Multiple-input And Multiple-output Antenna Research Articles

Compact Quad Band MIMO Antenna Design with Enhanced Gain for Wireless Communications.

In this paper, a novel microstrip line-fed meander-line-based four-elements quad band Multiple Input and Multiple Output (MIMO) antenna is proposed with a gain enhancement technique. The proposed structure resonates at four bands simultaneously, that is, 1.23, 2.45, 3.5 and 4.9 GHz, which resemble GPS L2, Wi-Fi, Wi-MAX and WLAN wireless application bands, respectively. The unit element is extended to four elements MIMO antenna structure exhibiting isolation of more than 22 dB between the adjacent elements without disturbing the resonant frequencies. In order to enhance the gain, two orthogonal microstrip lines are incorporated between the antenna elements which result in significant gain improvement over all the four resonances. Furthermore, the diversity performance of the MIMO structure is analyzed. The Envelope Co-Relation Coefficient (ECC), Diversity Gain (DG), Channel Capacity Loss (CCL), Mean Effective Gain (MEG) and Multiplexing Efficiency are obtained as 0.003, 10 dB, 0.0025 bps/Hz, −3 dB (almost) and 0.64 (min.), respectively, which are competent and compatible with practical wireless applications. The Total Active Reflection Coefficient (TARC) resembles the characteristic of the individual antenna elements. The layout area of the overall MIMO antenna is 0.33 λ × 0.29 λ, where λ is the free-space wavelength corresponding to the lowest resonance. The advantage of the proposed structure has been assessed by comparing it with previously reported MIMO structures based on number of antenna elements, isolation, gain, CCL and compactness. A prototype of the proposed MIMO structure is fabricated, and the measured results are found to be aligned with the simulated results.

An ultra-wideband MIMO antenna for 5G smartphone

In this letter, a multiple-input and multiple-output (MIMO) antenna with ultra-wideband performance for 5G smartphones is investigated. Firstly, a compact antenna-element with a size of 8×7mm2 is proposed. The antenna-element is designed as a shorted rectangular patch with a reclined-F slot etched on it. The antenna-element operates with a wide bandwidth of 88% which is contributed by the multiple-mode resonance and L-shaped coupling excitation. Then, eight identical antenna-elements are arranged on the bezels to constitute an 8×8 MIMO antenna. At last, to demonstrate our design mechanism, a prototype of the proposed MIMO antenna is fabricated and measured, achieving a good agreement between the measurement and simulation. The proposed MIMO antenna covers the entire 5G NR bands and part of the LTE bands with decent in-band isolations higher than 10 dB and total efficiencies varied from 40% to 75%.

Design of compact multiple‐input and multiple‐output antenna based on slow‐wave corrugated strips

A method of designing two-element compact multiple-input and multiple-output (MIMO) antennas with good isolation based on slow-wave corrugated strips (CSs) is presented in this paper. Using the slow-wave characteristic, a pair of CSs is applied as arms of each dipole antenna element to realise the compact design. A metal plane is placed between the two dielectric boards serving as the reflector so that the antenna can achieve good forward radiation. There are two coupling paths between the closely placed antennas: the coupling between the adjacent antenna arms and the coupling with the reflector. By adjusting the phase constants of the two coupling paths, good isolation is achieved in the operating frequency band without any additional de-coupling structures. A sample of a two-element MIMO antenna is fabricated at the centre frequency of 5.1 GHz with a bandwidth of 330 MHz. Measured results show good performance to support the design method. As each arm is about 1/8λ0 (λ0 is wavelength in free space), the edge-to-edge distance is 0.04λ0, and the isolation in the operating frequency is 15 dB.

An ultra‐thin flexible four port MIMO antenna for WBAN communications

AbstractThis letter reports the design of a quasi Yagi‐Uda Antenna developed on an ultra‐thin flexible material for wireless body area networks (WBAN). The proposed planar Yagi‐Uda antenna operates at 2.45 GHz ISM band for medical applications. The microstrip line to slot line transition with circular geometry is used to obtain the necessary impedance matching. The proposed antenna has a footprint of 42 × 36 mm with a profile height of 0.05 mm. The quasi Yagi‐Uda antenna with a set of two directors exhibits 5% bandwidth with a unidirectional radiation pattern and a peak gain of 4 dBi. A four‐port multiple input and multiple output (MIMO) antenna is later developed to meet the diversity requirements of body‐centric communications. To improve the front‐to‐back ratio and specific absorption rate, the MIMO antenna is backed by a metallic reflector. The on‐body performance of the antenna are studied and the results are presented. The estimated envelope correlation coefficient is less than 0.4, apparent diversity gain is greater than 8 dB and effective diversity gain is above 7.2 dB for the proposed four‐element MIMO antenna. The prototype antenna is fabricated and the results indicate that the proposed antenna is suitable for WBAN communications.

Wireless body-area network monitoring with ZigBee, 5G and 5G with MIMO for outdoor environments

Wireless body area network (WBAN) works near or inside the human body and is characterized by its accuracy in sending and receiving data. It works for long hours and must be low in energy consumption. One of its problems is that the transmission and reception distance is few and does not exceed a few meters. We worked on simulations based on a network consisting of ZigBee or fifth-generation (5G) and 5G with multiple-input and multiple-output (MIMO) nodes to deliver information to the center (hospital) at a 2.4 to 2.8 or 5 GHz frequency to solve this problem. Suppose the sensors are connected to the Arduino, which in turn is connected to the transmitter connection. The proposed method transmits data obtained from the sensor that touched the patient by multi-node to the hospital. The suggested method shows the best scenario to reduce energy consumption based on the number of active nodes. Based on the results obtained, we have noticed that ZigBee devices reduce energy use, perform better, and significantly extend the life of the nodes. While 5G devices increased the response speed in transferring data. In addition, MIMO antennas have the advantage of adding more stability in the connection between nodes.

Design of an isolation improved MIMO antenna using metasurface based absorber for wireless applications

The paper intends to present a design of isolation improved MIMO (multiple-input and multiple output) antenna with two elements achieving operating band from 4.04 GHz to 5.48 GHz for wireless applications. The MIMO configuration is comprised of two antenna elements that are maintained at two extreme edges of substrate having dimension of 100 × 50 × 0.8 mm3. The incorporation of metasurface based isolator between MIMO antenna elements provide exceptional isolation (< −23 dB) for practical mobile and wireless application. The mutual coupling of unwanted field between MIMO antenna elements acts as major deterrent to exploit the optimum performance for MIMO antenna. The work focus on design and development of MIMO elements with metasurface based isolator (acting as absorber) clearly with an intention to provide high order optimum isolation levels between two antenna elements. The surface current distribution mechanism provide insight to the high isolation level achieved through incorporation of metasurface based isolator in MIMO setup. The display of spatial/pattern diversity with the attainment of suitable values of envelope correlation coefficient clearly testify its suitability for MIMO based mobile application in microwave regime.

Frequency re-configurable metal-graphene hybrid MIMO patch antenna for terahertz communication

Abstract This paper proposes a novel metal-graphene plasmonic antenna over a Si/SiO2 substrate, working in terahertz frequency band. Novelty of the work lies in the use of metal and graphene as a patch antenna, as this combination enhances the gain &amp; the radiation efficiency of the whole structure. Besides the analysis provides detailing of graphene and its conductivity modelling using MATLAB. The antenna is analyzed using FDTD based CST software, conductivity of graphene used in CST is verified with the conductivity achieved using MATLAB. Further, a 3-element Multiple Input and Multiple Output (MIMO) antenna system using same single element antenna, is designed &amp; analyzed. The metal-graphene hybrid patch antenna provides maximum directivity around 5.8 dBi, maximum gain around 5 dBi, and high radiation efficiency (approx. 80%) at resonant frequency of 1.8 THz. Besides, the 3-element MIMO antenna provides radiation efficiency around 77%, with directivity around 5 dB &amp; diversity gain of around 10 dBi. The proposed metal-graphene hybrid MIMO patch antenna has the potential to be used in advanced THz communication systems.

Green and Highly Efficient MIMO Transceiver System for 5G Heterogenous Networks

The paper presents the general requirements and an exemplary design of the RF front-end system that in today&#x2019;s handset is a key consumer of power. The design is required to minimize the carbon footprint in mobile handsets devices, whilst facilitating cooperation, and providing the energy-efficient operation of multi-standards for 5G communications. It provides the basis of hardware solutions for RF front-end integration challenges and offers design features covering energy efficiency for power amplifiers (PAs), Internet of Things (IoT) controlled tunable filters and compact highly isolated multiple-input and multiple-output (MIMO) antennas. An optimum design requires synergetic collaboration between academic institutions and industry in order to satisfy the key requirements of sub-6 GHz energy-efficient 5G transceivers, incorporating energy efficiency, good linearity and the potential for low-cost manufacturing. A highly integrated RF transceiver was designed and implemented to transmit and receive a picture using compact MIMO antennas integrated with efficient tunable filters and high linearity PAs. The proposed system has achieved a bit error rate (BER) of less than 10&#x2013;10 at a data rate of 600 Mb/s with a wireless communication distance of more than 1 meter and power dissipation of 18&#x2013;20 mW using hybrid beamforming technology and 64-QAM modulation.

A tri‐band triangular lamp post shaped quad port MIMO antenna

SummaryIn this article, a novel and compact multiband quad port asymmetric coplanar strip‐fed triangular lamp post shaped printed multiple‐input and multiple‐output (MIMO) antenna has been presented. The proposed MIMO antenna is designed and developed on a FR‐4 (εr = 4.4) dielectric (40 × 40 × 1.6) mm3. The proposed MIMO antenna utilizes the pattern diversity technique to obtain the desired isolation among closely spaced radiators. Simulated and measured results indicate that |S11| of proposed lamp post shaped MIMO antenna array &lt; −10 dB, that assures the operation in three frequency bands, namely, (2.27–2.42), (3.38–3.62), and (4.5–6.23) GHz, which are the operating bands of WiBro, Bluetooth, WiMAX, and WLAN/WiMAX, respectively. A peak radiation gain of 5.1 dBi is observed alongside with a maximal radiation efficiency close to 92% in operating band for the proposed MIMO antenna. A minimal isolation of −18 dB between the antenna elements has been observed in all three operating bands, which is necessary for improved performance to achieve high data transfer rates. Performance critical diversity characteristics such as diversity gain (DG), envelope correlation coefficient (ECC), total active reflection coefficient (TARC), mean effective gain (MEG), and channel capacity (CC) of the compact proposed lamp post shaped MIMO antenna have been calculated and found that the correlation coefficient was &lt;0.001 with higher diversity gain &gt; 9.95 dB and achieved better CCL &lt; 0.4 bits/s/Hz in the respective operating bands. With these results, the proposed triangular lamp post shaped MIMO array is suitable for high data rate applications, which is one of the main concerns of 5G and beyond networks.

Hybrid Free Space Optical Communication and Radio Frequency MIMO System for Photonic Interference Separation

We propose and experimentally demonstrate a hybrid free space optical (FSO) communication and radio frequency (RF) multiple-input and multiple-output (MIMO) system for interference separation. The system switches between FSO and RF MIMO modes and makes use of the complementary advantages of the two modes. The MIMO receiver separates signal of interest from in-band interference with blind source separation (BSS), while the separation ratio is limited by the physical dimensions of the MIMO antenna array. With FSO channel, the system achieves over 30dB signal to interference plus noise ratio, so the wireless system can transmit signals with high orders of modulation. When the FSO channel is blocked and line-of-sight transmission condition is not satisfied, the system switches to the RF MIMO mode for interference cancellation. The wireless system maintains continuous transmission at a lower bit rate. Both the FSO mode and the RF MIMO mode can be seamless integrated with photonic signal processing system for wideband and real-time interference cancellation.

Design of multiple-input and multiple-output antenna for modern wireless applications

In this paper, multiple-input and multiple-output (MIMO) antennas are designed and simulated. The designed antennas are compact double-sided printed microstrip patch antennas and fed by a microstrip line. These antennas are designed for 3.5 to 10 GHz frequencies used for medical, industrial, sciences, and various fields of 5G communications and networking applications. Furthermore, a MIMO system is designed using the polarization variability of the individual antennas, which yields better results in terms of mutual coupling (S12 and S21), reflection coefficient (S11 and S22), and voltage standing wave ratio (VSWR), which is less than 2 indicate improved matching conditions. The designed antennas showed an acceptable gain (around 2 dB) and an envelope correlation coefficient (ECC) is &lt;0.002. In addition, the proposed MIMO antennas exhibited isolation is -25 dB at 6 GHz, which is preferable in 5G mobile antennas.

5G/B5G Internet of Things MIMO Antenna Design

The current and future wireless communication systems, WiFi, fourth generation (4G), fifth generation (5G), Beyond5G, and sixth generation (6G), are mixtures of many frequency spectrums. Thus, multi-functional common or shared aperture antenna modules, which operate at multiband frequency spectrums, are very desirable. This paper presents a multiple-input and multiple-output (MIMO) antenna design for the 5G/B5G Internet of Things (IoT). The proposed MIMO antenna is designed to operate at multiple bands, i.e., at 3.5 GHz, 3.6 GHz, and 3.7 GHz microwave Sub-6 GHz and 28 GHz mm-wave bands, by employing a single radiating aperture, which is based on a tapered slot antenna. As a proof of concept, multiple tapered slots are placed on the corner of the proposed prototype. With this configuration, multiple directive beams pointing in different directions have been achieved at both bands, which in turn provide uncorrelated channels in MIMO communication. A 3.5 dBi realized gain at 3.6 GHz and an 8 dBi realized gain at 28 GHz are achieved, showing that the proposed design is a suitable candidate for multiple wireless communication standards at Sub-6 GHz and mm-wave bands. The final MIMO structure is printed using PCB technology with an overall size of 120 × 60 × 10 mm3, which matches the dimensions of a modern mobile phone.

Deep Learning Assisted Automatic Methodology for Implanted MIMO Antenna Designs on Large Ground Plane

This paper provides a novel methodology for designing implanted multiple-input and multiple-output (MIMO) antennas in the automatic fashion. The proposed optimization consists of two sequential phases for firstly configuring the geometry of an implanted MIMO antenna and then sizing the design parameters through the hierarchy top-down optimization (TDO) and regression deep neural network (DNN), respectively. It tackles the difficulty in constructing the structure of antennas and also provides optimal values for the determined variables, sufficiently. This methodology results in valid electromagnetic (EM)-verified post-layout generation that is ready-to-fabricate. The effectiveness of the proposed optimization-oriented method is verified by designing and optimizing the implanted MIMO antenna in the frequency band of 4.34–4.61 GHz and 5.86–6.64 GHz suitable for medical applications at the emerging wireless band. For our design, we employ the actual biological tissues as bone, liquid (%1 sodium chloride, %40 sugar in distilled water), and plexiglass surroundings with a bio-compatible substrate, as aluminium oxide on a large ground plane, that is suitable to be used in a particular biomedical applications involving smart implants.

Compact MIMO antenna using dual-band for fifth-generation mobile communication system

This paper presents the design of a multiple-input and multiple-output (MIMO) antenna for a fifth-generation (5G) smartphone that will work in dual-band. The antenna proposed in this work operates at 2 frequency ranges, i.e., (3300-3600) MHz and (4800-5000) MHz. The antenna design consists of four antennas that are placed perpendicular to the edge of the system and this makes it different from the traditional 5G antennas. The area of each antenna on the side frames is (3.9×17 mm), and hence can be used in ultra-thin smartphones for 5G applications. The reflection coefficient obtained in the simulations is less than -6 dB for the required band, which suggests that the required impedance matching is obtained. The antenna proposed is designed by using central time zone (CST) microwave studio.

Miniaturized MIMO Antenna with Low Inter-radiator Transmittance and Band Rejection Features

In this article, compact a multiple-input and multiple-output (MIMO) system with flag-shaped radiators and a mountain-shaped ground plane is presented. Isolation is enhanced with the help of a decoupling stub placed between radiators, where two bands are stopped with the help of slits etched into the radiators. The overall size of the proposed antenna is 15 mm ×25 mm ×1.6 mm. The reflection coefficients are less than -10 dB between 3–10.9 GHz, except the bands WiMAX (3.2–3.7 GHz) and WLAN (5–6 GHz); similarly, measured and simulated transmission coefficients are less than -20 dB across the entire band of UWB. The envelope correlation coefficient (ECC) is less than 0.02 and the diversity gain is greater than 9.9 dB. The gain, ECC, radiation pattern, multiplexing efficiency, diversity gain and various other parameters are discussed and evaluated in detail.

Broadband Dual-Polarized 2 × 2 MIMO Antenna for a 5G Wireless Communication System

In this study, we proposed an indoor broadband dual-polarized 2 × 2 MIMO (multiple-input and multiple-output) antenna having dimensions of 240 mm × 200 mm × 40 mm, for application in 5G wireless communication systems. The proposed antenna comprised two vertically polarized circular monopole antennas (CMAs), two horizontally polarized modified rectangular dipole antennas (MRDAs), and a ground plane. The distance between the two MRDAs (MRDA1 and MRDA2) was 70.5 mm and 109.5 mm in the horizontal (x-direction) and 109.5 mm vertical (y-direction) directions, respectively. Conversely, the distance between the two CMAs (CMA1 and CMA2) was 109.5 mm and 70.5 mm in the horizontal (x-direction) and vertical (y-direction) directions, respectively. While the CMAs achieved broadband characteristics owing to the optimal gap between the dielectric and the driven radiator using a parasitic element, the MRDAs achieved broadband owing to the optimal distance between the dipole antennas. The observations in this experiment confirmed that the proposed could operate in the 5G NR n46 (5.15–5.925 GHz), n47 (5.855–5.925 GHz), n77 (3.3–4.2 GHz), n78 (3.3–3.8 GHz), and the n79 (4.4–5 GHz) bands. Moreover, it exhibited a wide impedance bandwidth (dB magnitude of S11) of 101% in the 2.3–7 GHz frequency range, high isolation (dB magnitude of S21), low envelope coefficient correlation (ECC), gain of over 5 dB, and average radiation efficiency of 87.19%, which verified its suitability for application in sub-6 GHz 5G wireless communication systems.

A Compact Planar Dual-Band Multiple-Input and Multiple-Output Antenna with High Isolation for 5G and 4G Applications.

Featured Application The proposed dual-band MIMO antenna can be a good candidate for 5G and 4G applications. In this paper, a compact planar dual-band multiple-input and multiple-output (MIMO) antenna with high isolation is presented to satisfy the increasing requirements of wireless communication. The proposed antenna array consists of two identical radiating elements which are fed through micro-strip lines. A rectangular micro-strip stub with defected ground plane is employed to achieve a high isolation which is less than −15 dB between the two antenna elements. The size of the entire MIMO antenna is 32 × 32 × 1.59 mm3, which is printed on an FR4 substrate. The proposed MIMO antenna is optimized to operate in 2.36–2.59 GHz and 3.17–3.77 GHz bands, which can cover the fifth-generation (5G) n7 (2.5–2.57 GHz) and the fourth-generation (4G) Long Term Evolution (LTE) band 42 (3.4–3.6 GHz). The proposed MIMO antenna is feasible for the 5G and 4G applications.

Design of a Compact Dual-Band MIMO Antenna System with High-Diversity Gain Performance in Both Frequency Bands.

A compact four-element dual-band multiple-input and multiple-output (MIMO) antenna system is proposed to achieve high isolation and low channel capacity loss. The MIMO antenna was designed and optimized to cover the dual-frequency bands; the first frequency band is a wide band, and it covers the frequency range of 1550–2650 MHz, while the other frequency band covers the 3350–3650 MHz range. The measured wide-band impedance bandwidths of 1.1 GHz and 300 MHz were achieved in the lower and upper frequency bands, respectively. The proposed structure consists of four novel antenna elements, along with a plus-sign-shaped ground structure on an FR4 substrate. The overall electrical size of the whole dual-band MIMO antenna system is (W) × (L) × (H) for the lower frequency band. It achieved greater than 10 and 19 dB isolation in the lower and upper frequency bands, respectively. The antenna system accomplished an envelope correlation coefficient of in the lower frequency band, while it achieved in the higher frequency band. The computed channel capacity loss remained less than almost 0.4 bits/s/Hz in both frequency bands. Therefore, it achieved good performance in both frequency bands, with the additional advantage of a compact size. The proposed MIMO antenna is suitable for compact handheld devices and smartphones used for GSM (Global System for Mobiles), UMTS (Universal Mobile Telecommunications Service), WCDMA (Wideband Code Division Multiple Access), LTE (Long Term Evolution), 5G sub-6 GHz, PCS (Personal Communications Service), and WLAN (wireless local area network) applications.

Epoxy based on low profile MIMO antenna for cellular systems

The multiple band of antenna has proposed in this article. It consists of two element structure, which represents as Multiple Input and Multiple Output (MIMO) mechanism. It provides the isolation structure and reduces the mutual coupling between the ports on it. It has achieved the sufficient the isolation and return losses of 40 dB and 17 dB respectively. It has included the compact planer profile with spectrum of 1–3 GHz. It has been provided the good Quality of Service (QoS) without degradation of bandwidth and transmission power. Hence these design parameters have validated with their simulation results.

Design and analysis of 4 × 4 MIMO antenna with DGS for WLAN applications

AbstractIn this paper, a low profile 4 × 4 multiple input and multiple output (MIMO) antenna is proposed and designed for wireless local area network (WLAN) application using a square split-ring resonator. Initially, a single square-patch antenna is designed with square-shaped split-ring slot. Subsequently, the two-element MIMO antenna is designed and it is extended to four-element MIMO antenna. Finally, the defected ground structure (DGS) is implemented in order to enhance antenna performance. The antenna elements are placed opposite to each other. The mutual coupling between the antennas elements is reduced by DGS. The proposed single, two and four-element antennas operate at 5.8 GHz for WLAN. The overall performance is measured in terms of S parameter, radiation pattern, and envelope correlation coefficient. The simulated results are verified through measurements. The simulated and measured results demonstrate that the proposed 4 × 4 MIMO antenna is the most suitable for WLAN applications.