO antenna with reconfigurable band notch characteristics and improved isolation

This paper introduces an ultra-wideband (UWB) dual-element MIMO antenna with reconfigurable band-notched characteristics. The antenna comprises a partial elliptical radiator patch with a partial trapezoidal notched ground and has a fractional bandwidth of 120%. By incorporating two inverted U-shaped slots and three PIN diodes, the antenna can switch between dual, single, and no notches, enabling reconfigurable band notches for WIMAX (3.5 GHz), sub6 5G band (4.5 GHz), and satellite communication band (7.5 GHz). The proposed structure has been extended to a two-element MIMO in a side-by-side arrangement, achieving isolation characteristics below -30 dB over the bandwidth by incorporating stubs between the antenna elements. The MIMO antenna has acceptable diversity performances, and the switching characteristics remain unperturbed. The time-domain behavior shows that the structure can handle impulse signals. The overall substrate dimension of the dual-element MIMO is 1.4λ0×0.7λ0. The simulated and measured results are in good agreement.

Design and analysis of metasurface-based CPW-Fed UWB MIMO antenna for wireless communication systems

A compact 4-port coplanar waveguide (CPW) fed ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna with enhanced isolation is proposed to operate from 3.66 GHz to 16.61 GHz with 127.78% impedance bandwidth. The proposed antenna system consists of 4 orthogonal arrays of monopole antennas improved by four iterations. The UWB characteristic of the antenna is obtained from an improved monopole antenna fed by CPW. The final MIMO antenna is machined on a Rogers 4003C substrate with dimensions of mm3. The orthogonal arrangement of antennas brings about the polarization diversity and certain isolation of MIMO antennas. Four rows of orthogonal metasurface elements with via holes and the ring of the backplane further improve the isolation between antenna elements in the MIMO system. The MIMO antenna has an impedance bandwidth of 12.95 GHz with dB and good isolation ( dB and dB). In particular, S31 is always less than −25 dB at frequencies greater than 6 GHz. The measured results of MIMO antenna agree with the simulated results. The optimized MIMO antenna has excellent performance in many aspects, such as UWB, compact size, omnidirectional radiation, enhanced isolation and high efficiency, which means that it has application potential in UWB wireless communication systems.

Integrated Narrow Band (NB) and UWB MIMO Antenna for IoT Applications

In this work, we integrated narrow band (NB) and Ultra-Wide Band (UWB) four-port MIMO antennas designed and implemented in IoT applications. The designed antenna consists of two quarter-wavelength asymmetrical NB radiators and a reverse P-shaped UWB radiator. The two NBs are generated by two quarter-wavelength non-identical radiators, and the UWB is generated by a semi-circle-shaped monopole radiator. Further, the NB radiators and UWB radiators are connected in a 3-mm-wide feed line. The antenna is designed to operate at 1.8 GHz (3G), 2.4 GHz (WLAN), and 3.1–12 GHz (UWB) for IoT applications. In this designed four-port MIMO antenna, two proposed NB and UWB radiators are mounted on the front side of the FR4 substrate and the other two on the rear side of the FR4 substrate. The proposed MIMO antenna has a dimension of 65 × 65 × 1.6 mm 3 . The antenna performance and MIMO performance are analyzed. The diversity metrics such as ECC, DG, TARC, MEG, and CCL are computed, and their values are 0.26, 9.87 dB, −22 dB, −6 dB, and 0.27 bits/Hz/s, respectively, within the bounds. The real-time implementation of the designed antenna is demonstrated at 2.4 GHz for smart home applications.

Wideband, High-Gain, and Compact Four-Port MIMO Antenna for Future 5G Devices Operating over Ka-Band Spectrum

In this article, the compact, ultra-wideband and high-gain MIMO antenna is presented for future 5G devices operating over 28 GHz and 38 GHz. The presented antenna is designed over substrate material Roger RT/Duroid 6002 with a thickness of 1.52 mm. The suggested design has dimensions of 15 mm × 10 mm and consists of stubs with loaded rectangular patch. The various stubs are loaded to antenna to improve impedance bandwidth and obtain ultra-wideband. The resultant antenna operates over a broadband of 26.5–43.7 GHz, with a peak value of gain &gt;8 dBi. A four-port MIMO configuration is achieved to present the proposed antenna for future high data rate devices. The MIMO antenna offers isolation &lt;−30 dB with ECC of &lt;0.0001. The antenna offers good results in terms of gain, radiation efficiency, envelop correlation coefficient (ECC), mean effective gain (MEG), diversity gain (DG), channel capacity loss (CCL), and isolation. The antenna hardware prototype is fabricated to validate the performance of the suggested design of the antenna achieved from software tools, and good correlation between measured and simulated results is observed. Moreover, the proposed work performance is also differentiated with literature work, which verifies that the suggested work is a potential applicant for future 5G compact devices operating over wideband and high gain.

New Design of a Compact 1×2 Super UWB-MIMO Antenna for Polarization Diversity

This paper proposes a new design of compact coplanar waveguide (CPW) fed -super ultra-wideband (S-UWB) MIMO antenna with a bandwidth of 3.6 to 40 GHz. The proposed antenna is composed of two orthogonal sector-shape monopoles (SSM) antenna elements to perform polarization diversity. In addition, a matched L-shaped common ground element is attached for more efficient coupling. The FR-4 substrate of the structure with a size of 23 × 45 × 1.6 mm3 and a dielectric constant of 4.3 is considered. The proposed design is simulated by using CST Microwave Studio commercial software. The simulation shows that the antenna has low mutual coupling (|S21| &lt; -20 dB) with |S11|&lt;−10 dB, ranging from 3.6 to 40 GHz. Envelope correlation coefficient (ECC) is less than 0.008, diversity gain (DG) is more than 9.99, mean effective gain (MEG) is below – 3 dB, and total active reflection coefficient (TARC) is less than -6 dB over the whole response band is reported. The proposed MIMO antenna is expected efficiently cover the broadest range of frequencies for contemporary communications applications.

SAR reduction using dual band EBG method based on MIMO wearable antenna for WBAN applications

A wearable ultra-wideband MIMO antenna using conductor and polyester fiber fabrics is proposed in this paper. The antenna’s total dimension is 115 × 70 mm2. As a result, the antenna can be installed on curved or bent surfaces due to its flexibility. This proposed antenna has a frequency range of 2 GHz – 30 GHz, a gain of 3.75 dBi on average, and a correlation coefficient of 0.5. That can be utilized for interior installation of the 5G frequency spectrum (2.6 GHz and 26 GHz), as well as WBAN application (2.4 GHz, 5.2 GHz, and 3.1 GHz – 10.6 GHz). Additionally, the researchers designed an electromagnetic band gap (EBG) and constructed a square loop plate with a square plate that reflects resonance characteristics in the 2.4 GHz and 5.2 GHz bands by placing unit cells in 3 × 5 cells to decrease the antenna’s specific absorption rate (SAR). The proposed antenna with EBG could minimize the SAR values to 0.088 W/kg and 0.070 W/kg, which obtains a gain of 6.59 dBi and 11.6 dBi, at 2.4 GHz and 5.2 GHz, respectively. Also, the results are lower than the conventional SAR value of 2.0 W/kg at 10 g.

A Miniaturized Ultra-wideband MIMO Antenna Design with Dual-band Notched Characteristics

A Miniaturized Ultra-wideband MIMO Antenna Design with Dual-band Notched Characteristics

A compact triple band-notched quasi-self-complementary UWB MIMO antenna decoupled by SRRs

AbstractIn this paper, a compact four-element quasi-self-complementary (QSC) ultra-wideband (UWB) multiple-input multiple-output antenna with triple band-notched characteristics is proposed. Coplanar waveguides fed QSC structure is designed as radiation element to achieve wideband and small size. Besides, regular hexagonal split-ring resonators with single negative properties are designed and added on the back of the substrate to obtain high isolation in the whole operating band. Moreover, a double-fork-shaped slit is etched in each radiating element to generate three notched bands covering 3.63–4.24, 5.15–5.98, and 7.17–8 GHz. The experiment results indicate that the isolation of the proposed antenna is higher than 22 dB and the peak gain varies from 2.5 to 6.7 dB in the entire band of 3–18 GHz, which demonstrates that it is suitable for UWB applications.

Design of a Novel Circularly Polarized MIMO Antenna with Enhanced Isolation for Ultra-wideband Communication

In this paper, we propose a circularly polarized (CP) ultra-wideband (UWB) MIMO antenna. Compared with common linearly polarized (LP) UWB antenna, the proposed antenna can excite circular polarization (CP) mode for WLAN communication and its impedance bandwidth can also fully cover UWB spectrum. It consists of identical circularly polarized antennas. Each unit adopts circular monopole with extended orthogonal rectangle patch to realize broadband and symmetrical rectangular ground with slot in the diagonal of each antenna unit to achieve circular polarization for WLAN band. It has a very compact size and the dimension is 25 × 51 × 0.8 mm3. The impedance bandwidth of the proposed antenna is from 3.1 GHz to 13.5 GHz, with average gain of 4 dBi, fully covering UWB bandwidth and enhanced by 38%. At the same time, circular polarization is achieved by embedding two symmetrical rectangular slot structures in the two opposite corners of every antenna unit. The extended orthogonal rectangle patch is introduced to enhance impedance bandwidth and broaden axial ratio (AR) bandwidth. The measured 3 dB axial ratio (AR) bandwidth is 1.8 GHz (4.7-6.5 GHz), fully covering WLAN band. Meanwhile, the slit slot between antenna units and rectangular openings are introduced to achieve high isolation. The proposed antenna keeps ECC (envelope correlation coefficient) below 0.01, which showing good isolation and diversity characteristics. The proposed antenna can simultaneously operate in the UWB spectrum and exhibit circularly polarized (CP) radiation characteristic in WLAN.

Design and investigation of unique shaped low-Profile material-based superlative two-element printed ultrawideband MIMO antenna for Zigbee/WiFi/5G/WiMAX applications

The presented manuscript represents the superlative 1 × 2 MIMO antenna structure. Eight designs were analyzed by the patch elements' varying shapes and inserting the slits in the ground regions. The overall dimensions of the structure are 50 × 39 × 1.6 (mm3). The low-profile substrate FR4 is used for the fabrication, and the reflectance response of simulated and measured designs are compared. The insertion L shaped slits in the ground region and engraving of the patch elements provide the wider isolation bands. The minimum S11 is −67.53 dB, a broader bandwidth of 5.653 GHz, and a peak gain of 8.72 dBi. The design concert also analyzed ECC, CCL, TARC and DG. These results reflect the presented design's behaviour as per the standard requirements. The response of the design is also compared with the previously published works to identify the improvement. The work targets wireless applications like WLAN, weather broadcast, Satellite and Military.