5G Applications Research Articles

Tri-band antenna with metasurface-based ground plane for Sub-6 GHz 5G and 6G WPT applications

In this paper, a spiral-shaped metamaterial-loaded rhombic slotted microstrip patch antenna is investigated for Sub-6 GHz 5G and 6 GHz tri-band applications. A 1.524 mm thick Rogers RO4003 substrate (ϵr = 3.55, LosTanδ = 0.0027) opts for the antenna design. A partially grounded mechanism is implemented to control the operating frequencies of the antenna. A 5×5 triangular unit cell metasurface is deposited beside the partial ground plane to enhance the impedance bandwidth as well as to improve the impedance matching. A G-shaped metallic structure enclosed within the rhombic slotted antenna helps in creating circular polarization (CP) properties. The presented antenna resonates at 3.28 GHz (Mid-range Sub 6 GHz 5G band), 4.94 GHz (Upper range Sub 6 GHz 5G band), and 6.92 GHz (Sub 6 GHz 6G Band) frequencies. The maximum gain offered by the antenna is 8.81 dBi. Also, the developed antenna offers CP characteristics in all three operating bands with wide axial ratio (AR) bandwidth characteristics above 400 MHz in both the first and third operating bands. The radial characteristics of the proposed antenna show its capability of receiving EM signals from all directions as desired for a WPT system. For validation purposes, a prototype is fabricated and characterized as well.

Design of high gain and wideband circular patch antenna based on DGS for 28 GHz 5G applications

Design of high gain and wideband circular patch antenna based on DGS for 28 GHz 5G applications

Creation of a soft circular patch antenna for bio-medical applications for 5G at frequency 2.45 GHz

In the medical field, efforts are currently focused on the development of devices implanted in the human body, to build a high-performance infrastructure and a working tool adapted to patients' needs. One such implanted device is the pacemaker, which is playing an increasingly important role in today's medicine. Moreover, in the general context of medical activities, we speak of telemedicine. This involves the transmission of medical information (images, reports, recordings) via antennae implanted or fixed on the human body, to obtain a remote diagnosis, specialist advice, constant patient monitoring, and a therapeutic decision. This paper presents a study and design of a circular flexible patch antenna with half-circle-shaped gaps on its sides and a slot on the opposite part of its feed; it is implemented on a bio-sourced type substrate intended for industrial, scientific, and medical applications. In addition, it is fed by microstrip technology, which features notches for impedance matching. In addition, this antenna offers improved performance compared with the literature.

Multi-frequency composite wearable antenna for wireless communications

This paper proposes a multi-band composite wearable antenna for wireless communication, which uses a monopole structure as the radiating body and achieves multi-band characteristics through slit-loading and multi-branching methods. A polymer composite substrate with high dielectric constant and low dielectric loss was prepared using in situ polymerization, and the optimal dielectric constant and loss angle tangent were obtained by controlling the coating ratio of melamine formaldehyde resin to carbon nanotubes (MWCNTs) and the filler doping rate to achieve miniaturization of the antenna. Comparative experimental results show that the obtained composites have high flexibility and good dielectric properties. The antenna operates in the frequency bands of 2.21–2.52 GHz, 3.07–3.87 GHz, and 4.36–6.03 GHz, which cover the frequency bands of WLAN and WiMAX and 5G applications. The antenna was fabricated and tested, and its performance roughly matched the simulation results. Meanwhile, the antenna has passed the SAR safety test and maintained a stable performance under different curvatures, so it has potential applications in the wireless communication system.

Design of high selectivity tri-band bandpass filter based on triple transversal transmission path

By utilizing transversal signal interference concepts, a tri-band bandpass filter with a triple transmission path is proposed in this paper. Triple transversal transmission paths are respectively constructed with the employ of parallel coupled stub loaded resonator, microstrip gap coupled line and parallel coupled shorted stub loaded resonator. Based on the triple transversal transmission path, nine transmission poles (TPs) are excited; therefore, triple independently controllable wideband passbands are realized. Due to the transversal cancellation between transmission paths with the virtual short mechanism of each transmission path, seven transmission zeros (TZs) can be excited and managed. Therefore tri-wideband characteristics with high selectivity and high band-to-band isolation can be obtained by properly adjusting the TPs and TZs. To further demonstrate the proposed design methodology, a prototype tri-wideband bandpass filter operating at 1.93/3.52/5.11 GHz with fractional bandwidth of 11.8 %, 19.8 % and 22.8 % for LTE, WiMAX, Wi-Fi and 5G applications is synthesised. The presented tri-wideband bandpass filter is designed, manufactured and measured. The measured results agree well with theoretical predictions, which exhibit superior performance such as sharp shirts, high band-to-band isolation compact size and ideal out-of-band suppression.

Printed Dual Band Antenna with Parasite Elements for LTE and 5G Applications

A printed antenna for long-term evolution (LTE) band (1.71–1.755 GHz) and 5G band (3.3–3.8 GHz) has been investigated in this article. A balanced feeder line is employed to feed the radiating element at the 5G band of operation, which becomes a radiator at the LTE band. The measured reflection coefficient (S11≤−10 dB) bandwidth is 6% (LTE band: 1.67–1.776 GHz) and 30.76% (5G band: 2.875–3.92 GHz). This antenna radiates with a gain of 3.25 dBi at the LTE band in the broadside and 6.5dBi at the 5G band in the end-fire direction. An open-ended tuning stub is used to tune out the reactance of the radiating element to enhance its radiation and act as a reflector to enhance the directivity in the 5G band. The printed parasite strip forces the beam towards the axial direction (end-fire) and enhances the gain in the 5G band. Both bands form an orthogonal radiation pattern. This antenna can also be utilized for WiMAX (3.5 GHz) band applications.

A deep learning based approach for image retrieval extraction in mobile edge computing

AbstractDeep learning has been widely explored in 5G applications, including computer vision, the Internet of Things (IoT), and intermedia classification. However, applying the deep learning approach in limited-resource mobile devices is one of the most challenging issues. At the same time, users’ experience in terms of Quality of Service (QoS) (e.g., service latency, outcome accuracy, and achievable data rate) performs poorly while interacting with machine learning applications. Mobile edge computing (MEC) has been introduced as a cooperative approach to bring computation resources in proximity to end-user devices to overcome these limitations. This article aims to design a novel image reiterative extraction algorithm based on convolution neural network (CNN) learning and computational task offloading to support machine learning-based mobile applications in resource-limited and uncertain environments. Accordingly, we leverage the framework of image retrieval extraction and introduce three approaches. First, privacy preservation is strict and aims to protect personal data. Second, network traffic reduction. Third, minimizing feature matching time. Our simulation results associated with real-time experiments on a small-scale MEC server have shown the effectiveness of the proposed deep learning-based approach over existing schemes. The source code is available here: https://github.com/jamalalasadi/CNN_Image_retrieval.

A dual ultra-wideband rectenna with a compact conical antenna for RF energy harvesting from S and C bands

The current research introduces a novel dual ultra-wideband rectenna that has been specifically devised for the S and C bands. The rectenna configuration being presented demonstrates the potential to efficiently capture energy from 1.5 GHz to 4.65 GHz, and 5.55 GHz–7.85 GHz. It is noteworthy to mention that the bandwidths (BW) corresponding to these frequency ranges are 3.15 GHz and 2.3 GHz, correspondingly. The envisioned rectenna is designed to cater to a selection of five distinct commercial bands. The frequencies under consideration include 1.8 GHz, UTMS 2.1 GHz, 5G 3.5 GHz, 4.5 GHz, and 5.8 GHz, which fall within the mid band range for 5G technology. Notably, the extended S-band and C band are also included within this range, catering specifically to 5G applications. For the purpose of rectification, a solitary HSMS 2850 Schottky diode has been selected. The maximum recorded Conversion Efficiency (CE) achieved at 1.8 GHz, 2.1 GHz, 3.5 GHz, 4.5 GHz, and 5.8 GHz corresponds to CE values of 67 %, 65 %, 77 %, 71 %, and 71 %, respectively. These CE measurements were obtained under varying input power levels (IPL) of −6 dBm, 4 dBm, 4 dBm, 2 dBm, and 9 dBm, respectively. The rectenna under consideration is designed to operate across five distinct frequency bands. Notably, the CE exceeds 65 % across all of these frequency bands. Consequently, the rectenna exhibits a higher output power. As a result, this modification makes it appropriate for supplying energy to low-power electronic equipment.

Development of Wearable Textile MIMO Antenna for Sub-6 GHz Band New Radio 5G Applications.

In this paper, an irregular octagonal two-port MIMO patch antenna is designed specifically for New Radio (NR) 5G applications in the mid-band sub-6 GHz. The proposed antenna comprises an irregularly shaped patch antenna equipped with a regular 50-ohm feed line and a parasitic strip line antenna, and is partially grounded. Jeans material serves as a substrate with an effective dielectric constant of 1.6 and a thickness of 1 mm. This material is studied experimentally. The proposed antenna design undergoes analysis and optimization using the ANSYS HFSS tool. Furthermore, the design incorporates the influence of the slot on both the ground plane and the parasitic strip line to optimize performance, enhance isolation, and improve impedance matching among antenna elements. The dimensions of the jeans substrate are 40 mm × 50 mm. The simulated impedance bandwidth ranged from 3.6 GHz to 7 GHz and the measured bandwidth was slightly narrower, from 4.35 GHz to 7 GHz. The simulation results demonstrated an isolation level greater than 12 dB between antenna elements, while the measured results reached 28.5 dB, and the peak gain for this proposed antenna stood at 6.74 dB. These qualities made this proposed antenna suitable for various New Radio mid-band 5G wireless applications within the sub-6 GHz band, such as N79, Wi-Fi-5/6, V2X, and DSRC applications.

Ni-Co Complex Ionic Synergistically Modifying Octahedron Lattice of Cordierite Ceramics for the Application of 5G Microwave-Millimeter-wave Antennas.

In this work, phase-pure Mg1.8(Ni1-xCox)0.2Al4Si5O18 (0 ≤ x ≤ 1) ceramics were synthesized by a high-temperature solid-state method. On the basis of Rietveld refinement data of X-ray powder diffraction and Phillips-Vechten-Levine theory, the atomic ionicity, lattice energy, and bond energy of the compound were calculated to explore their influence on the microwave dielectric properties of ceramics. The Mg1.8Ni0.1Co0.1Al4Si5O18 (x = 0.5) ceramic exhibited the best microwave dielectric properties: εr = 4.44, Qf = 73 539 GHz@13 GHz, and τf = -23.9 ppm/°C. (Ni1-xCox)2+ complex ionic doping, compared with only Ni2+ or Co2+, is beneficial for improving the symmetry of [Si4Al2O18] hexagonal rings and reducing distortion. Subsequently, 8 wt % TiO2 was added to Mg1.8Ni0.1Co0.1Al4Si5O18, resulting in a near-zero τf and high Qf values for the composite ceramic, with εr = 5.22, Qf = 58 449 GHz@13 GHz, and τf = -2.06 ppm/°C. Finally, a 5G millimeter-wave antenna with a central operating frequency of 25.52 GHz was designed and fabricated using the Mg1.8Ni0.1Co0.1Al4Si5O18-8 wt % TiO2 ceramics. Operating in the 24.7-26.0 GHz range, it demonstrated favorable radiation characteristics with a simulated efficiency of 85.2% and a gain of 4.58 dBi. The antenna's performance confirms the high potential of the cordierite composite for application in 5G communication systems.

New Compact Broadband SRR Loaded Antenna Pattern for 5G Applications

New Compact Broadband SRR Loaded Antenna Pattern for 5G Applications

Laser-assisted screen-printing of graphene folded reflectarray antenna for millimeter-wave applications

Antennas operating at high frequency bands are sought after for applications in 5G, satellite, radar, and other communication systems. Graphene, a two-dimensional material known for its exceptional conductivity, mechanical strength, and chemical stability, is anticipated to serve as a viable substitute for copper in antenna applications. However, researches on graphene antennas at millimeter-wave and higher frequencies are mainly limited to theory and simulation, due to the fabrication challenges of achieving high-precision graphene patterns. Herein, we present the design and fabrication of a graphene folded reflectarray antenna (FRA) operating at millimeter-wave. The FRA is fabricated using screen-printing of graphene ink on an RT5880 substrate, followed by laser engraving for precise patterning. The main reflector has 918 patch units, and the polarizing grids have line widths and spacings of 100 μm. Measurements demonstrate that the antenna has a realized peak gain of 21.37 dBi at 37.5 GHz. The radiation patterns show a 3 dB beamwidth of 6° and 4° in the E-plane and H-plane respectively, with cross-polarization more than −18 dB. The laser-assisted screen-printing method provides a feasible strategy for the precision manufacture of graphene communication devices.

A multi-radio antenna system for Cognitive Radio(CR), 5G, WLAN and UWB MIMO applications

This article presents a multi-radio antenna system for Cognitive Radio (CR), NB MIMO (5G, WLAN), and UWB MIMO applications by combining independent antennas into a single system. The proposed multi-radio antenna system comprises three independent antennas: the CR antenna system, which consists of a UWB sensing radiator and two narrow band communication antennas; the UWB MIMO antenna system, which comprises a two-element UWB MIMO antenna; and the NB (5G, WLAN) NB antenna system, which consists of a two-element NB antenna. The UWB radiator functions over a bandwidth of 3–12 GHz for CR sensing and UWB MIMO operations, while the NB antennas operate at 3.3, 3.5, 5, 5.5, and 8 GHz for CR communication and NB MIMO communication. Mutual coupling between MIMO radiators is achieved by placing the radiators orthogonal to each other and a parallel line stub. The reflection coefficient, gain, efficiency, and radiation pattern of an antenna were studied. Furthermore, the MIMO performance of UWB MIMO and NB MIMO antenna systems is evaluated using MIMO parameters such as mutual coupling, envelope correlation coefficient, Total active reflection coefficients (TARC), and channel capacity loss (CCL).

Multiband Frequency Compact Patch Antenna for 5G Applications

The design of a multi-band microstrip patch antenna, with a focus on the frequencies of 27.4GHz, 46GHz, and 58.2GHz, is described in this work. The antenna arrangement consists of a rectangular patch with an incorporated 0.088mm x 2mm rectangular slit. The antenna is based on a 3.285mm×7.235mm Roger RT/duroid 5880(tm) substrate with a dielectric constant of 4.4. It is fed via a 3.4mm×4.1mm microstrip-fed rectangular patch. The antenna operates in multi-band mode, as demonstrated by the simulation results, which show that it can reach respective bandwidths of 19 GHz and 12 GHz. At 27.4 GHz, 46 GHz, and 58.3 GHz, the return loss values are roughly -35.5 dB, -13.35 Db, and - 26.9 dB. The measured gains at 27.4GHz, 46GHz, and 56.6GHz are 6.04dB, 3.55dB, and 10.04dB, respectively. The outcomes produced by this suggested antenna should meet the requirements for 5G wireless communication applications and automotive radar systems.

A Broadband Three-Way Series Doherty Power Amplifier with Deep Power Back-Off Efficiency Enhancement for 5G Application

This article presents a new broadband three-way series Doherty power amplifier (DPA) topology, which enables a broadband output power back-off (OBO) efficiency enhancement of up to 10 dB or higher. The proposed DPA topology achieves Doherty load modulation and three-way power combining through a transformer, which requires only a low coupling factor, thus facilitating its implementation in double-sided PCBs or monolithic microwave integrated circuit (MMIC) processes. The design equations for the proposed DPA topology are proposed and analyzed in detail. A proof-of-concept PA at the 2.1–2.8 GHz band using commercial GaN transistors was designed and fabricated to validate the proposed concept. Within the operating frequency band, it achieves a saturated output power (Psat) of 44.5–46.5 dBm with a peak drain efficiency (DE) of 60–72%, and 43–52% DE at 10 dB OBO. Moreover, under a 20 MHz long-term evolution (LTE)-modulated signal, the PA demonstrates a 36.8–37.5 dBm average output power (Pavg) and 47–53% average drain efficiency (DEavg). Notably, the adjacent channel leakage ratio (ACLR) is as low as −35–−28.2 dBc without any digital predistortion (DPD).

An inverted U‐shaped merged stubs hexa‐band 4‐element MIMO antenna for advanced wireless applications

SummaryA four‐element hexa‐band inverted U‐shaped merged stubs miniaturized Multiple‐Input Multiple‐Output (MIMO) radiator, operating in 2.10–2.17 GHz for 3G (2.17 GHz) band, 2.52–2.60 GHz for 4G (2.5 GHz) band, 3.31–3.46 GHz for 5G (3.4 GHz [n77 and n78]) bands, 3.66–3.72 GHz for 5G (3.7 GHz [n77 and n78]) bands, 4.53–4.62 GHz for 5G (4.5 GHz [n79]) band, and 5.15–6.02 GHz for 5.5 GHz WLAN bands, is developed. The radiator and ground planes comprise of multiple inverted U‐shaped stubs and slots to form the proposed configuration having overall compact dimensions of 62 × 62 × 1.6 mm3. The peak gain and radiation efficiency of the antenna are found to be 1.31 dBi and 77.48% at 2.17 GHz, 0.98 dBi and 63.3% at 2.55 GHz, 2.9 dBi and 71.13% at 3.38GHz, 1.6 dBi and 66.68% at 3.68 GHz, 2.58 dBi and 77% at 4.57 GHz, and 3.27 dBi and 68.68% at 5.52GHz. The arrangement of four antenna elements is orthogonal (rotationally symmetric) to minimize the mutual coupling, and hence, a minimum isolation of more than 15 dB is noted between all the antenna ports. Furthermore, Envelope Correlation‐Coefficient (ECC) in desired bands is lower than 0.012. Channel Capacity‐Loss (CCL) and Diversity‐Gain (DG) are also good with 0.015 bits/s/Hz and 9.96 dB, respectively. The fabricated structure measurement results agree well with simulation outcomes. These facts result that the proposed MIMO structure is a promising module for the usage in WLAN, 4G, and 5G band applications.

Dual‐ and triple‐passband coupled‐complementary FSSs based on the four‐arms star geometry

AbstractThe authors propose a system of closely coupled‐complementary frequency‐selective surfaces (FSSs) based on the four‐arms star geometry with dual‐ and triple‐passbands responses for 5G applications. Four complementary structure configurations are presented, and depending on the chosen configuration, the structure can create two or three transmission bands in one or both polarisations of the electromagnetic waves. The designed FSSs are compact and have stable behaviour at different incident angles. The complementary FSS passes signals around 2.6 and 6.2 GHz, and a structural offset allows the transmission at a third frequency (4.2 GHz). To validate the proposed designs, four prototypes are fabricated and measured. Numerical and experimental characterisations are in good agreement.

Design and fabrication of a microstrip triplexer with wide flat channels for multi-band 5G applications.

In this paper, a new microstrip triplexer is designed to work at 2.5 GHz, 4.4 GHz and 6 GHz for mid-band 5G applications. All channels are flat with three low group delays (GDs) of 0.84 ns, 0.75 ns and 0.49 ns, respectively. Compared to the previously reported works, the proposed triplexer has the minimum group delay. The designed triplexer has 18.2%, 13.7%, 23.6% fractional bandwidths (FBW%) at 2.5 GHz, 4.4 GHz and 6 GHz, respectively. The obtained insertion losses (ILs) are low at all channels. These features are obtained without a noticeable increase in the overall size. A novel and simple resonator is used to design the proposed triplexer, which includes two pairs of coupled lines combined with a shunt stub. A perfect mathematical analysis is performed to find the resonator behavior and the layout optimization. The type of shunt stub is determined mathematically. Also, the smallness or largeness of some important physical dimensions is determined using the proposed mathematical analysis. Finally, the designed triplexer is fabricated and measured, where the measurement results verify the simulations.

Circumferential slots based decoupled wideband MIMO antenna for 5G and sub-6 GHz applications

This paper investigates a small size 2 × 2 wideband multiple input multiple output (MIMO) antenna covering frequency band of 2.61 to 5.52 GHz. The antenna structure consists of elliptical ring patch with multiple circumferential slots. The edge-to-edge separation between the patches are kept 3.6 mm with volumetric dimensions of 30 × 46 × 1.6 mm3. The narrow slits are etched in the tapered ground plane to obtain the wideband characteristics. The electromagnetic coupling is improved more than 16 dB by employing the neutralization technique. The measured average gain and radiation efficiency of the proposed antenna are above 2.61dBi and 83.54%, respectively across the operating band. In addition to that, the important MIMO diversity parameters are investigated. The group delay and signal analysis in different orientations are also studied to ensure the quality performance of the antenna. The proposed MIMO antenna is simulated using CST microwave studio and further validated with the measurements. In addition to that, the parallel and orthogonal configuration of 4 × 4 MIMO antennas are analyzed by extending the proposed 2 × 2 MIMO design. The 4-port MIMO antennas exhibit the operating frequency bands varying from 2.80 to 5.58 GHz and 3.4 to 5.52 GHz, respectively for parallel and orthogonal MIMO configurations. The diversity parameters of 4-port MIMO antennas are calculated and compared with the measured results to verify its practical applications. Finaly, the SAR analysis of the antenna is presented at 3.08 and 5.20 GHz for 1/10 g tissues and are found 0.111/0.106 and 0.079/0.063 W K−1g−1, respectively. The proposed MIMO antenna designs are suitable for modern high-speed communication for 5G and sub-6 GHz frequency bands.

RBFNN-based UWB 4×4 MIMO Antenna Design with Compact Size, High Isolation, and Improved Diversity Performance for Millimeter-Wave 5G Applications

Abstract The millimeter-wave spectrum has emerged as a compelling solution to address the pressing need for high-datarate
capabilities in the development of 5G technology systems. Spanning between 20 GHz and 40 GHz, this spectrum
encompasses several prominent frequency bands crucial for advancing 5G applications. In light of this, our study
presents a thorough investigation into the design and performance of a compact cross-shaped slot broadband antenna,
complemented by a 4×4 Multiple-InputMultiple-Output (MIMO) configuration tailored for 5G operations at
28 GHz. The primary objective of this study is to develop an antenna system capable of achieving an extended bandwidth
ranging from 20 GHz to 40 GHz, effectively covering the crucial frequency bands essential for 5G millimeterwave(
mmWave) operations. To accomplish this, the optimization of antenna performance is meticulously carried out
using the Radial Basis FunctionNeuralNetworks (RBFNN) model. The RBFNNmodel serves as a robust tool for establishing
the intricate relationship between antenna dimensions, resonant frequency, and bandwidth. Subsequently,
the developed RBFNN model is employed to predict optimal antenna dimensions, ensuring resonance at 28 GHz and
meeting specified bandwidth targets. The single antenna is designed with a rectangular patch and a cross-shaped
slot and is constructed on the low loss Rogers RT Duroid 5880 substrate. This design reaches an outstanding bandwidth
of 19.5 GHz, and exhibits excellent radiation characteristics, with a high radiation efficiency of up to 99% and a
corresponding gain of 5.75 dB. The antenna’s design and performance are rigorously designed using HFSS software,
which is then compared to the results acquired using CST software. In addition, the proposed MIMO configuration
offers excellent performance in terms of key features such as small size (16 × 16.2 mm2), very wide bandwidth of 20
GHz, good gain of 6.75 high isolation exceeding 35 dB, and significant improvements in diversity performance measures
such as Envelope Correlation Coefficient (ECC), Diversity Gain (DG), Channel Capacity Loss (CCL), Total Active
Reflection Coefficient (TARC), and Mean Effective Gain (MEG). The potential of the proposed MIMO configuration
for high-speed applications is particularly remarkable. Practical verification of the MIMO configuration is carefully
carried out by fabrication andmeasurement. Experimental results strongly confirmthe effectiveness of the proposed
antenna design, establishing it as a competitive challenger for 5G technology.