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Sub-terahertz communications (100–300 GHz) are explored today as a candidate technology to enable extremely high-rate, low-latency data services and high-resolution sensing in beyond-fifth-generation (beyond-5G) wireless networks. However, these sub-terahertz wireless systems will often have to operate in the near field, where the signal propagation does not follow canonical far-field models, including the commonly used free space path loss equation. Instead, the signal propagation in the near field follows more complex patterns that are not well-captured with analytical far-field models standardized for 5G research. Moreover, state-of-the-art beamforming solutions exploited heavily in fourth-generation (4G) and 5G networks are notably less efficient in the near field. In this article, the near-field sub-terahertz channel is accurately measured and analyzed. In addition to state-of-the-art beamforming, the article also analyzes the sub-terahertz channel measurements when using near-field-specific Bessel beams that demonstrate fewer power fluctuations in the near field in addition to higher focusing gain. Novel distance-centric and angle-centric dependencies reported in this article may serve as a reference when developing next-generation channel models for sixth-generation (6G) and beyond-6G near-field sub-terahertz wireless systems. [ABSTRACT FROM AUTHOR]

At present, social networks have become an indispensable medium in people's daily life and work. However, concerns about personal privacy leakage and identity information theft have also emerged. Therefore, a communication network system based on network slicing is constructed to strengthen the protection of communication network privacy. The chameleon hash algorithm is used to optimize attribute-based encryption and enhance the privacy protection of communication networks. On the basis of optimizing the combination of attribute encryption and homomorphic encryption,, a communication network privacy protection method using homomorphic encryption for network slicing and attribute is designed. The results show that the designed network energy consumption is low, the average energy consumption calculation is reduced by 8.69%, and the average energy consumption calculation is reduced by 14.3%. During data transmission, the throughput of the designed network can reach about 700 Mbps at each stage, which has a high efficiency.. The above results demonstrate that the designed communication network provides effective privacy protection. Encrypted data can be decrypted and tracked in the event of any security incident. This is to protect user privacy and provide strong technical support for communication network security. [ABSTRACT FROM AUTHOR]

In this paper, a low‐profile, high‐gain filtering antenna is proposed and developed for n‐77 (3300–4200 MHz) and n‐78 band (3300−3800 MHz) applications. The suggested filtering antenna is derived from a circular patch antenna. To efficiently reduce the harmonics, in the lower and upper stopbands, a pair of sectoral arcs and rectangular slots is etched out from the driven circular patch. Furthermore, the resultant structure is surrounded by a ring split at three different locations. Simulation studies reveal that this ring with three sectors is coupled with a driven patch and is highly responsible for extending the impedance bandwidth in the passband. This coupling also contributes to an extranull in the upper stopband region. In order to validate the simulated results, a prototype is fabricated, tested, and found that the measured results are consistent with the simulated one. The suggested filtering antenna, with a low profile of 0.0194λ0, demonstrates a wide fractional bandwidth of 10.2% ranging from 3.52 to 3.90 GHz, centred at 3.7 GHz. The maximum peak gain of 7.68 dB is achieved within the passband. Three configurable radiation nulls, first at 3.36 GHz, near the lower band edge; second at 4.04 GHz; and third at 4.24 GHz, near the upper band‐edge frequencies, are generated to achieve fine out‐of‐band suppression levels. [ABSTRACT FROM AUTHOR]

Beyond 5G networks provide solutions for next-generation communications, especially digital twins networks (DTNs) have gained increasing popularity for bridging physical and digital space. However, current DTNs pose some challenges, especially when applied to scenarios that require efficient and multimodal data processing. Firstly, current DTNs are limited in communication and computational efficiency, since they require to transmit large amounts of raw data collected from physical sensors, as well as to ensure model synchronization through high-frequency computation. Second, current models of DTNs are domain-specific (e.g. E-health), making it difficult to handle DT scenarios with multimodal data processing requirements. Finally, current security schemes for DTNs introduce additional overheads that impair the efficiency. Against the above challenges, we propose a large language model (LLM) empowered DTNs framework, LLM-Twin. First, based on LLM, we propose digital twin semantic networks (DTSNs), which enable more efficient communication and computation. Second, we design a mini-giant model collaboration scheme, which enables efficient deployment of LLM in DTNs and is adapted to handle multimodal data. Then, we designed a native security policy for LLM-twin without compromising efficiency. Numerical experiments and case studies demonstrate the feasibility of LLM-Twin. To our knowledge, this is the first to propose an LLM-based semantic-level DTNs. [ABSTRACT FROM AUTHOR]

The unique combination of the high data rates, ultra-low latency, and massive machine communication capability of 5G networks has facilitated the development of a diverse range of applications distinguished by varying connectivity needs. This has led to a surge in data traffic, driven by the ever-increasing number of connected devices, which poses challenges to the load distribution among the network cells and minimizes the wireless network performance. In this context, maintaining network balance during congestion periods necessitates effective interaction between various network components. This study emphasizes the crucial role that mobility management plays in mitigating the uneven load distribution across cells. This distribution is a significant factor impacting network performance, and effectively managing it is essential for ensuring optimal network performance in 5G and future networks. The study investigated the complexities associated with congested cells in wireless networks to address this challenge. It proposes a Dynamic Distance-based Load-Balancing (DDLB) algorithm designed to facilitate efficient traffic distribution among contiguous cells and utilize available resources more efficiently. The algorithm reacts with congested cells and redistributes traffic to its neighboring cells based on specific network conditions. As a result, it alleviates congestion and enhances overall network performance. The results demonstrate that the DDLB algorithm significantly improves key metrics, including load distribution and rates of handover and radio link failure, handover ping-pong, and failed attached requests. [ABSTRACT FROM AUTHOR]

In order to implement the fifth generation (5G) communication system for a large number of users, the governments of many countries nominated the low 5G frequency band between 3.3 and 4.3 GHz. This paper proposes a wideband RFPA by designing the input matching network (MN) and output MN of the device using the simplified real frequency technique (SRFT) and the harmonic tuning network. The load-pull and source-pull is applied at multiple points for 100 MHz intervals over the bandwidth to obtain the optimum impedances at the output and input of the 10W Gallium Nitride (GaN) Cree CGH40010F device. To verify the design, the RFPA is simulated, and the performance is measured between 3.3 and 4.3 GHz. According to experimental findings, the measured drain efficiency (DE) throughout the whole bandwidth ranged from 57.5 to 67.5% at the output power of 40 dBm. Moreover, at the 1 dB compression point between 39.2 and 42.2 dBm output power, the drain efficiency (DE) achieves a high value of 81.2% with an output power of 42.2 dBm at a frequency of 3.3 GHz. The RFPA can obtain a maximum gain of 12.4 dB at 3.5 GHz. The linearity of the RFPA with a two-tone signal is measured and the value is less than -22 dBc all over the band. [ABSTRACT FROM AUTHOR]

Introduction: The emergence of electromagnetic wave pollution as a new form of pollution in human society is attributed to the advancements in communication technology and the electronic information business. In addition to harming priceless electronic equipment, these electromagnetic radiation and interference issues brought on by electrical and electronic devices have a major negative influence on human productivity and wellbeing. The secret to getting rid of electromagnetic radiation interference (EMI) and improving performance is electromagnetic shielding technology. Metamaterial absorber is a type of metamaterial that absorb EMI radiation. The benefits of metamaterial absorbers include their lightweight, simple construction, and excellent absorptivity. Methods: This paper proposes a novel metamaterial absorber for EMI radiation absorption. It consists of dielectric layers, metamaterial shielding layer and transmission line. The reflection of radiation is reduced by miniaturization of metamaterials. Results and Discussion: Simulation results show that the proposed design has better performance as compared to existing methods. The operating frequency range is from 23.1 to 28.3 GHz. The values of S21 with and without shielding are -5 dB and -0.05 dB, and the shielding effectiveness is 10.10 dB and a maximum of 12.63 dB. [ABSTRACT FROM AUTHOR]

In the current 5G vehicle network system, there are security issues such as wireless intrusion, privacy leakage, and remote control. To address these challenges, an improved lightweight anonymous authentication key negotiation scheme based on certificate-less aggregate signatures is proposed and its security and efficiency are analyzed. The result shows that the scheme can offer security attributes including anonymity, traceability, and revocability, as well as effective identity authentication, and it can resist forgery attacks, man-in-the-middle attacks, tampering attacks, and smart card loss attacks. Moreover, compared with similar schemes, it possesses superior security and more efficient computational efficiency and less communication overhead, thereby being more appropriate for high-speed, large-capacity, low-latency, and resource-constrained 5G vehicle network application scenarios. [ABSTRACT FROM AUTHOR]

With the rapid development of 5G, UAV, and military communications, the data volume obtained by the non-cooperative perception system has increased exponentially, and the distributed system has become the development trend of the non-cooperative perception system. The data distribution service (DDS) produces a significant effect on the performance of distributed non-cooperative perception systems. However, the traditional DDS discovery protocol has problems such as false positive misjudgment and high flow overhead, so it can hardly adapt to a large multi-node distributed system. Therefore, the design of a DDS discovery protocol for large distributed system is technically challenging. In this paper, we proposed SDP-DCBF-SFF, a discovery protocol based on the Dynamic Counter Bloom Filter (DCBF) and Second Feedback Filter (SFF). The proposed discovery protocol coarsely filters the interested endpoints through DCBF and then accurately screens the uninterested endpoints through SFF to eliminate the connection requests of false positive endpoints and avoid extra flow overhead. The experimental results indicate that the proposed discovery protocol could effectively reduce the network overhead, and eliminate the false positive probability of endpoints in small, medium, large, and super large systems. In addition, it adopts the self-adaptive extension mechanism of BF to reduce the reconfiguration delay of BF and achieve the smallest system transmission delay. Therefore, the proposed discovery protocol has optimal comprehensive performance and system adaptability. [ABSTRACT FROM AUTHOR]

One of the key features of mobile networks in this age of mobile communication is seamless communication. Handover (HO) is a critical component of next-generation (NG) cellular communication networks, which requires careful management since it poses several risks to quality-of-service (QoS), including a decrease in average throughput and service disruptions. Due to the dramatic rise in base stations (BSs) and connections per unit area brought about by new fifth-generation (5G) network enablers, such as Internet of things (IoT), network densification, and mm-wave communications, HO management has become more challenging. The degree of difficulty is increased in light of the strict criteria that were recently published in the specifications of 5G networks. In order to address these issues more successfully and efficiently, this study has explored and examined intelligent HO optimization strategies using machine learning models. Furthermore, the significant goal of this review is to present the state of cellular networks as they are now, as well as to talk about mobility and home office administration in 5G alongside the overall features of 5G networks. This work presents an overview of machine learning methods in handover optimization and of the various data availability for evaluations. In the final section, the challenges and future research directions are also detailed. [ABSTRACT FROM AUTHOR]

This paper presents a circularly polarized hybrid cylindrical dielectric resonator antenna (HCDRA) over a modified Minkowski unit-cell-based metasurface for 5G n79 band (4.4–5 GHz) and IEEE 802.11n WLAN (5 GHz) applications. The location of the perturbed probe feed mechanism and the asymmetric nature of the metasurface are the factors that influence the circularly polarized (CP) radiation within the DR element. The magnitude of E-field distribution and parametric study of the antenna to obtain the optimized feed location are the pieces of evidence of CP radiation. The return loss (RL) and axial ratio (AR) bandwidths produced by the proposed antenna are 1.837 GHz and 750 MHz with a peak gain of 7.04 dBic. The gain obtained is more than 5 dBic across the offered bandwidth of the proposed antenna. The proposed antenna is fabricated and tested in an anechoic chamber for measured results, and these results closely match with the simulation results. [ABSTRACT FROM AUTHOR]

In the fast-changing technological landscape, novel applications are emerging with the potential to reshape the world. These applications, while promising, impose stringent requirements in terms of quality of service (QoS). The advent of wireless networks like 5G, 6G and Wi-Fi 6 brings about resource management solutions to ensure these requirements while meeting the user expectations within the interconnected environment. Nevertheless, user behaviors are also evolving, highlighting the importance of satisfaction and quality of experience (QoE). Furthermore, changes in user behavior trigger shifts in business models, where the quality of business (QoBiz) takes on a pivotal role. This evolving ecosystem, encompassing QoS, QoE, and QoBiz, demands a comprehensive and adaptable approach that conventional QoS management frameworks fail to perform. This paper introduces an implementation methodology for a global QoS management model named QoXphere. The implementation methodology is grounded in machine learning techniques and addresses the multifaceted aspects of quality of service (QoX) and their interconnections within wireless networks. The objective is to facilitate dynamic resource management that not only elevates user satisfaction but also optimizes provider benefits. Real-world examples illustrate the methodology's applicability in widely deployed networks, complemented by simulated scenarios of modern network environments that further validate the approach. [ABSTRACT FROM AUTHOR]

This paper proposes a microwave rectifier designed for the popular 5G band, featuring impedance dispersion compensation and a cross-type impedance matching network. The rectifier has an ultra-high power conversion efficiency. The compensation network employs two parallel transmission lines to counteract the nonlinear shift of the diode input impedance caused by frequency variation. Additionally, the cross-over impedance matching network enhances matching and minimizes losses. After rigorous theoretical analysis and simulation, the rectifier is fabricated. Experimental results show significant conversion efficiency in the 5G band (across 4–6.5 GHz). At an input power of 12 dBm, the rectifier achieves more than 60% efficiency between 4.8 and 6.4 GHz and more than 70% between 5.2 and 6.2 GHz, with a peak efficiency of 78.1%. Moreover, the rectifier maintains more than 50% efficiency over a wide input power range of 5 to 14 dBm. [ABSTRACT FROM AUTHOR]

The ongoing evolution of network softwarization is particularly evident in mobile networks. The 5G standard defines core network functions as discrete processes, facilitating seamless virtualization. The next crucial step is to enable cloud-based deployments independent of specific hardware and hypervisors. In this work, we propose a testbed designed for cloud-based 5G network deployment. Our primary objective is to create an environment conducive to experimenting with cloud-based 5G core deployments and facilitating future research in this domain. We rigorously verified the deployment's correctness, identified key issues, and developed effective solutions to create a robust environment for emerging applications. Additionally, we introduce an innovative extension to a widely used 5G core network implementation by creating a network function that replicates the functionalities of the Network Exposure Function (NEF). This new component facilitates advanced analytics and AI-based optimization, significantly enhancing cloud-based deployments of virtualized 5G networks. [ABSTRACT FROM AUTHOR]

VANET is a category of MANET that aims to provide wireless communication. It increases the safety of roads and passengers. Millions of people lose their precious lives in accidents yearly, millions are injured, and others incur disability daily. Emergency vehicles need clear roads to reach their destination faster to save lives. Video streaming can be more effective as compared to textual messages and warnings. To address this issue, we proposed a methodology to use visual sensors, cameras, and OBU to record emergency videos. Initially, the frames are detected. After re-recording, the frames detection algorithm detects the specific event from the video frames. Blockchain encrypts an emergency or specific event using hashing algorithms in the second layer of our proposed framework. In the third layer of the proposed methodology, encrypted video is broadcast with the help of 5G wireless technology to the connected nodes in the VANET. The dataset used in this research comprises up to 72 video sequences averaging about 120 seconds per video. All videos have different traffic conditions and vehicles. The ResNet-50 model is used for the feature extraction process of extracted frames. The model is trained using Tensorflow and Keras deep learning models. The Elbow method finds the optimal K number for the K Means model. This data is split into training and testing. 70% is reserved for training the support vector machine (SVM) model and test datasets, while 30%. 98% accuracy is achieved with 98% precision and 99% recall as results for the proposed methodology. [ABSTRACT FROM AUTHOR]

Fabrication of low-RF loss GaN-on-Si high electron mobility transistor stacks is critical to enable competitive front-end-modules for 5G and 6G applications. The main contribution to RF losses is the interface between the III-N layer and the HR Si wafer, more specifically the AlN/Si interface. At this interface, a parasitic surface conduction layer exists in Si, which decreases the substrate effective resistivity sensed by overlying circuitry below the nominal Si resistivity. However, a clear understanding of this interface with control of the parasitic channel is lacking. In this Letter, a detailed physical and electrical description of metalorganic chemical vapor deposition-grown AlN/Si structures is presented. The presence of a SiCxNy interfacial layer is revealed, and its importance for RF losses is shown. Through C–V and I–V characterization, an increase in the C concentration of this interfacial layer is linked to the formation of negative charge at the AlN/Si interface, which counteracts the positive charge present in the 0-predose limit. The variation of the TMAl predose is shown to allow precise tuning of the C composition and, consequently, the resulting interface charge. Notably, a linear relationship between the predose and the net interface charge is observed and confirmed by the fabrication of an AlN/Si sample with close to zero net charge. In addition, a higher Dit (∼ 2 × 10 12 c m − 2 ) for such compensated samples is observed and can contribute to low-RF loss. An exceptionally high effective resistivity of above 8 kΩ cm is achieved, corresponding to an RF loss below 0.3 dB/mm at 10 GHz. [ABSTRACT FROM AUTHOR]

This paper describes the design of a multistage decimator for the Physical Random Access Channel (PRACH) receiver based on the hybrid time/frequency domain architecture. Flexible structure of the multistage decimator allows to support all combinations of PRACH subcarrier spacings and carrier bandwidths defined in the 3rd Generation Partnership Project (3GPP) Release 15 for Frequency Range (FR) 1. Impulse responses of low pass filters for each decimation stage do not depend on a selected combination allowing to facilitate hardware implementation. The multistage decimator jointly uses the Cascaded Integrator-Comb (CIC) and Nyquist filters to minimize number of required multipliers. Acceptable degradation level due to decimation in the receiver performance is estimated based on requirements defined by the Radio Access Network (RAN) working group 4. Assuming no specific detection algorithm, it is shown that the proposed design introduces negligible degradation, less than 0.1 dB in the operating Signal-to-Noise Ratio (SNR) region. [ABSTRACT FROM AUTHOR]

In this article, the Integrated M-SIW (Microstrip-Substrate Integrated Waveguide) band-pass filter-patch antenna (IMBPF-PA) design with 5.90 GHz resonant frequency and the out-of-band suppression is presented, produced and measured for 5G applications using the CST (Computer Simulation Technology) Studio Suite program. The out-ofband frequencies in the 1.50-12.00 GHz wide operating frequency region are suppressed in the BPIGF-PA design. The antenna gain increase in the simulation results of the filter-antenna compared to the patch antenna is 0.32% and the in-band frequency range increase is 22%. In the measurement, the antenna gain increase was 0.78% and the in-band frequency range increase was 14.4%. [ABSTRACT FROM AUTHOR]

A new structure of distributed Doherty low-noise amplifier is implemented on a GaAs pHEMT substrate, using the ED02AH process design kit tailored for 5G applications. This circuit exhibits high linear gain and a consistent noise factor across the frequency range of 22 to 42 GHz. The LNA comprises 10 cells distributed across two stages, with a performance adjustment circuit added to the source electrode of each transistor. Operating with a VGS = –0.15 V and VDS = 1.8 V bias, the LNA delivers an S21 gain of 22.5 ± 2.5 dB and noise figure of 3 ± 0.55 dB, consuming 980 mW of power. The linear performance of the LNA is affirmed by an input 1 dB compression point (IP1dB) of 11 dBm and a third-order input intercept point (IIP3) of 13 dBm. With a surface area of 2.9 × 1.2 mm2, the LNA has a figure of merit of 73.14, demonstrating the high efficiency of the proposed Doherty distributed structure. [ABSTRACT FROM AUTHOR]

Abstract—Today, drones need a reliable data network to perform operations such as command and control or autonomous flight. Combined with hybrid architecture of cellular and satellite networks, drones can fly quickly and safely in urban areas. A large number of connected objects can only develop if it is possible to make them entirely energy autonomous. In this article, we describe an optimal and environmentally friendly solution to these problems; it is renewable energy harvesting technology (solar, electromagnetic) that can extend the life of these sensors. This vision has given rise to a conversion system that we have called "Solar Rectenna." Our contribution allows the energy autonomy of a drone, thus ensuring a combination of cellular and satellite networks allowing commercial drones to fly quickly and safely in urban areas. A 5G antenna at 60 GHz has been proposed and studied and the simulation results of this one is very advantageous with a gain of 6 dBi, a bandwidth of approximately 4 GHz and a reflection parameter S11 at –25 dB. An identical two-antenna MIMO system based on the 60 GHz antenna has been developed whose purpose of increasing the number of transmitting and receiving antennas to improve the communication quality and increase the channel capacity. Good results of S-parameter simulations |S11| and |S21| are obtained with an isolation method between the two antennas based on SRR metamaterials. Finally, the antenna array will be included on the back side of our solar cell to design our solar rectenna system which will be dedicated to the recovery of energy for the supply of drones and the transmission of their data via satellite in rural and urban areas, such as the detection of forest fires via drones equipped with thermal cameras. [ABSTRACT FROM AUTHOR]

In this article, a low loss and compact microstrip ultra-wideband bandpass filter (UWB-BPF) with a narrow-notched band is recommended for suitable applications in ultra-wideband wireless communication systems. The design methodology is presented to develop the microstrip structure of the UWB-BPF pursued by a single notched band (NB) in the passband of the UWB filter. An array of I-shaped defected ground structures and L-shaped defected microstrip structures based lowpass filters is cascaded with a shorted stub based highpass filter to achieve a UWB-BPF response. The two identically folded open stubs are loaded to obtain the narrow NB. The center frequency of the UWB-BPF without the NB is 3.5 GHz, and the stopband is suppressed up to 14.5 GHz. The fractional bandwidth achieved is 160%, with a circuit area of 0.11 ${\rm{\lambda }}_{\rm{g}}^{\rm{2}}$ λ g 2 . Furthermore, the single NB is attained at 5.7 GHz to reject interferences of signal from the 5G network with an attenuation level of 59 dB. The electromagnetic simulated and experimental responses of the designed structures demonstrate a well-matched behavior among them. The NB at 5.7 GHz in the UWB-BPF passband region suppresses the signal interference from the 5G network (5500 MHz), WLAN (5900 MHz), and WiMAX (5800 MHz). [ABSTRACT FROM AUTHOR]

An array antenna for millimeter-wave communication and an array antenna for millimeter-wave sensing are designed and put together into one structure. Because millimeter-wave signals become weaker fast with the increasing distance and any kind of error in the required functions of the antenna has to be minimized, pointing error from the target direction should be prevented. The device is a millimeter-wave sensing antenna with high directivity to check the straight link between the TX and RX sides of wireless communication. A 24 GHz 8-by-16 array antenna which generates stronger signals for sensing resolves the drawback of a 28 GHz 1-by-4 array antenna that is commonly seen in 5G wireless terminals. The sensing and communication antennas are integrated as a planar structure mountable on platforms, which is investigated with regard to forming wireless links over a distance of several meters with an input power of less than 0 dBm. Additionally, in the event of a reflecting surface disturbing the straight path and worsening the pointing error in RF signal transfer, the dual-capability of the combination is presented on the basis of intuitive electromagnetic experiments. [ABSTRACT FROM AUTHOR]

The paper addresses the investigations of four elements MIMO antenna with reconfigurable grounds for 5 G NR n3/n1/n40/n41/n77/n79 to X-bands using PIN diodes. Initially, a single unit ultra wideband antenna is implemented, and then it is extended to 2 × 2 MIMO with reconfigurable grounds using one PIN diode. Later, the 4 × 4 MIMO antenna with reconfigurable grounds using six PIN diodes is developed. This study has the novelty that it gives the analysis and design of MIMO antennas switching between unconnected and connected grounds by the method of reconfiguration. The proposed 4 × 4 MIMO is fabricated on FR4 substrate with a volume of 0.485λ0 × 0.326λ0 × 0.0075λ0 mm3, where λ0 is calculated at a lowest resonating frequency. It has operating frequency bands of 1.4–1.6 GHz, 1.75–2.5 GHz and 2.7–13 GHz with connected grounds. The port isolation in the majority of the band is ≤ −15 dB. The inference is included on all the performance metrics. The fabricated MIMO performance is in line with simulated results and hence validates the observations of this research work. So, the proposed MIMO designs are compatible with 5 G wireless applications. [ABSTRACT FROM AUTHOR]

This paper presents a novel design method for a tri‐band multiple in multiple out (MIMO) antenna. The antenna consists of four sets of identical antenna pairs arranged on the two side frames. Three resonant modes can be obtained using a microstrip coupling feed structure by employing different branches in antenna unit design. The working frequencies of the modes can be adjusted independently. Moreover, in each pair of antennas, two antenna units were closely arranged and a decoupling grounding branch was employed between the adjacent antennas to ensure good isolation. The tri‐band eight‐element MIMO antenna operates at 3.5, 4.9, and 5.6 GHz and the isolations were better than 14 dB. The proposed antenna had a low profile of 0.06λ0 ${\lambda }_{0}$ and good isolation so it has potential applications in 5G mobile terminals. [ABSTRACT FROM AUTHOR]

The 5th generation (5G) and beyond use Internet of Things (IoT) to offer the feature of remote monitoring for different applications such as transportation, healthcare, and energy. There are several advantages of 5G and beyond for IoT applications like high speed and low latency. However, they are prone to cybersecurity threats due to networks softwarization and virtualization, thus raising additional security challenges and complexities. In this paper, we conducted a systematic literature review (SLR) of cybersecurity for 5G and beyond-enabled IoT. By developing a taxonomy to classify and characterize existing research, we identified and analyzed strategies, key patterns, mechanisms, performance evaluation, validation parameters and challenges of cybersecurity and resilience for 5G and beyond-enabled IoT in existing studies. We used "Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)" recommendations for this SLR. Through our search in scientific databases, 4449 records published between 2017 and 2023 were initially identified, which were then reduced to 558 records after title and abstract screening to be considered for the eligibility check process. After screening the full-text, 79 articles were finalized for thorough analysis. The findings of this study suggest that 35% of the included studies focus on authentication and access control as security aspects, 59% studies are based on combination of both network layer and application layer as main operation layer, and 34% of the included studies use real-time implementation for validation purpose while the remaining studies utilize simulation or theoretical analysis. Our SLR also highlights open research challenges of 5G and beyond-enabled IoT cybersecurity and suggests a tentative solution for each challenge, which can be a focus of future research. Finally, key limitations of our SLR and threats to validity are addressed. [ABSTRACT FROM AUTHOR]

Summary: Voice services have progressed significantly since the launch of mobile phones and have evolved from analog technology to digital ones. Since the launch of 5G, voice over 5G (Vo5G) will slowly take over legacy mobile technologies to provide better voice services. Nevertheless, interruptions and noise will continue to affect speech communication over wireless networks, ensuing in a reduced Quality of Service (QoS). Three enhanced transmission schemes for Vo5G are proposed. The first proposal benefits from the difference in weight of the bits of internet Low Bitrate Code (iLBC) coded packets to offer them diverse degrees of protection i.e. Unequal Error Protection (UEP). UEP enhances the reception quality by allowing the more significant bits to be decoded with greater reliability during 5G transmission. The second and third schemes substitute the usual Quadrature Amplitude Modulation (QAM) constellation with a Statistical QAM (SQAM) one. The second scheme arranges the significant bits on the SQAM constellation and the remaining bits onto the conventional QAM arrangement. For the third scheme, all the bits are arranged on the SQAM constellation. Generative Adversarial Networks (GAN) were incorporated into the third scheme as the third scheme provided better gains over the first and second schemes. GAN was used to synthesize and enhance parts of the speech file that were lost during transmission over the 5G channel resulting in a gain in Segmented Signal to Noise Ratio (SSNR). The addition of GAN boosted the gain obtained by the third scheme by 1.45 dB with 16‐QAM at a code rate of 1/3. [ABSTRACT FROM AUTHOR]

Summary: A 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. [ABSTRACT FROM AUTHOR]

In vehicular communications, channel estimation is a complex problem due to the joint time–frequency selectivity of wireless propagation channels. To this end, several signal processing techniques as well as approaches based on neural networks have been proposed to address this issue. Due to the highly dynamic and random nature of vehicular communication environments, precise characterization of temporal correlation across a received data sequence can enable more accurate channel estimation. This paper proposes a new pilot constellation scheme in combination with a small feed‐forward neural network to improve the accuracy of channel estimation in V2X systems while keeping low the implementation complexity. The performance is evaluated in typical vehicular channels using simulated BER curves, and it is found superior to traditional channel estimation methods and state‐of‐the‐art neural‐network‐based implementations such as feed‐forward and super‐resolution. It is illustrated that the improvement becomes pronounced for small subcarrier spacings (or low 5G numerologies); hence, this paper contributes to the development of more reliable mobile services across rapidly varying vehicular communication channels with rich multi‐path interference. [ABSTRACT FROM AUTHOR]

Within the evolving landscape of fifth‐generation (5G) wireless networks, the introduction of network‐slicing protocols has become pivotal, enabling the accommodation of diverse application needs while fortifying defences against potential security breaches. This study endeavours to construct a comprehensive network‐slicing model integrated with an attack detection system within the 5G framework. Leveraging software‐defined networking (SDN) along with deep learning techniques, this approach seeks to fortify security measures while optimizing network performance. This undertaking introduces network slicing predicated on SDN with the OpenFlow protocol and Ryu control technology, complemented by a neural network model for attack detection using deep learning methodologies. Additionally, the proposed convolutional neural networks‐long short‐term memory approach demonstrates superiority over conventional ML algorithms, signifying its potential for real‐time attack detection. Evaluation of the proposed system using a 5G dataset showcases an impressive accuracy of 99%, surpassing previous studies, and affirming the efficacy of the approach. Moreover, network slicing significantly enhances quality of service by segmenting services based on bandwidth. Future research will concentrate on real‐world implementation, encompassing diverse dataset evaluations, and assessing the model's adaptability across varied scenarios. [ABSTRACT FROM AUTHOR]

This paper presents a proposal to improve the software implementation of SNOW-V, a candidate for encrypting 5G communications. In particular, we focus on the proposal for 32-bit architectures with limited resources, such as wireless sensor networks. SNOW-V is a pseudorandom number generator, this type of structures are traditionally implemented in hardware. The advent of 5G means that this implementation must be purely software, losing the advantages and speed of a purely hardware or even hybrid implementation. Due to the wide variety of interconnected devices in the IoT, we cannot assume or associate security with a given architecture or unlimited resource devices. For this reason, we have focused our efforts on analyzing and improving the speed of the proposed 5G encryption on lightweight architectures. Specifically, we analyze its software implementation and propose improvements to speed up the encryption process while protecting confidentiality and integrity for 32-bit devices. [ABSTRACT FROM AUTHOR]

We propose a geographical location and trust-based framework combined with community detection algorithms to filter communities of malicious users in 5G social networks. This framework utilizes geo-location information, community trust within the network and AI community detection algorithms to identify users that can cause harm. It has a benefit over some other fake user detection mechanisms because it takes into account the characteristics that a malicious user cannot easily fake like the geographical location and community trust built throughout time. We illustrate the proposed framework on synthetic social network data. Results show this framework can distinguish potential malicious users from trustworthy users based on their location, trust, and structural attributes. [ABSTRACT FROM AUTHOR]

5G New networking applications need the development of mobile data networks. The edge networks enabled by 5G technology will be able to collect, analyze, and act on more data, enabling the emergence of an intelligent internet that connects everything. To satisfy the needs of this new paradigm, access points and network nodes need to be outfitted with high-performance networking, processing power, and storage. Modern coding and encryption technology are required for 5G's success because of the importance of security and dependability in expanding communication. Chaos sequence complexity simulations using polarization nodes and chaotic classifications are used in this research to improve transmission efficiency and congeniality. Codes and chaotic sequences are intertwined in the polarization pieces preserved in time. Errors in both the set and encoded forms might occur simultaneously. Decrypting the bits without chaotic patterns is easier for eavesdroppers don't have access to the frozen pieces. Chaotic sequences may be generated using chain state information for added security. Decryption complexity is increased because of the chain effects of late feedback for eavesdroppers. Conceptual analyses and simulation findings demonstrate the proposed improved chaotic sequence complexity algorithm explores high levels of security and reliability without an error rate. The proposed algorithm increases in Key Space, Sensitivity, and data entropy by 46.21%, 50.25%, and 46.45% respectively. [ABSTRACT FROM AUTHOR]

C-RAN (Cloud Radio Access Network) is a 5G architecture that consists of sites and three-layer Data Centers (DCs), which include the central office DC, local DC, and regional DC. Network slicing, which enables infrastructure providers (InP) to create independent logical networks, is essential in this architecture. By utilizing this technology, InPs can maximize the utility of the network by providing slices to service providers in response to their slice requests. However, almost all of the recent research on slice admission control (SAC) schemes has only considered one or two layers of DCs, which limits the efficiency of the slicing process and decreases network utility. To address these issues, this paper proposes an intelligent SAC scheme called ISAC that considers all three-layer DCs. Instead of relying on reinforcement learning algorithms like Q-learning, which are effective in discrete environments with limited state space but give poor performance in continuous environments, ISAC employs the Approximate Reinforcement Learning (ARL) algorithm. ARL is better suited for 5G network modeling because it can adapt to continuous environments, allowing for a more accurate representation of the underlying physical processes. Extensive simulation studies demonstrate that ISAC significantly improves performance in terms of slice request rejection rates, InP revenue, accepting more slices, and optimizing resource utilization. [ABSTRACT FROM AUTHOR]

The growing need for applications with low latency and high bandwidth in 5G networks has shifted the emphasis towards integrating edge computing into mobile network architectures. The optimal deployment of edge servers (ESs) is crucial for balancing performance and cost. Current research primarily focuses on the optimal deployment of ESs. However, there is limited attention on forecasting the workload of ESs, particularly in scenarios where they are placed in their optimal positions, which is crucial for accommodating anticipated variations in user densities and workload fluctuations expected in the near future. This research forecasting of workload in 5G networks by leveraging the Temporal Hierarchical Attention Mechanism Network (THAMNET) model for accurate Internet traffic forecasting. Addressing this gap, the Max–Min Fairness Allocation Scheme (MMF-AS) algorithm is implemented to ensure a balanced workload distribution. This approach facilitates fair allocation of Base Stations (BSs) to ESs, taking into account factors such as workload, distance, and connectivity. A novel approach is introduced by integrating the THAMNET forecasting model with the Particle Swarm Optimization (PSO) and MMF-AS algorithms. The proposed method considers predicted future traffic demands, and connectivity between ESs and BSs, and aims to achieve balanced workload distribution, higher utilisation rates, minimised latency, and reduced energy consumption. Experimental results demonstrate equitable workload distribution 25.95%, utilisation rate 17.57%, and notable reductions in latency 47.61% and energy consumption 32.28% compared to the non-forecasting comparison. [ABSTRACT FROM AUTHOR]

In this research, we explain comprehensive industrial and innovation results on using an artificial neural network (ANN) method to improve the performance of microstrip patch antennas for 5G, indoor-outdoor, and Ku band uses. To determine if an antenna is appropriate, this article discusses multiple methods, one of which is to do a simulation using validating software like high frequency structure simulator (HFSS) and Altair Feko. Based on the Rogers RT 5880 substrate, the antenna is constructed. There is a loss tangent of 0.0009 and its dimensions are 17.1053 mm in length and 16 mm in width. Its dielectric constant is 2.2. Despite its small size, it boasts an impressive maximum efficiency of almost 90% and a gain of approximately 8 dB. As an indicator of ANN model performance, we may look at the R-squared value (99%), the mean square error (MSE), which is approximately 0.0015, and the confidence interval (99%). The ANN models are the most accurate and have the lowest error rate when it comes to predicting efficiency and gain. The suggested antenna is a promising contender for the targeted Ku band, indoor/outdoor, and 5G uses, as verified by the clustering of computer simulation technology (CST), HFSS, and Altair Feko simulated results with the measured and predicted outcomes of ANN approach. [ABSTRACT FROM AUTHOR]

The emergence of 5G represents a pivotal step in merging mobile communication networks with the Industrial Internet of Things. Despite the numerous advantages of 5G, the presence of unknown obstacles can adversely affect user signals. Although mitigating signal pressures can be achieved by increasing base station density, it often involves bulky equipment and high costs. To address this, we propose a deep learning-based method for controlling tunable transmissive metasurfaces and validate their scattering control capabilities in the presence of obstacles. By constructing a network model to analyze the mapping relationship between metasurface arrays and far-field scattering, rapid control of scattering characteristics is achieved. AI-driven high-performance tunable metasurfaces exhibit vast potential applications in intelligent communication, offering a universal solution for intelligent control in complex signal environments. [ABSTRACT FROM AUTHOR]

A 28/38 GHz quad-port cross-shaped antenna printed on a 0.203 mm Roger RO4003 substrate is designed and fabricated for 5G networks. The antenna consists of a rectangular patch radiator with three triangle slots to enhance the antenna's impedance matching. The four elements are arranged in a cross-shaped layout to achieve the desired compactness of 29 mm × 24.2 mm × 0.203 mm. A thin parasitic strip is inserted between the second and fourth elements to enhance the port isolation. The designed antenna is simulated by utilizing the CST simulator. The antenna achieved S11 < -10 dB at 28 / 38 GHz, with isolation ≥ 20 dB. Furthermore, the E- and H-planes within the anechoic chamber are evaluated to validate the MIMO antenna radiation patterns and gain. The MIMO parameters are calculated, simulated, tested, and its outcomes are under the standard level which confirms the MIMO diversity feature. The ECC of the structure is < 0.001, the DG ≥ 9.95 dB. and the CCL was ≤ 0.2 bit/s/Hz across the dual working band. [ABSTRACT FROM AUTHOR]

Dual beam scanning (DBS) antenna exited by two different spoof surface plasmon polaritons (SSPPs) transmission lines is proposed in this paper. The antenna is constructed by placing three rows of circular patches on both sides of two different planar SSPPs waveguide. These patches convert the SSPP guided waves into radiating waves. This simple single-layer antenna is characterized by dual without need to use switches or other complex configurations. It is designed to support application of several 5G sub-6 GHz bands (3.5 (n78) GHz, 3.7 (n77) GHz, and 4.5 (n79) GHz). The proposed antenna realizes the dual beam scanning by controlling the dispersion properties and field confinement along two different SSPPs transmission lines, based on different propagation constant. Numerical simulations are carried out by CST Microwave Studio and Ansys HFSS. These numerical simulations are verified by experimental results over the operating frequency band from 1 GHz to 6 GHz. [ABSTRACT FROM AUTHOR]

Cross-region innovation is widely recognized as an important source of the long-term regional innovation capacity. In the recent past, a growing number of studies has investigated the network structure and mechanisms of cross-region innovation collaboration in various contexts. However, existing research mainly focuses on physical effects, such as geographical distance and high-speed railway connections. These studies ignore the intangible drivers in a changing environment, the more digitalized economy and the increasingly solidified innovation network structure. Thus, the focus of this study is on estimating determinants of innovation networks, especially on intangible drivers, which have been largely neglected so far. Using city-level data of Chinese patents (excluding Hong Kong, Macao, and Taiwan Province of China), we trace innovation networks across Chinese cities over a long period of time. By integrating a measure on Information and Communications Technology (ICT) development gap and network structural effects into the general proximity framework, this paper explores the changing mechanisms of Chinese innovation networks from a new perspective. The results show that the structure of cross-region innovation networks has changed in China. As mechanisms behind this development, the results confirm the increasingly important role of intangible drivers in Chinese inter-city innovation collaboration when controlling for effects of physical proximity, such as geographical distance. Since digitalization and coordinated development are the mainstream trends in China and other developing countries, these countries' inter-city innovation collaboration patterns will witness dramatic changes under the influence of intangible drivers. [ABSTRACT FROM AUTHOR]

With the continuous advancement of virtualization technology and the widespread adoption of 5G networks, the application of the Network Function Virtualization (NFV) architecture has become increasingly popular and prevalent. While the NFV architecture brings a lot of advantages, it also introduces security challenges, including the effective and efficient verification of the integrity of deployed Virtual Network Functions (VNFs) and ensuring the secure operation of VNFs. To address the challenge of efficiently conducting virtual remote attestation for VNFs and establishing trust in virtualized environments like NFV architecture, we propose TVRAVNF, which is a highly efficient and low-cost TEE-based virtual remote attestation scheme for VNFs. The scheme we proposed ensures the security and effectiveness of the virtual remote attestation process by leveraging TEE. Furthermore, we introduces a novel local attestation mechanism, which not only reduces the overall overhead of the virtual remote attestation process but also shortens the attestation interval to mitigate Time-Of-Check-Time-Of-Use attacks, thereby enhancing overall security. We conduct experiments to validate the overhead of the TVRAVNF scheme and compare its performance with that of a typical remote attestation process within a maximum unattested time interval. The experimental results demonstrate that, by employing the local attestation mechanism, our solution achieves nearly an 80% significant performance improvement with a relatively small time overhead for small to medium-sized files. This further substantiates the significant advantages of our approach in both security and efficiency. [ABSTRACT FROM AUTHOR]

With the exponential growth in data density and user ends of wireless networks, fronthaul is tasked with supporting aggregate bandwidths exceeding thousands of gigahertz while accommodating high-order modulation formats. However, it must address the bandwidth and noise limitations imposed by optical links and devices in a cost-efficient manner. Here we demonstrate a high-fidelity fronthaul system enabled by self-homodyne digital-analog radio-over-fiber superchannels, using a broadband electro-optic comb and uncoupled multicore fiber. This self-homodyne superchannel architecture not only offers capacity boosting but also supports carrier-recovery-free reception. Our approach achieves a record-breaking 15,000 GHz aggregated wireless bandwidth, corresponding to a 0.879 Pb/s common public radio interface (CPRI) equivalent data rate. Higher-order formats up to 1,048,576 quadrature-amplitude-modulated (QAM) are showcased at a 100 Tb/s class data rate. Furthermore, we employ a packaged on-chip electro-optic comb as the sole optical source to reduce the cost, supporting a data rate of 100.5 Tb/s with the 1024-QAM format. These demonstrations propel fronthaul into the era of Pb/s-level capacity and exhibit the promising potential of integrated-photonics implementation, pushing the boundaries to new heights in terms of capacity, fidelity, and cost. Here the authors propose a self-homodyne fronthaul architecture, utilizing DA-RoF super channels and multicore fiber, paving the way for the Pb/s era in fronthaul transmission, enabling ultra-highspeed Internet access. The remarkable data speeds reaching 0.879 Pb/s and the 256-QAM format make it possible for 150,000 5G channels to be accessed simultaneously. [ABSTRACT FROM AUTHOR]

This paper proposed a two port antipodal vivaldi antenna (AVA) for 5G FR2 (frequency range 2) applications at 28 GHz with improved bandwidth,gain and isolation. Each antenna consists of two array elements. The proposed antenna has dimensions 23.8 × 54 × 0.79 mm3 and is fabricated on Rogers RT/Duroid 5880 material. This material has a 2.2 low dielectric constant and mainly suitable for broadband high frequency applications. Proposed antenna covers −10 dB below from 25.51 to 33 GHz band, which having 7.49 GHz bandwidth. Gain for the presented MIMO (Multiple input multiple output) AVA array is varying from 8.50 to 12.44 dBi. A better isolation −34.56 dB is obtained between two antenna elements. MIMO characteristics like ECC (Envelope correlation coefficient), CCL (Channel capacity loss), DG (Diversity Gain), TARC (Total active reflection coefficient), and MEG (Mean effective gain) are satisfied with good results for presented antenna. The proposed antenna is designed using ansys HFSS simulation tool. [ABSTRACT FROM AUTHOR]

This paper presents method for integrating two dual port multiple input multiple output (MIMO) antennas on a common substrate based on substrate integrated waveguide (SIW) technology. One of the dual port MIMO antennas (MIMO_1) resonates at 31.2 GHz with an impedance bandwidth of 1 GHz while the other dual port MIMO antenna (MIMO_2) exhibits an impedance bandwidth of 925 MHz and resonates at 36 GHz. The radiators etched on the SIW cavities are complementary slotted annular rings (CSAR). Isolation between the ports is more than 20 dB which is inherently achieved by SIW cavity backed structures. The MIMO antenna realized at 31.2 GHz exhibit a peak realized gain of 8.5 dBi while the MIMO antenna realized at 36 GHz displays a peak gain of 9.8 dBi. The diversity gain of both the MIMO antennas is around 9.9 dB and the envelope correlation coefficient (ECC) of the MIMO antenna realized at 31 GHz is below 0.004 while the ECC of MIMO antenna at 36 GHz is below 0.006. It is also confirmed that simulated results closely correlate with the measurement results. [ABSTRACT FROM AUTHOR]

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The immense growth of mobile networks leads to versatile applications and new demands. The improved concert, transferability, flexibility, and performance of innovative network services are applied in diversified fields. More unique networking concepts are incorporated into state-of-the-art mobile technologies to expand these dynamic features further. This paper presents a novel system architecture of slicing and pairing networks with intra-layer and inter-layer functionalities in 5th generation (5G) mobile networks. The radio access network layer slices and the core network layer slices are paired up using the network slicing pairing functionalities. The physical network elements of such network slices will be logically assigned entities called softwarization of the network. Such a novel system architecture called network sliced softwarization of 5G mobile networks (NSS-5G) has shown better performances in terms of end-to-end delay, total throughput, and resource utilization when compared to traditional mobile networks. Thus, effective resource management is achieved using NSS-5G. This study will pave the way for future softwarization of heterogeneous mobile applications. [ABSTRACT FROM AUTHOR]

This article presents three efficient rectifiers for radio frequency energy harvesting (RFEH) systems operating at the fifth generation (5G) band (3.5 GHz). Each rectifier operates at various input power levels (high, low, and across a wide power range). The high and low-power rectifiers feature a single serial topology using HSMS-2860 and SMS-7630 Schottky diodes, respectively, along with microstrip lines to implement the input and output filters and the impedance matching network. At an radio frequency (RF) power level of 15 dBm, the high-power rectifier harvests 67.4% to direct current (DC) power with a 300 Ω load resistor and an output voltage of 2.5 V. The low-power rectifier achieves its maximum power conversion efficiency (PCE) at -2 dBm, reaching 45% efficiency with a 1,200 Ω load. The rectifier with a extended input power range comprises two branches of subrectifiers functioning at both high and low power levels. Depending on the power level, the considered subrectifier harvests radio frequency power into DC power, while the other subrectifier is deactivated. Across a power span of 32.5 dB (ranging from -13 to 19.5 dBm), the rectifier maintains an efficiency above 30%. The proposed rectifiers are efficient and suitable for implementation in 5G-enabled RFEH systems. [ABSTRACT FROM AUTHOR]

This paper proposes a broadband eight-antenna array design suitable for Fifth Generation New Radio (5G NR) smartphone applications. To cover the 5G NR bands n77/n78/n79 (3300–5000 MHz) and 5G NR-U n46 band (5150–5925 MHz), the single antenna array unit applied is a modified loop antenna element (MLAE) that can generate three different loop modes. To yield good multi-input multi-output (MIMO) performances, the designed MLAE is further arranged as an eight-antenna array, and the experimental results show that the overlapping 6 dB bandwidth can cover the bands-of-interest (3300–5925 MHz) with good isolation and total efficiency of >10 dB and 51–84%, respectively. Finally, good MIMO performances, such as an envelope correlation coefficient (ECC) of lower than 0.1 and desirable channel capacity (CC) of 37–40 bps/Hz, were calculated across the bands-of-interest. [ABSTRACT FROM AUTHOR]

This paper introduces a 12-element asymmetric mirror-coupled loop antenna for integration into 5G smartphones. The proposed antenna includes six identical asymmetrically mirrored (AM)-coupled building blocks, each consisting of two gap-coupled loop antennas, with each building block dimensioning a mere 12 × 7 mm2. The unique architecture of the proposed antenna yields an isolation performance exceeding 14 dB without the necessity for ancillary decoupling elements and effectively covers the dual-band 5G mobile frequency bands of 3.3-3.6 GHz and 4.8-5.0 GHz. The antenna was optimized using simulation software HFSS, and the results indicate an antenna's envelope correlation coefficient of less than 0.016 and an efficiency range of 72%-81%. Finally, the performance of single-hand and double-hand handset smartphone modes is discussed, which still exhibit good radiation and MIMO performance under both modes, demonstrating their stability in practical applications. Simulation and measurement results indicate that the proposed 12-element MIMO antenna holds great promise for 5G smartphone applications. [ABSTRACT FROM AUTHOR]

In this paper, a diamond-shaped broadband high-gain microstrip patch antenna based on a folded floor structure is proposed. The overall dimensions of the antenna are 108 mm×100 mm×25 mm. Additionally, it contains a radiating microstrip patch, a folded ground plane, and a capacitive feed strip. The broadening of the antenna's operating band is achieved by enhancing the microstrip radiating patch and capacitive feed band. The original rectangular structure was transformed into a rhombic structure, enabling the radiating patch to absorb the current more effectively and achieve a better impedance match for the antenna operating around 5 GHz. The radiation performance of the antenna is maximized by utilizing the folded floor structure. Measured results show that the impedance bandwidth of the antenna is about 61.5% (2.84 GHz-5.36 GHz), covering 5G dual bands. Meanwhile, the peak gain reaches 12.6 dBi, and the average gain reaches 10.7 dBi. [ABSTRACT FROM AUTHOR]

The rapid expansion of wireless communication systems has spurred a growing demand for adaptable multiple-input multipleoutput (MIMO) antennas capable of accommodating diverse frequency bands and operational environments. This paper presents a compact quad-port wide-band tuning-reconfigurable MIMO antenna tailored specifically for 5G applications operating within the sub-6 GHz spectrum. The proposed design enhances isolation levels (> 18 dB) and augments pattern diversity by utilizing four orthogonal radiating elements. Integrating a C-shaped monopole element with a matching stub facilitates frequency tuning via a varactor diode, ensuring a consistent radiation pattern. The lower and upper resonant bands could be fine-tuned by adjusting the varactor diode's reversebiased voltage within the allowed range of 0.5 to 10 V. These bands are 4 to 5.18 GHz and 5.45 to 6.65 GHz, respectively. The proposed antenna system's four C-shaped elements are placed on a 40 × 40 mm2 ground plane and mounted on a Rogers RT5880 substrate that is 0.8 mm thick with a relative permittivity of 2.2. This design is well suited for various wireless applications and cognitive radio networks due to its compatibility with sub-6 GHz frequency bands and wide-band tuning capabilities. [ABSTRACT FROM AUTHOR]