Material Properties Extraction of Mango (Mangifera indica) Leaves at Ka-Band Using a Waveguide Measurement System

The imminent 5G and 6G communication systems are projected to exhibit substantial advancements in comparison to the current 4G communication system. Several critical and prevalent concerns pertaining to the service quality of 5G and 6G communication systems encompass elevated capacity, extensive connectivity, minimal latency, robust security measures, energy efficiency, superior quality of user experience, and dependable connectivity. Undoubtedly, 6G communication is expected to offer markedly improved performance across these domains compared to 5G communication. The integration of the Internet of Things (IoT) within the framework of the tactile internet is anticipated to be a fundamental component of advanced communication systems, encompassing both 5G and beyond (5GB), such as 5G and 6G. Consequently, 5GB wireless networks will encounter various challenges in accommodating diverse types of heterogeneous traffic and meeting the specified parameters related to service quality. Optical wireless communication (OWC), alongside various other wireless technologies, emerges as a promising candidate to fulfill the requisites of 5G communication systems. This comprehensive review articulates the efficacy of OWC technologies, including Visible Light Communication (VLC), Light Fidelity (LiFi), Optical Camera Communication (OCC), and Free Space Optics (FSO) Communication, as a viable solution for the successful deployment of 5G/6G and IoT systems.

ObjectiveThe challenges of an aging population worldwide are the increased number ofpeople needing medical and nursing care and inadequate medical resources.Information and communication technologies have progressed remarkably,leading to innovations in various areas. 5G communication systems arecapable of high-capacity, high-speed communication with low latency and areexpected to transform medicine. We aimed to report a demonstrationexperiment of telerehabilitation and telemedicine using a mobile ultrasoundsystem in a depopulated area in a mountainous terrain, where 32% of thepopulation are 65 years or older.MethodsAt the core hospital, a physician or physical therapist remotely performedultrasonography or rehabilitation on a subject in a clinic. Five generalresidents participated in the telerehabilitation as subjects. The delay timeand video quality transmitted with 5G and long-term evolution (LTE)communication systems were compared. The physician or physical therapistsubjectively evaluated the quality and delay of the transmitted images andsubject acceptability.ResultsOf seven physical therapists, six and three responded that the video qualitywas “good” for telerehabilitation with 5G/4K resolution and LTE,respectively. Five physical therapists and one physical therapist reportedthat the delay time was “acceptable” with 5G/4K resolution and LTE,respectively. For telemedicine using a mobile ultrasound system, theresponses for 5G were “the delay was acceptable” and “rather acceptable.” Incontrast, both respondents’ responses for LTE were “not acceptable.”ConclusionsMultiple high-definition images can be transmitted with lower latency intelerehabilitation and telemedicine using mobile ultrasound imaging systemswith a 5G communication system. These differences affected the subjectiveevaluation of the doctors and physical therapists.

Metamaterials exhibit properties in terms of subwavelength operation or phase manipulation, among others, that can be used in a variety of applications in 5G communication systems. The future and current 5G devices demand high efficiency, high data rate, computational capabilities, cost-effectiveness, compact size, and low power consumption. This variation and advancement are possible when the antenna design is revised to operate over wideband, high gain, and multiband and has characteristics of compact size, reconfiguration, absorption, and simple ease of fabrication. The materials loaded with antennas or, in the same cases, without antennas, offer the aforementioned characteristics to bring advancement in order to facilitate users. A number of works on designing metasurfaces capable of improving bandwidth, gain efficiency, and reducing the size and cost of antennas are available in the literature for this purpose. Not only are these applications possible, but the intelligent metasurfaces are also designed to obtain reconfiguration in terms of frequency and polarization. The number of absorbers loaded with metamaterials is also designed to improve the absorption percentage used for radar applications. Thus, in this paper, the general overview of different types of metamaterials and their role in performance enhancement and application in 5G and 6G communication systems is discussed.

This paper describes the electromagnetic wave (EM) attenuation by concrete blocks focusing on the frequency range 1.70 – 1.88 GHz and 3.40 – 3.80 GHz. The attenuation calculation of concrete was made according to ITU recommendation ITU-R P.2040-1 (07/2015) for conducting dielectric. Also, the attenuation calculation was made using simulated values of S 11 and S 21 parameters. These two sets of computationally derived data were compared with each other, and the differences were not significant. The values of EM wave attenuation during propagation through concrete were compared with the values from the available literature and the deviations are also minor. 5G systems use higher frequencies and the tested concrete materials shield the 5G signals better than 4G signals. The results of this research can be used in the building walls with high attenuation for 4G and 5G communication systems.

The fifth-generation (5G) communication systems are expected to be an important connecting infrastructure for information and knowledge exchanges among people, machines, sensors, devices, and even environments. The technical specifications for 5G communication systems are being made to satisfy performance requirements that are defined in ITU-R documents. In addition, the key performance indicators in 5G communication systems include peak and average data rate, mobility, energy efficiency, spectral efficiency, latency, connection density, and so on. These performance metrics need to be evaluated by simulators at different levels. Therefore, simulators play an important role in evaluating the performance of 5G communication systems as well as an individual technique. Most research institutes, universities, and industries have their own simulators, but with different levels of assumption and implementation depth according to technical needs of individual organization, which makes a fair comparison impossible.

Wireless communication are emerging rapidly in our daily life. For an example in mobile communication current trend we are moving from 4G communication towards 5G communication near the year 2020.Near future 5G communication will be operating at short wavelength, it is more to small cell communication. As we know rain impairment is one of the factor need to be consider by link designer especially in tropical region. In this paper, specific rain attenuation been discussed. An analysis and modelling of $\alpha$ and k value which are known as regression coefficient at 5.8 GHz been compared and presented for three different regression coefficient, $\alpha$ and k factor models. ITU-R, Ayayi and Din model are the most popular for specific rain attenuation predictions in tropical regions by researchers. At the end of the analysis, new regression coefficient factor for operating frequency at 5.8 GHz been establish by comparing all the three models for tropical region. It was found new value of regression coefficient, $\alpha$ =0.63, k=0,13 for operating microwave frequency at 5.8 GHz suits well for the tropical region. This study will be useful information for researchers, link operators and network designers for 5G network in future.

The fifth generation (5G) communication has recently attracted much interest. In this paper we present radio channel measurements on campus at 3.5 GHz, which is the candidate frequency band for the 5G communications. The measurement setup is based on software radio units with a bandwidth of 30 MHz, and the measurements were conducted on campus of Beijing Jiaotong University, China. We discuss the power delay profile, path loss, shadowing, and delay spread. It is found that the path loss exponent is up to 6.16 due to high carrier frequency. A lognormal distribution is used to model the shadowing effect, and the standard deviation is 4.21 dB. Furthermore, the root-mean-square delay spread is around 45 ns in the measured campus environments. The results can be applied to the 5G communication system design.

Mango (Mangifera indica L.) is cultivated in tropical and subtropical regions, with all parts of the tree-including leaves-used traditionally to treat diabetes, infections, pain, and other conditions. Mango leaves contain proteins, minerals, vitamins, and phenolic compounds, including mangiferin, quercetin, and kaempferol, whose content varies by cultivar. This study evaluated the functional and bioactive properties of dried mango leaves from five cultivars (Julie, DLO, Nam Dok Mai, Irwin, and Keïtt) to determine their potential for food and nutraceutical applications. Analyses included water- and oil-related parameters, swelling and solubility indices, foaming and emulsifying properties, and antioxidant activity (DPPH, ABTS, and FRAP in hydroalcoholic and water extracts), complemented by FT-IR/ATR spectroscopy. Significant differences between the five analyzed cultivars were observed. Irwin exhibited the highest antioxidant activity (2.65 ± 0.55 mg TE/g DM in DPPH assay), while Nam Dok Mai demonstrated superior foaming capacity (82.69 ± 7.79 mL). Strong correlations (r > 0.9) between reducing sugars and antioxidant capacity suggest cultivar selection based on sugar content could predict antioxidant potential. FT-IR confirmed the presence of polar phenolic and protein compounds. The results demonstrate that mango leaves offer cultivar-dependent functional and antioxidant attributes relevant to food systems. Their targeted valorization may support sustainable industrial applications and circular bioeconomy strategies, particularly in tropical regions where mango cultivation is widespread.

Radio frequency is a valuable resource for wireless communication systems. The high-frequency band from 6 GHz up to 100 GHz, where continuous and broad spectra exist, is promising to meet the high spectrum requirement of fifth generation (5G) mobile communication systems by 2020. To date, many groups from academia and industry have contributed to devising approaches to allocate and utilize frequency resources from 6 GHz to 100 GHz for 5G and future wireless communication systems. In this paper, we present global efforts to allocate potential frequency bands and field trial progress from 6 GHz to 100 GHz for 5G. From a channel perspective, we summarize research progress and challenges, including channel measurement platforms and channel parameter analysis, both of which are important to extract the inherent channel characteristics and use a high-frequency band for 5G and future wireless communication systems.

New high-frequency 5G and satellite communication systems require fully-metallic antennas and electromagnetic components. These components can be implemented with truncated versions of periodic structures. In order to achieve the desired performance of these future devices, it is of crucial importance to have a precise control of the propagation properties, i.e. the frequency dispersion behavior and stop-bands. Here, we demonstrate the potential use of higher symmetries to diminish the frequency dispersion of periodic structures and control the width of stop-bands with a new type of fully-metallic transmission line, which is loaded with holes on a twist-symmetric configuration. Simulated and experimental results confirm the intrinsic link between the propagation characteristics and the symmetries of a periodic structure. Additionally, we provide a definitive explanation of the recently discovered polar glide symmetry and its potential combination with twist symmetries to produce low-dispersive materials and reconfigurable stop-bands. The promising properties of these structures are demonstrated with a fully-metallic reconfigurable filter, which could be used for future high-frequency 5G and satellite communication systems.

This paper presents the design and analysis of the compact patch antenna for 5G and future generation millimetre-wave communication system. The proposed design consists of FR4 substrate length, width, and height of 21.37 x 5 x 1.59 mm3 , besides two rectangular slots incorporated with a dimension of 0.2 x 2.6 mm2 within the patch of 4.22 x 3.46 mm2 , to enhance the resonance frequency more accurate and one more square slot incorporated in to feed line with the dimension of 0.2 x 0.5 mm2 . The obtained return losses of the design is-21.25dB with gain and voltage standing wave ratio (VSWR) of 3.90dBi,1.18 by using a lumped port configuration. For the specific absorption rate (SAR) evaluation considered as a human head model in high-frequency structure simulator (HFSS) software, the obtained values are within the standard limit, the design covers the frequency range of 28GHz, this design may capable of 5G and next-generation wireless communication system application.

The upcoming fifth- and sixth-generation (5G and 6G, respectively) communication systems are expected to deal with enormous advances compared to the existing fourth-generation communication system. The few important and common issues related to the service quality of 5G and 6G communication systems are high capacity, massive connectivity, low latency, high security, low-energy consumption, high quality of experience, and reliable connectivity. Of course, 6G communication will provide several-fold improved performances compared to the 5G communication regarding these issues. The Internet of Things (IoT) based on the tactile internet will also be an essential part of 5G-and-beyond (5GB) (e.g., 5G and 6G) communication systems. Accordingly, 5GB wireless networks will face numerous challenges in supporting the extensive verities of heterogeneous traffic and in satisfying the mentioned service-quality-related parameters. Optical wireless communication (OWC), along with many other wireless technologies, is a promising candidate for serving the demands of 5GB communication systems. This review paper clearly presents how OWC technologies, such as visible light communication, light fidelity, optical camera communication, and free space optics communication, will be an effective solution for successful deployment of 5G/6G and IoT systems.

In order to support the development of the beyond 5G(B5G) and 6G communication industry and system transformation and upgrading, the connotation of the B5G and 6G communication channel digital twin technology is proposed by combining the key links, key scenes, and key objects of the B5G and 6G communication channel simulation. On the above basis, the application model, function framework, technology framework, and standard framework of the digital twin channel are established for B5G and 6G communication. And the application method of communication channel digital twin is discussed in demonstration design, development, and production, test, operation, and maintenance management, which are the traditional life cycle activities of the B5G and 6G communication system. The above research is expected to provide a useful reference for the industrial development and engineering construction of the B5G and 6G system, and promote the application of digital twin technology in the B5G and 6G communication field and industry, and provide technical support for the realization of the B5G and 6G communication channel digitization, intellectualization, servitization, and green sustainability.

Microwave ferroelectric and reconfigurable antennas

Dielectric constant and dissipation factor of six types of dielectrics were measured during irradiation in a Co60 source. Tests were made at seven frequencies ranging from 100 cycles/sec. to 100 kcycles/sec. by use of the Schering bridge technique. Polystyrene and polyethylene exhibited no change in loss properties when γ‐irradiated to doses as high as 7.7 × 107 and 3.5 × 107 r, respectively. Poly(methyl methacrylate) decreased slightly in dielectric constant and was essentially unchanged in dissipation factor after 5.7 × 107. TFE underwent the most drastic changes. At a very low dose (106 r) the dissipation factor had increased three orders of magnitude (at 100 cycles/sec.) and one order of magnitude (at 100 kcycles/sec.). After peaking, the loss factor decreased slowly. After removal of the source, the loss factor decreased more; then increased rapidly upon admission of air. Both this and the original increase in dissipation factor are indicative of a dipole with a long relaxation time, in which oxygen plays a role. FEP Teflon increased somewhat less than TFE, and the peak was not reached until a dose of 3 × 107 r. Very little effect was produced by the admission of air after irradiation. Dielectric constant decreased with radiation dose. The dissipation factor and dielectric constant of Rayolin N decreased with dose, until a plateau was reached. Very little effect was seen after irradiation, even upon the admission of air. The changes which took place during the radiation period were, as in the case of the other materials, greater at the lower frequencies than they were at the higher frequencies.