TELKOMNIKA (Telecommunication Computing Electronics and Control)
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Dual-band MIMO antenna for wideband THz communication in future 6G applications
Get PDFThis paper presents an industrial and innovation dual-band multiple-input multiple-output (MIMO) antenna designed for terahertz (THz) frequencies to enhance future sixth-generation (6G) communication systems. The antenna utilizes a polyimide substrate with a thickness of 12 µm, a dielectric constant of 3.5 and a tangent loss of 0.0027. Both the patch and the ground plane are constructed from copper, ensuring robust performance. The antenna achieves resonance at 5.45 THz with a gain of 14 dB and a bandwidth of 0.7 THz and at 6.34 THz with a gain of 14.44 dB and a bandwidth of 1.77 THz. Additionally, it demonstrates a minor peak at 7.4 THz and a maximum efficiency of 95.87%. The transmission coefficient shows an isolation of -31.01 dB, indicating excellent separation between antenna elements. Key MIMO performance metrics, containing the envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), total active reflection coefficient (TARC), and channel capacity loss (CCL), were analyzed, displaying optimum performance. An analogous circuit was designed and simulated in advanced design system (ADS) to validate these discoveries, creating comparable reflection coefficients to those attained from computer simulation technology (CST) simulations. These findings approve the antenna’s possible for THz-band 6G wireless communication applications
Graphene-based THz antenna with a wide bandwidth for future 6G short-range communication
Get PDFIn this study, we present the design and investigation of a terahertz (THz) frequency antenna optimized for the 2-10 THz range, featuring both single-element and multiple-input multiple-output (MIMO) configurations, with a focus on industrial and innovative applications to enhance future 6G communication systems. The antenna, constructed on a polyimide substrate with dimensions of 90×30 µm, achieves a bandwidth from 4.0328 to 10 THz. The MIMO configuration, which includes two ports, demonstrates excellent isolation with a value of -27 dB. The proposed antenna system achieves a gain of 12.38 dB and an efficiency of 89%, making it highly appropriate for THz communication applications. Furthermore, the envelope correlation coefficient (ECC) of 0.002 and diversity gain (DG) of 9.99 affirm the antenna’s effectiveness in MIMO systems. A resistance inductance capacitance (RLC) circuit model was employed to accurately represent the S11 curve, ensuring precise characterization of the antenna’s performance. These results underscore the probability of the proposed antenna for high-speed, short-range communication systems
Optimization of principal component analysis and k-nearest neighbors in cultivation area classification red onion
Get PDFThis research aims to increase the effectiveness in classifying shallot cultivation areas through the combined application of principal component analysis (PCA) and k-nearest neighbors (KNN) methods. Shallot is an important agricultural commodity, and identification of optimal areas for its cultivation is essential to support food self-sufficiency. Onion cultivation is generally done in the highlands. One of the areas with shallot cultivation in North Sumatra Province is Berastagi, Karo Regency. This research was conducted by determining the spatial extent of upland land. In the use of data there are 2 types of data that will be used: land suitability dataset and land condition dataset for each region. The PCA method is utilized to simplify the data structure by reducing the number of dimensions and removing insignificant attributes, while KNN was used to classify regions based on their suitability for shallot cultivation. This research produces a classification map that can be used to identify the most optimal areas for shallot cultivation. The test results with the regional spatial dataset using precision, recall and fi-score testing accuracy value 0.92%, and macro avg value 0.94%, weighted avg value 0.93%
A compact triband patch antenna design at terahertz frequencies
Get PDFThe rapid evolution of terahertz (THz) technology has fueled an increasing demand for efficient, compact, and adaptable antennas that can function for a number of frequency bands in the THz spectral regime. This research outlines the analyses and design process of a multiband antenna for THz applications. Initially, an antenna with a single frequency band is created without any slot, with its lower resonant mode functions at a singular frequency of 171 GHz. To achieve multiband functionality, various rectangular slots can be added into the microstrip antenna’s radiating element. The suggested structure is constructed on a polyimide substrate, while its radiating elements are crafted from copper, with a compact size of 1.4×1.1×0.14 mm. It can achieve a reflection coefficient of −30.38 dB, −33.37 dB, and −19.33 dB at 123 GHz, 168 GHz, and 182 GHz, respectively. Furthermore, the antenna yields favorable gains at the respective frequencies, measuring 3.97 dB, 4.34 dB, and 5.66 dB for 0.123, 0.168, and 0.182 THz respectively. Additionally, the antenna demonstrates high efficiencies of 81.5%, 85%, and 91.2%, respectively. Hence, the suggested THz antenna will be useful for surveillance radar (123 GHz), medical imaging (168 GHz), and radio astronomy (182 GHz) applications
Substrate thickness variation on the frequency response of microstrip antenna for mm-wave application
Get PDFSubstrate height (Hs) is an important parameter that influences antenna propagation. This research designed a low-profile 28 GHz microstrip antenna on a polyimide substrate with varying Hs using CST Studio software. The simulated results and MINITAB software were used to develop regression model equations, which analyzed the impact of Hs variation on the antenna performance. The proposed models’ equations have indicated an increase in average responses of resonant frequency (Fr), percentage bandwidth (% BW), gain (G), return loss (RL), and efficiency (ƞ) as the Hs decreased. The antenna achieved a BW of 3.87 GHz at Hs 0.525 mm and 5.54 GHz at 0.025 mm, a G of 3.89 dBi at Hs 0.525 mm and 3.91 dBi at Hs 0.025 mm, and an ƞ of 94.19% at Hs 0.525 mm and 98.24% at Hs 0.025 mm. The antenna was fabricated and tested, and the experimental results were validated with the models’ equations. The thinner substrate resulted in an improvement in the antenna performance
A compact five-band patch antenna covering WLAN, WiMAX, X, and Ku-bands
Get PDFThis paper introduces a compact, low-profile, five-band antenna for wireless communication systems operating across 2.4/5 GHz WLAN, 3.5 GHz WiMax, and 7.5 GHz X- and Ku-band frequencies. The proposed antenna utilizes a novel configuration with a dual-overlapping rectangular patch coupled to a wide circular slot and an inverted L-shaped strip. Fabricated on a single-layer FR4 substrate (εr=4.3, thickness=1.6 mm), the antenna employs a 50-ohm coplanar waveguide feed, resulting in a compact footprint of 40×40×1.6 mm³. Experimental measurements and simulations demonstrate a bidirectional radiation pattern covering five distinct frequency bands: 2.4-2.485 GHz, 3.4-3.6 GHz, 5.15-5.825 GHz, 7.25-8.4 GHz, and 13.4-17.7 GHz. The antenna exhibits a return loss better than 10 dB across all bands and provides average gains of 1.78 dBi, 3.04 dBi, 3.4 dBi, 4.27 dBi, and 4.46 dBi, respectively. These results confirm the successful development of a five-band antenna with excellent performance characteristics, making it a promising candidate for 2.4/5 GHz WLAN, WiMax, and X- and Ku-band satellite communications, with automotive vehicles being one example
High-speed dividing device with the formation of quotient and remainder
Get PDFConsidered the possibility of accelerating the time-critical operation of division for multi-bit integers. This problem is significant since, so multi-bit integers are widely used in specialized devices, including cryptographic transformations. A method for high-speed quotient and remainder determination with optimal hardware costs is proposed. A preliminary increase in the divisor and its subsequent decrease by shifting it to the right are used. A structural diagram and functional diagram of the hardware implementation have been developed using high-speed combinational logic circuits. The device’s principle of operation, its step-by-step process, and specific examples illustrating its correct operation and resource efficiency are addressed. On average, it takes (k/2+1) clock cycles to obtain the result, where (k+1) bit capacity of the quotient. In most division schemes with optimal hardware costs, the number of clock cycles required to obtain the quotient (without remainder) is (k+1). High-speed division with simultaneous determination of several quotient bits requires (m/p) clock cycles for the division operation, where p- the number of simultaneously determined quotient bits, m-bit capacity of dividend. However, this approach will require additional hardware. The research will continue by modeling the device in Vivado Design Suite computer aided design (CAD) based on Artix-7 field programmable gate array (FPGA) from Xilinx
Energy scavenging-aided NOMA uplink communications: performance analysis
Get PDFEnergy scavenging-aided nonorthogonal multiple access (NOMA) networks significantly ameliorate energy-and-spectral efficiencies thanks to superimposing a multitude of user signals for concurrent transmission and harvesting radio frequency energy. Practically, energy harvesters possess non-linear characteristic and their efficiency is enhanced considerably with deployment of multiple antennas. Moreover, communication reliability and harvested energy are directly influenced by wireless propagation which induces simultaneous effects of shadowing, path loss, and fading. Accordingly, the current paper assesses analytically outage probability and throughput of energy scavenging (ES)-aided NOMA uplink communications (eNOMAu) taking into account the above-addressed realistic factors (κ − µ shadowed fading, multi-antenna deployment, ES nonlinearity). The results reveal considerable performance degradation caused by ES non-linearity and wireless propagation. Additionally, desired system performance can be reached flexibly with appropriate specification selection. In addition, accreting a quantity of antennas drastically mitigates the outage probability of eNOMAu, which can be minimized with optimal ES time selection. Furthermore, the proposed eNOMAu is considerably superior to its eOMAu counterpart
Hybrid Kolmogorov-Arnold and convolutional neural network model for single-lead electrocardiogram classification
Get PDFThis study proposes a hybrid Kolmogorov-Arnold networks (KANs) and convolutional neural networks (CNN) to classify electrocardiogram (ECG) signal abnormalities in one lead ECG data of wearable telemedicine. The hybrid model combines CNN to extract hierarchical features from sequential data and KANs to model non-linear relationships with fewer parameters as an efficient classification. The study explores the model’s capacity to balance accuracy, computational efficiency, and memory usage as critical factors for real-time health monitoring in resource-constrained environments on the single-lead MIT-Beth Israel hospital (MIT-BIH) Supraventricular Arrhythmia database with five different class labels. For comparison, standalone CNN and KAN models were also trained on the same balanced dataset. The CNN model achieved an accuracy of 96.62%, precision of 96.81%, and recall of 96.53%. The KAN model, while computationally efficient, performed less effectively, with an accuracy of 94.15%, precision of 95.01%, and recall of 92.57%. In contrast, our hybrid KAN-CNN model outperformed both, attaining an accuracy of 97.53%, precision of 97.66%, recall of 97.40%, and a low loss of 0.0840. The study also explores the impact of quantization and compression on model performance, revealing that both CNN and Hybrid KAN-CNN models retained high accuracy post-quantization, whereas the KAN model exhibited a more significant drop in performance
An extensive framework for assessing the quality of websites
Get PDFThe quality of the website is quite important in generating customer satisfaction and loyalty. A website’s quality depends on several factors, features, and characteristics. Several computational methods are necessary to evaluate the quality of each factor and subsequently determine the overall quality of the entire website. Each factor does not contribute to the same level of quality required by the end users and thus requires a weighting system. Expert systems, which are either manually defined or learnt using artificial intelligence (AI), are to be modelled for assessing the quality of a factor/sub-factor or characteristics of a sub-factor. The quality of a website varies depending on the context. Context-based quality assessment of the websites is required. There is a need to generate example sets to assess the quality of websites and to establish relationships between web-related quality factors, subfactors, and characteristics. In this paper, a comprehensive framework is presented that caters to parametric structure building and mapping, parsers for computing characteristic values, context assessment, building expert systems, and learning models for assessing the quality of websites and weighing the factors that have specific significance on the quality of the website