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Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel compact fractal loaded two- and eight-element multiple input multiple output (MIMO) with strong diversity is designed for 5G Sub 6 GHz and WLAN applications. The suggested antenna is designed and manufactured on inexpensive FR4 dielectric material with small size of 72 mm × 72 mm × 1.6 mm (0.792λ × 0.792λ × 0.0176λ, where λ is calculated at a lower operating frequency). The proposed layout features a partially grounded, protruding T-shaped stub on the underside of the substrate and a set of fractally loaded circular patch antenna elements on the top. Four triangular slots on the substrate and a T-shaped stub on the ground are employed to produce good isolation over the intended bands. The proposed antenna has a frequency range of (3.3–6.0) GHz, making it compatible with the 5G sub-6 GHz bands and the WLAN band thanks to its high isolation of above 15 dB and good impedance matching characteristics. Good agreement is observed between the antenna results and the theory of characteristic mode analysis approach. The designed antenna is well suited for 5G sub-6 GHz and WLAN communication applications due to its low ECC (0.005), total active reflection coefficient (TARC) (−10 dB), mean effective gain (MEG) (−3 dB), and diversity gain (DG) (−10 dB), channel capacity losses (CCL) (0.05), peak gain (>2.5 dBi), radiation efficiency (>95%), and stable boresight radiation patterns. [ABSTRACT FROM AUTHOR]

A dual‐band printed dipole array antenna for a wireless local area network (WLAN) application is presented. A radiation element consists of four pairs of printed dipoles, and two radiation elements are collinearly arrayed. A broadside coupling microstrip line‐based two‐sectional impedance transformer is used to feed the radiation elements in parallel. The proposed dual‐band antenna is designed to cover the dual‐frequency bands (2.4–2.48 and 5.15–5.825 GHz) which are the lower‐ and upper‐frequency bands for WLAN operation. The experimental results support the proposed design theory and also exhibit the gain values of 3.89–4.88 and 5.79–7.18 dBi at the lower‐ and upper‐bands, respectively, maintaining the omnidirectional radiation pattern. The measured radiation efficiencies at each frequency points, 2.4, 5.2, and 5.5 GHz are 87.39%, 75.43%, 69.96%, and 73.07% $ \% $, respectively. In addition, for mass production, the effect from a low‐cost flexible coaxial cable, and polyethylene housing on the antenna performance is also investigated in this letter. [ABSTRACT FROM AUTHOR]

A compact printed dipole antenna using an integrated balun is introduced in this work, which is achieved three frequency bands by using C‐shaped resonators. The total dimension of the proposed antenna is 42 × 72 mm2, and it covers the frequency bands of 1.62–1.88, 2.36–2.81, and 5.15–6.16 GHz with S11 < −10 dB. Furthermore, the measured peak gains of the antenna in three frequency bands are equal to 8.52, 9.46, and 6.81 dB, respectively. Dipole antennas with integrated baluns have a main frequency band based on the length of the dipole arms. Nevertheless, in the presented design, two additional frequency bands have been created for the antenna, by producing suitable magnetic couplings between the C‐shaped resonators and the Γ‐shaped feed line innovatively, which has a better radiation behavior, unlike traditional triple‐band antennas. An equivalent circuit of the introduced antenna has been investigated and afterward, the optimized antenna has been fabricated and tested. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a slotted printed rectangular monopole antenna (SPRMA) is proposed that covers the entire UWB (ultra‐wideband) except for WiMAX and WLAN (802.11/a‐n). In the first stage, a rectangular monopole antenna is designed, which covers the entire UWB frequency. Then, a T‐slot is inserted in the radiating patch to have the rejection of the band containing WiMAX and WLAN (802.11/a‐n). The notch characteristics of the proposed antenna are observed from 3.0 to 3.65 GHz and 4.5 to 6.65 GHz respectively. Measured peak gain of 3.28 dBi has been observed at 4.25 GHz frequency. To show the validation of antenna, mathematical analysis using circuit theory has been also given in the paper. The prototype has been also tested inside the anechoic chamber to give the validation in real‐time environment. Several other reported antenna structures have also the same notch band in UWB with different notching methods. The proposed structure's radiation properties are compared with other reported structures proving the compactness of the proposed structure. [ABSTRACT FROM AUTHOR]

Wireless Communication has become one of the most popular types of communication networks because of the many services it provides; however, it has experienced several challenges in improving network performance. VLAN (Virtual Local Area Network) is a different approach which enables a network administrator to create a logical network from a physical network. By dividing a large network into smaller networks, VLAN technology improves network efficiency, management, and security. This study includes VLAN for wireless networks with mobile nodes integration. The network protection was improved by separating the connections and grouping them in a way that prevents any party from being able to contact unauthorized stations in another party using VLAN. VLAN demonstrated restricted access to private server data by managing traffic, improving security, and reducing levels of congestion. This paper investigates the virtual local area network in a wireless network with three ad hoc routing protocols in a number of different scenarios, using the Riverbed Modeler simulation, which was used as a simulation program in this study. It was found from the investigation process that adopting VLAN technology could reduce delay and data of the network and considerably lower throughput, which is a major drawback of VLAN. Ad hoc routing algorithms, including AODV (Ad Hoc On-Demand Distance Vector), DSR (Dynamic Source Routing), and OLSR (Optimized Link State Routing) routing protocols, were used to improve the delay and throughput of the network. Routing methods with VLAN were tested across the WLAN to obtain the best throughput gain performance. The findings also revealed that these ad hoc routing protocols improved the Wireless Sensor Network performance as an additional investigation for the improvement of any network's delay and throughput. [ABSTRACT FROM AUTHOR]

In this article, a dual band frequency reconfigurable antenna is proposed for WiMAX and WLAN applications. Double-Square-Ring (DSR) shaped radiator is designed to exhibit dual mode operations and PIN diodes are implemented to switch the operating modes. Coaxial feed is selected to feed the antenna as the spurious radiation from it is minimal as compared with the microstrip feed. The current path along the radiating patch is affected with the ON and OFF conditions of the PIN diode which results in dual mode operation of the proposed antenna. The antenna is having a small footprint of 40 × 40 mm2 fabricated on a 1.6 mm thick FR-4 substrate. Presented antenna covers an impedance bandwidth of 52 MHz in WiMAX band (2.28 − 2.33 GHz) and 157 MHz in the WLAN band (5.1 − 5.28 GHz). This antenna's working principle is explained through current distribution diagrams along with design evolution. The experimental and simulated results are presented to validate the proposed antenna design. [ABSTRACT FROM AUTHOR]

The article presents a Co-planar Waveguide (CPW) fed antenna of a low-profile, simple geometry, and compact size operating at the dual band for ISM and WLAN applications for 5G communication devices. The antenna has a small size of 30 mm × 18 mm × 0.79 mm and is realized using Rogers RT/Duroid 5880 substrate. The proposed dual-band antenna contains a CPW feedline along with the triangular patch. Later on, various stubs are loaded to obtain optimal results. The proposed antenna offers a dual band at 2.4 and 5.4 GHz while covering the impedance bandwidths of 2.25–2.8 GHz for ISM and 5.45–5.65 GHz for WLAN applications, respectively. The proposed antenna design is studied and analyzed using the Electromagnetic (EM) High-Frequency Structure Simulator (HFSSv9) tool, and a hardware prototype is fabricated to verify the simulated results. As the antenna is intended for on-body applications, therefore, Specific Absorption Rate (SAR) analysis is carried out to investigate the Electromagnetic effects of the antenna on the human body. Moreover, a comparison between the proposed dual-band antenna and other relevant works in the literature is presented. The results and comparison of the proposed work with other literary works validate that the proposed dual-band antenna is suitable for future 5G devices working in Industrial, Scientific, Medical (ISM), and Wireless Local Area Network (WLAN) bands. [ABSTRACT FROM AUTHOR]

This work presents a wideband, all-side square-cut square patch multiple-input, multiple-output circularly-polarized (MIMO-CP) high-isolation antenna. The MIMO-CP antenna contains a two-port square cut on all corners of the square patch, and parasitic elements of 9 × 5 periodic square metallic plates are designed and operated. The outer dimensions of the antenna are 40 × 70 mm2, and the FR4 substrate height is 1.6 mm. The proposed antenna with the parasitic elements improves impedance matching and enhances S-parameters and axial ratio (AR). In the suggested MIMO-CP antenna, a parasitic element is designed and placed around the antenna periodically to reduce mutual coupling (MC) and improve CP. Simulated results show that the suggested antenna has a wide bandwidth (BW) from 4.89 to 6.85 GHz for S11 and was < −10 dB with AR ≤ 3 dB from 5.42 to 6.58 GHz, with a peak gain of 6.6 dB. The suggested antennas have more than 30 dB isolation and a low profile, are affordable, easily made, and are CP. To make a comparison with the measured and simulated results, a MIMO-CP antenna structure was fabricated and tested. The suggested antenna is better in terms of efficiency, envelope correlation coefficient (ECC), diversity gain (DG), channel capacity loss (CCL), and total active reflection coefficient (TARC). The proposed antenna is adequate for WLAN applications. [ABSTRACT FROM AUTHOR]

A novel elliptically slotted antenna (ESA), with two notched bands for Ultrawideband (UWB) applications, is presented. The ESA comprises of an elliptically slotted radiator with a beveled defected ground structure (DGS) for achieving UWB bandwidth ranging from 3.42 to 11.79 GHz (110%) for VSWR< 2. Two rejected bands at WLAN (5.02–5.97 GHz) and down link of X- band (7.23–7.72 GHz) applications are obtained by etching S-shaped slot in the microstrip feed line and an asymmetrical C- shaped parasitic stub above the DGS, respectively. The ESA is printed on FR-4 substrate with a compact size of 24 × 28 m m 2 and with a stable gain fluctuation from 2 to 4.08 dBi. A good matching, achieved in-between tested and simulated results, makes ESA to be a suitable candidate for WLAN/X-band-notched UWB applications. [ABSTRACT FROM AUTHOR]

In the paper, the BTS (Background Traffic Simulator) tool is proposed to capture network traffic and then reproduce it in a simulations using the ns-3 simulator extension module. This new method of generating background traffic allows for repetitive testing of simulation scenarios under real network conditions. The authors described the differences between the previously available methods and the proposed solution. The operation of all the most important elements of the proposed tool has been described. The influence of the generated background traffic on the simulation scenario was presented as well as the results of the operation. [ABSTRACT FROM AUTHOR]

In the era of continuous advancement in wireless technologies, path loss, also known as channel attenuation, is a drop in signal strength from the transmitter to the receiver. Path loss modelling is critical in designing fixed and mobile communication systems for various applications. This paper focuses on the received power (dBm) and free space path loss (FSPL) on various distances and frequencies such as 5240 MHz for wireless local area network (WLAN) and frequency such as 2100 MHz for the mobile network such as Celcom. As a result, able to analyze the correspondence between received power (dBm) and distance of each related frequency and the correspondence between FSPL (dB) and distance of each corresponding frequency and able to analyze the effect of obstacle on received power (dBm) and frequency. [ABSTRACT FROM AUTHOR]

Antennas play a crucial role in communication as they serve as both transmitters and receivers. They are capable of supporting numerous applications and demanding higher bandwidth among which monopole antennas have emerged as a superior alternative to traditional antennas. A novel coplanar waveguide (CPW)-fed triple-band monopole antenna is proposed for WLAN and WiMAX applications. The antenna features a compact and simple Cshaped strip structure, allowing for easy fabrication. The prototype exhibits triple operating bands covering the required bandwidths of 2.4/5.2/5.8 GHz WLAN and 3.5/5.5 GHz WiMAX standards. Good radiation performance and antenna gain are achieved across the three frequency ranges. Another compact monopole multiband antenna is designed, consisting of five rectangular patches forming a C-shaped structure. It operates at frequencies covering WiMAX, WLAN, short-range radar, and wireless data transmission applications. The antenna demonstrates significant bandwidth to accommodate the respective frequency ranges required for these applications. The antenna design is simulated using HFSS v13 software. [ABSTRACT FROM AUTHOR]

This paper describes a 2.4-GHz fully-integrated front-end receiver including a single-pole triple-throw (SP3T) switch and a low-noise amplifier (LNA) with bypass function, which was fabricated in a 0.25 μm GaAs pHEMT process. An asymmetrical SP3T switch architecture is incorporated to enable the receiver to operate in four modes. The exploration of impedance and voltage gain behavior of the proposed LNA help to establish the matching network and alleviate the trade-off between noise figure (NF) and gain performance. In LNA high gain mode, the implemented front-end receiver shows 1.7 dB of NF and 6dBm of input third-order intercept point (IIP3) with 20 dB of power gain drawing 11 mA of current from 5 V power supply at 2.4 GHz. All input and output return loss had exceeded 10 dB with fully on-chip impedance matching network. In bypass mode, the measured insertion loss of typically 7.5 dB is achieved. [ABSTRACT FROM AUTHOR]

This paper presents frequency and radiation pattern reconfigurable monopole antenna for WLAN and WiMAX applications. The reconfiguration of the proposed antenna is achieved using three switches. The working frequency bands of the antenna are controlled by one switch while adjusting the radiation pattern of the antenna is achieved by the other two switches. The antenna works at frequencies 3.5 and 5.5 GHz, covering the bands 3.5039-3.6073 GHz and 5.2601-5.9861 GHz, respectively. The required direction of radiation has been obtained by changing the state of some switches. The suggested antenna has several benefits, including its small size, frequency and pattern reconfigurability with only three switches, which reduces the biasing network's complexity significantly. The suggested antenna is operated in five modes and two frequency bands. In all circumstances, the suggested design provides a perfect voltage standing wave ratio. For verification purposes, the suggested antennas are built and measured at several switch locations and good agreements with the simulation are achieved. [ABSTRACT FROM AUTHOR]

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A compact printed antenna with three rejected bands has been examined and presented in this manuscript. This antenna is fed by a coplanar waveguide and operates over a wide range of frequencies. An arc-shaped, rectangular strip like and split-ring slot have been etched from the designed radiating patch to generate the rejection peaks at Wi-MAX, WLAN and X-band satellite communication. Primarily, the rectangular patch has been considered and further this patch is modified to acquire the UWB frequency spectrum from 3.1 to 10.6 GHz. The overall size of designed antenna is 27 × 27 × 1.6 mm3 which comprises of novel structure of radiating patch and 50Ω CPW feed. After modification the final geometry of radiating patch, proposed antenna divulges the VSWR bandwidth of 11.88 GHz (2.12–14.0 GHz). Further, by introducing different types of slots in the final structure of radiating patch antenna exhibits Wi-MAX (3.16–3.76 GHz), WLAN (5.26–5.87 GHz) and X-band satellite communication (7.30–7.68 GHz) rejected bands. Furthermore, designed UWB antenna embellishes the gain of −7.64 dBi, −4.80 dBi and −4.92 dBi at rejected bands, whereas, the gain of antenna at other frequencies varies between 3.65 and 8.19 dBi. Proposed UWB antenna exemplifies the radiation efficiency variation in 77–98% except notched frequency bands. The radiation pattern and group delay of antenna is also at the acceptable level for existing UWB applications. Lastly, final optimized geometry of antenna with three band notched characteristics is being fabricated and verified for the validation of simulated results. Both the results are related and are found in good agreement with each other and also divulged that proposed antenna is eligible candidate for UWB applications with band rejection characteristics. [ABSTRACT FROM AUTHOR]

A new compact and modified hexagonal-shaped circular MIMO antenna that operates in the band of 2.95–6.3 GHz is presented in this paper. This antenna covers the complete range of 5G sub: 6 GHZ (N77/N78 & N79) and WLAN bands. The design consists of two element MIMO antenna fabricated on low cost FR-4 substrate. In order to improve the isolation a vertical stub is placed between two elements. Isolation greater than 15 dB is achieved over the entire operating band. The suggested MIMO antenna is excited using an asymmetric feeding approach. Simulated and measured results from fabricated prototypes are in good agreement. Results confirm the diversity and radiation performance of the proposed MIMO antenna are good. The diversity metric parameters ECC, DG, TARC, CCL, and MEG values strongly agree. The construction is created on a FR4 substrate with dimensions of 20 × 34 mm2, 1.6 mm in height, and 4.4 as the constant. The structure has efficiency and gain values of above 83% and 0.2–3 dBi, respectively. [ABSTRACT FROM AUTHOR]

This article presents a low-profile and flexible dualband AMC Antenna operating at 2.45/ 5.8 GHz for wireless local area network (WLAN) on-body antenna applications using textile materials. A dual-band artificial magnetic conductor (AMC) structure with a dual hexagonal shape was used to reduce back radiation, therefore specific absorption rate (SAR), and improve the antenna performance parameters. To study the antenna/body interaction, a suitable comprehension and detailed studies of the wave propagation in the vicinity of the human arm in different meteorological conditions were carried out to demonstrate the effects of the skin condition on the antenna performance parameters. The simulation and measurement results indicate that electromagnetic communication on wet skin is viable. Acceptable SAR values were obtained, revealing that the body is well immune from the antenna electromagnetic radiation in functional wearable conditions. The proposed wearable AMC antenna provided engaging simulation and measurement results. It satisfies users' comfort and safety properties, making it a good candidate for WLAN/WBAN applications.

A fully-differential compact and tunable second-order bandpass filter (BPF) with high quality factor using a novel active inductor (AI) has been proposed for 3.6 GHz WLAN applications. The proposed AI employs a differential amplifier as a feedforward transconductor and a common-source (CS) transistor as a feedback transconductor in a symmetrical configuration. The combination of a cascode scheme and a resistor in the feedback path enhances the quality factor of the AI, thereby increasing the mid-band gain of the BPF. In order to achieve independent tuning of both the center frequency and mid-band gain of the BPF, a varactor capacitor is utilized. The proposed second-order BPF is designed with a center frequency and a bandwidth of 3.675 GHz and 10 MHz, respectively. Post-layout simulation, process corner, and temperature sweep analysis results are conducted with 65 nm CMOS technology at 1.2 V supply voltage. The proposed filter has a tuning range of 3.655–3.695 GHz and attains a mid-band gain of 67.5 dB, a noise figure of 14.5 dB, and a 1-db compression point of −12.39 dBm. Additionally, the BPF consumes a DC power of 1.22 mW and occupies an active area of only 8.85 μ m × 10.3 μ m. • A novel active inductor-based bandpass filter has been proposed for WLAN application. • Active inductor's unique differential structure reduces area and power consumption. • Utilizing cascode transistor and feedback resistor leads to improved quality factor. • A varactor enables tuning the center frequency and mid-band gain of the filter. • The bandpass filter excels in selectivity, power consumption, and chip size. [ABSTRACT FROM AUTHOR]

This paper proposes an eight-element dual-band multiple-input multiple-output (MIMO) antenna that operates in the fifth generation (5G), n78 (3400–3600 MHz), and WLAN (5275–5850 MHz) bands to accommodate the usage scenarios of 5G mobile phones. The eight antenna elements are printed on two long frames, which significantly reduce the usage of the internal space of the mobile phone. Each antenna element is printed on both surfaces of one frame, which consists of a radiator on the internal surface and a defected ground plane on the outer surface. The radiator is a rectangular ring fed by a 50 Ω microstrip line which is printed on the top surface of the system board. A parasitic unit is printed on the outer surface of each frame, which is composed of an inverted H-shaped and four L-shaped patches. Each parasitic unit is connected to the internal surface of the frames through a via, and then it is connected to a 1.5 mm wide microstrip line on the top surface of the system board, which is connected to the ground plane on the bottom surface of the system board by a via. Four L-shaped slots, four rectangular slots, and four U-shaped slots are etched onto the system board, which provides good isolation between the antenna elements. Two merged rectangular rings are printed on the center of each frame, which improves the isolation further. The return loss is better than 6 dB, and the isolation between the units is better than 15 dB in the required working frequency bands. In addition, the use of a defected ground structure not only makes the antenna element obtain better isolation but also improves the overall working efficiency. The measurement results show that the proposed MIMO antenna structure can be an ideal solution for 5G and WLAN applications.

This article describes the development of a compact microstrip bandpass filter (BPF) for multiple wireless communication utilizations. The proposed bandpass filter consists of metamaterial unit cells that are symmetrical in shape. The design process involves the placement of four symmetrical split-ring resonators (SRRs) on the top plane of the BPF. It exhibits improved filter characteristics through the implementation of these SRRs. The filter was modeled and fabricated and its performance was evaluated using a Vector Network Analyzer. The designed bandpass filter shows a 5 GHz bandwidth covering the frequency band spanning from 1 to 5.2 GHz, with a quality factor value of 1.85 across 1.9 GHz, 3.3 across 3.3 GHz and 5.1 across 5.1 GHz. The metamaterial analysis was carried out using ANSYS ELECTRONIC DESKTOP. The proposed filter measures 20 × 18 × 1.6 mm3, which is significantly smaller than current filters. The designed bandpass filter occupies 50% of the space of a conventional filter. The designed bandpass filter exhibits a distributed surface current of 84 A/m, and 94 A/m across the wide- and narrow-band operating frequency. The simulated and measured results indicate that the suggested metamaterial filter is well-suited for multiband wireless applications like GPS (1.57 GHz), WLAN (2.4, 3.6, and 5.2 GHz), Wi-MAX (2.3, 2.5, and 3.5 GHz), and ISM (2.5 GHz).

Security identification solutions against WLAN network attacks according to straightforward digital detectors, such as SSID, IP addresses, and MAC addresses, are not efficient in identifying such hacking or router impersonation. These detectors can be simply mocked. Therefore, a further protected key uses new information by combining these simple digital identifiers with an RF signature of the radio link. In this work, a design of a convolutional neural network (CNN) based on fingerprinting radio frequency (RF) is developed with computer-generated data. The developed CNN is trained with beacon frames of a wireless local area network (WLAN) that is simulated as a result of identified and unidentified router nodes of fingerprinting RF. The proposed CNN is able to detect router impersonators by comparing the data pair of the MAC address and RF signature of the received signal from the known and unknown routers. ADAM optimizer, which is the extended version of stochastic gradient descent, has been used with a developed deep learning convolutional neural network containing three fully connected and two convolutional layers. According to the training progress graphic, the network converges to around 100% accuracy within the first epoch, which indicates that the developed architecture was efficient in detecting router impersonations.