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A Multi-Channel Man-in-the-Middle (MC-MitM) attack is an advanced form of MitM attack, characterized by its ability to manipulate encrypted wireless communications between the Access Point (AP) and clients within a WiFi network. MC-MitM attacks can target any Wi-Fi client, regardless of the authentication method used with the AP. Notable examples of such attacks include Key Reinstallation Attacks and FragAttacks, which have impacted millions of WiFi systems worldwide, especially those involving Internet of Things devices. Current defense mechanisms are inadequate against these attacks due to interoperability challenges and the need for modifications to devices or protocols within the targeted Wi-Fi networks. This paper introduces a distributed and cooperative signature-based wireless intrusion detection mechanism designed for online passive monitoring to detect malicious traffic patterns during MC-MitM attacks in any environment, from apartments and houses to large areas like hotels, offices or industrial sites. We implemented the proposed framework on Raspberry Pis and evaluated it in real-world settings. Our evaluation demonstrates that this framework can effectively identify MC-MitM attacks with an average accuracy of 98% when deployed across different locations within our experimental testbed. [ABSTRACT FROM AUTHOR]

A low-profile dual U-shaped monopole antenna designed for WLAN, WiMAX, and C-band applications has been implemented in this paper. The proposed antenna has covering frequency ranges of 2.7-3.1 GHz, 4.0-5.2 GHz, and 5.9-6.4 GHz. The compact antenna's antenna size is 24×30×0.8 mm², and the antenna has achieved bandwidths of 13.79%, 26.67%, and 8.1% across the respective bands. This frequency band is achieved as a result of dual inversion to each other in U shape. The low profile of the proposed antenna enables its easy and fast inculcation in modern communication devices. [ABSTRACT FROM AUTHOR]

A novel compact rectangular fractal-shaped antenna for tri-band wireless communication applications is developed in this article. The proposed fractal shaped is achieved by cutting two rectangular slots in the rectangular monopole. Additionally, a stub is introduced in the bottom side of the antenna to enhance the impedance bandwidth of the acquired three bands. The developed antenna has a compact size 22 × 34 × 1.6 mm3. The CST MWS is used to design the antenna and its characteristics including S11, current distribution, radiation characteristics are exposed and analysed. To demonstrate that the simulation outcomes are reliable, the suggested antenna is manufactured and put through testing on an E5071C VNA. Additionally, the results of the experiments demonstrate that the designed antenna offers three impedance bandwidths 2.25–2.96 GHz, 3.56–4.01 GHz, and 4.6–5.86 GHz, which shields all the LTE, WLAN, WiMAX, and C-band applications. The proposed tri-band fractal antenna also provides good gain at the operating frequencies and an omnidirectional radiation pattern. [ABSTRACT FROM AUTHOR]

A simple and compact polarization reconfigurable patch antenna design is proposed to operate in WLAN band at a resonant frequency of 2.4 GHz. This antenna consists of a rectangular patch placed on an FR4 substrate. A rectangular slot is cut in the rectangular patch. Two L shaped microstrip strips are placed inside the slot and joined together at the centre of the rectangular patch by inverting the L shaped microstrip. There are three different methods of achieving the reconfigurability namely electrical, mechanical and optical. This proposed structure uses electrical reconfiguration technique. This proposed antenna structure uses PIN diodes for achieving the polarization reconfigurability because of its ease in biasing. Two PIN diodes both being placed on the inverted L shaped structure in order to achieve the polarization modes and these PIN diodes are used to connect this microstrip with the rectangular patch. By switching these two PIN diodes for various biasing conditions, four different polarization modes namely two linear polarization (LP) modes, one Left Hand Circular polarization (LHCP) and one Right Hand Circular polarization (RHCP) mode is achieved. The antenna produces simulated gain of around 1.5416 dB for LP1 mode at 2.41 GHz, 1.7175 dB for LP2 mode at 2.45 GHz, 1.6062 dB for RHCP mode and 1.5922 dB for LHCP mode both at 2.4 GHz. The antenna structure is simulated using Ansys HFSS. [ABSTRACT FROM AUTHOR]

In this work, varoius dual-band WLAN MIMO antennas are designed and implemented. Measuremnet Results show that the working bands of these antennas are (2.40–2.48) GHz and (5.1–6.0) GHz. Metallic barrier are used to increase isolation among the ports of the WLAN MIMO antennas. For the two elements WLAN MIMO antenna with parrallel feed, isolation between ports of this antennas is higher than 18 dB. For the 2*2 (four) elements WLAN MIMO antenna with parrallel feed, isolation between ports of this antennas is higher than 19 dB. [ABSTRACT FROM AUTHOR]

The demand of IEEE 802.11 based Wireless Local Area Network (WLAN) is increasing in enterprises, homes, and public access areas primarily due to its high data rates, low cost, and ease of installation. While WLAN continues to be predominantly data-centric, the necessity of Voice over Internet Protocol (VoIP) over Wireless Fidelity (WiFi) or VoWiFi cell capacity analysis in infrastructure-based WLAN plays a vital role. We employed arbitration inter-frame space (AIFS) for assessing channel state before sending real-time data from one user equipment to another, and short inter-frame space (SIFS) for transmitting Request To Send (RTS), Clear To Send (CTS) and Acknowledgement (ACK) frames to study the VoWiFi cell capacity. We have proposed analytical approaches to estimate the cell capacity of an IEEE 802.11be WLAN standard Assess Point (AP) providing VoWiFi service considering well known vocoders such as G.723.1 and G.729. To minimize the call bandwidth, we employed the compressed RTP (cRTP) protocol. Additionally, we examined the impact of retransmission on cell capacity of a WLAN standard providing VoWiFi service. [ABSTRACT FROM AUTHOR]

In this research, a quad‐band sickle‐shaped MIMO antenna of compact size 32 × 32 mm2 (0.28λ0 × 0.28λ0 at lower resonant frequency 2.6 GHz) has been proposed using partial ground and tilted isolation stub at an angle of 45°. It covers 2.40 to 2.80 GHz frequency range with bandwidth (BW) of 15.38% (0.40 GHz) which is applicable for Wi‐Fi application in first band and in second band it covers from 4.48 to 5.75 GHz frequency range with BW of 24.83% (1.27 GHz) for WLAN application. In addition, the third band starts from 9.75 to 10.43 GHz frequency range with BW of 6.74% (0.68 GHz) for the X‐band whereas in fourth band it covers from 13.07 to 15.87 GHz frequency range with BW of 19.38% (2.8 GHz) frequency, which is applicable on Ku‐band application. Moreover, the isolation is < −15 dB in the entire resonating frequency band which is an acceptable limit for reduction of mutual coupling. ECC value is <0.5 in the entire operating band of frequency. The diversity gain of the proposed MIMO antenna is approximately 9.96 dB that shows the antenna exhibits good diversity property. The channel capacity loss value is <0.4 bps/s/Hz in the entire resonating band. In view of all the diversity parameters, the proposed MIMO structure fulfills all the requirements of the MIMO antenna. [ABSTRACT FROM AUTHOR]

In this paper, a CPW-fed compact antenna with tri-band reject characteristics is presented and experimentally verified. A curved ground plane is introduced to enhance the bandwidth to 250 MHz. The sectoral patch antenna has a T-strip and Y-slot to reject WLAN (4.78 ∼ 5.68 GHz) and WiMAX (3.385 ∼ 3.97 GHz), respectively. L-strips are placed in the ground plane to increase the bandwidth as well as the plane to reject uplink satellite frequency in the X-band (7.93 ∼ 8.74 GHz). In all notch bands, high VSWR values are observed. The structure is compact with a size of 15 × 12 × 0.8 mm3. To study the effect of strip/slot on VSWR, parametric analysis is done. The notch frequency is theoretically calculated by an empirical formula. The measured result validates the simulated and calculated notch frequencies. [ABSTRACT FROM AUTHOR]

In this article, an F-shaped four-port multiple-input multiple-output (MIMO) antenna is designed and analyzed. In the designed antenna for achieving high isolation, we introduced a novel isolation technique that appears like plus-shaped wall placed in between the antenna elements. The antenna is designed on a low-cost FR-4 epoxy substrate with total dimensions of 0.61 $ \lambda _{0}\times 0.61\lambda _{0}\times 0.03\lambda _{0} $ λ 0 × 0.61 λ 0 × 0.03 λ 0 (31 mm × 31 mm × 1.58 mm) where $ \lambda _{0} $ λ 0 is the free space wavelength at 5.8 GHz and experimentally verified. This MIMO antenna design covers operating the range of frequencies 5.47–6.20 GHz ( $ |S_{11}| \lt - $ | S 11 | < − 10 dB) which provides a bandwidth of 730 MHz. In terms of performance, the proposed antenna achieves high isolation of $ \lt -45.52 $ < − 45.52 dB with an improved reflection coefficient of $ -30.44 $ − 30.44 dB, a peak gain of 3.77 dBi and a radiation efficiency more than 82% across the entire operating band. Moreover, the achieved MIMO diversity parameters of the proposed antenna are envelope correlation coefficient < 0.005, diversity gain $ \lt 9.99 $ < 9.99 dB, mean effective gain $ \lt -3 $ < − 3 dB and total active reflection coefficient $ \lt -10 $ < − 10 dB in the operating band of frequency. The simulated and measured results show a good agreement between them. Finally, after analyzing the performance of the proposed MIMO configuration, we can say that this antenna is suitable for C-band, WiMAX, Wireless-Fidelity (Wi-Fi), Wireless Local-Area Network (WLAN), Bluetooth and Industrial, Scientific, & Medical (ISM) bands applications. [ABSTRACT FROM AUTHOR]

A wide variety of driver safety, comfort, and infotainment systems are available in modern cars, many of which rely on wireless connectivity. This article introduces a modified square-shape MIMO antenna designed for vehicle-to-everything (V2X) communications. The design of the antenna operates for WiMAX, WirelssLAN, frequency bands which possess a compact size of 60 mm × 40 mm × 0.256 mm. The antenna utilizes modified square shape stubs and defected ground and achieves dual-band resonance by using circular shapes at the corners and a slot in the center position. The rectangular and circular slots enable resonance at 4.3 GHz & 5 GHz, and also has a low impedance matching with better radiation of omnidirectional patterns. It was determined that the MIMO antenna under consideration reaches a maximum gain of 6.5 dB and 4 dBi at 4.3 GHz and 5 GHz, respectively. When tested at theta = 30° and phi = 90°, this MIMO antenna shows very little backward radiation, exactly −5 dB. The authors have attained reliable communication by fine-tuning the structural parameters of the antenna to achieve the desired passband performance. Furthermore, virtually placing the antenna on a car model and analyzing its performance in a realistic scenario has enabled them to determine the antenna's effectiveness in real-world applications. The authors have also presented better simulation results. This approach provides experimental evidence of the antenna's performance and validates the results, ensuring the proposed antenna meets the required specifications. The article provides a robust analysis of proposed design of the antenna for vehicular communications. [ABSTRACT FROM AUTHOR]

This research presents an innovative dual-band microstrip patch antenna design enhanced with defected ground structures (DGS) and barium strontium titanate (BST) thin film, tailored for wireless local area network (WLAN) and WiMax applications. The first design phase involved the development of an microstrip patch antenna (MPA) using an flame retardant (FR4) substrate with a permittivity (er1) of 4.3 and a thickness of 1.524 mm, enhanced with DGS. This configuration achieved a single-band resonance at 4.1 GHz, with a bandwidth of 0.82 GHz and a return loss (S11) of -32 dB. The second phase involved the integration of a BST thin film, with a high permittivity(er2) of 250 and a thickness of 0.1 mm, into the DGS-enhanced microstrip patch antenna (MPA). This modification led to a transformation in the antenna's performance, enabling dual-band operation at resonance frequencies of 2.8 GHz and 5.8 GHz. Further, there was a corresponding substantial increase in bandwidth to 1.34 GHz and 1.25 GHz, respectively, an improvement in S11 values to -16.3 dB and -21.4 dB. Moreover, and antenna's size of 14×10×1.524 mm³. The study underscores the critical role of innovative material use and design optimization in advancing antenna technology, offering significant enhancements in bandwidth, and miniaturization, for wireless communication systems. [ABSTRACT FROM AUTHOR]

This study uses annular circular rings to create multi-band applications using crescent-shaped patch antennas. It is designed to be made up of five circular, annular rings nested inside of each other. Three annular rings are positioned and merged on top of the larger rings, with two annular rings set along the bottom of the feed line. The factors that set them apart, such as bandwidths, radiation patterns, gain, impedance, and return loss (RL), are analysed. The outcomes show how compact the multi-band annular ring antenna is. The proposed circular annular ring antenna has return losses of −33 dB and operates at two frequencies: 3.1 GHz and 9.3 GHz. This design is modelled and simulated using ANSYS HFSS. The outcomes of the simulation and the tests agree quite well. The X band and WLAN resonant bands have bandwidth capacities of 500 and 4300 MHz, respectively. Additionally, the circular annular ring antenna design is advantageous for most services at these operating bands. [ABSTRACT FROM AUTHOR]

A novel, compact, monopole apple-shaped, triple-band metamaterial-printed wearable antenna backed by a uniplanar compact electromagnetic bandgap (UC-EBG) structure is introduced in this paper for wearable wireless and medical body area network (WBAN/MBAN) applications. A tri-band UC-EBG structure has been utilized as a ground plane to minimize the impact of antenna radiation on the human body and improve antenna performance for the proposed wearable antenna. Metamaterial triangular complementary split ring resonators (TCSRRs) are incorporated into the antenna and UC-EBG structure, resulting in a compact UC-EBG-backed antenna with an overall size of 39 × 39 × 2.84 mm3 (0.41 λg × 0.41 λg × 0.029 λg). The printed textile antenna operates at 2.45 GHz for the wireless local area network (WLAN), 3.5 GHz for 5G new radio (NR), and 5.8 GHz for the industrial, scientific, and medical (ISM) bands with improved gain and high-efficiency values. Furthermore, the performance of the antenna is analyzed on the human body, where three models of curved body parts are considered: a child's arm (worst case) with a 40 mm radius, an adult's arm with a 60 mm radius, and an adult's leg with a 70 mm radius. The results demonstrate that the proposed antenna is an attractive candidate for wearable healthcare and fitness monitoring devices and other WBAN/MBAN applications due to its compact size, high performance, and low SAR values. [ABSTRACT FROM AUTHOR]

The wireless and portable equipment demand for boosting the data rate, spectral efficiency, coverage, SNR, and capacity which is fulfilled by MIMO antenna technology. In this research 4 elements hexagonal shaped antenna using MIMO techniques is designed for 2.1 GHz mobile and wireless applications. The antenna has four ports with identical radiators with hexagon shape. The special designed manifold arms of the proposed antenna design provide low correlation among the radiators. The inter-port isolation greater than 15 dB is achieved. The other MIMO antenna parameters like ECC is < 0.08 and the diversity gain is 10 dB in considered in 2:1 VSWR band. The proposed design ensures lower than 0.5 W/kg specific absorption rate (SAR), 3.0 dB mean effective gain (MEG) and 0.4 bits/s/Hz channel capacity loss (CCL). The peak gain of the antenna is 0.45 dBi at resonance. The E-field shows a maximum magnitude/major lobe in the direction of 190 °. The H-Field shows the major radiation in the direction of 187 °. The CST-MWS antenna designing tool is used to simulate and optimize the proposed design and it fabricated on FR-4 substrate. The research focuses on various parameters associated with MIMO antenna viz SAR, S-parameters, envelop correlation coefficient (ECC), radiation patterns, CCL, Diversity Gain surface current distribution, and MEG. [ABSTRACT FROM AUTHOR]

In recent years, microwave filtering technologies have known great advancement and wide employment in wireless communication systems, necessitating the development of miniaturization techniques to respect the size limitation in wireless communication devices and reduce the cost, in order to satisfy the consumer and be more competitive. Accordingly, the design of a microwave filter is chosen based on its electrical performance, size, and manufacturing price. Therefore, it is necessary to make a good compromise between the mentioned criteria to satisfy the industrial requirements. This paper proposes a small and inexpensive bandpass filter (BPF), where the proposed structure is carefully constructed over a low-price FR4 Epoxy substrate with a full dimension of (17.6 × 9 × 1.6) mm3. The proposed filter offers good electrical performance in terms of reflection coefficient (S11), insertion loss (S21), Voltage Standing Wave Ratio (VSWR), and selectivity. A filter prototype is fabricated and tested to affirm the simulation results. Consequently, the measured results show a good agreement with the simulation, proving the suitability of the proposed filter for different wireless applications, including WLAN, Bluetooth, ZigBee, RFID, and ISM bands. [ABSTRACT FROM AUTHOR]

Network traffic and load are only expected to increase. Data is lost while being sent between nodes and devices as a result of traffic congestion at bottlenecks. WLANs are becoming the go-to technology for access in hotspot locations, workplaces, and residences. A station in a wireless local area network may be able to connect to several access points (APs). So, deciding which AP is "optimum" from a selection of potential candidates is a pertinent question. The user merely associates the AP with the strongest received signal strength while using IEEE 802.11. But this could lead to a substantial load imbalance among a number of APs. With only a minor modification to the load distribution mechanism, adopting load balancing can improve efficiency and utilization in addition to reducing processing delays. To increase the effectiveness of the WLAN, we provide a dynamic load balancing strategy in this paper. The network and user overhead will be reduced by the suggested dynamic strategy. The suggested method utilizes network load and throughput as performance criteria for performing load balancing. The method's viability is checked using Riverbed Modeller Simulator. The experimental findings validate the effectiveness of the proposed technique in enhancing network throughput and reducing access point congestion. [ABSTRACT FROM AUTHOR]

This paper reports multiband microwave access multiple-input-multiple-output (MIMO) four-port antenna for UWB-X (3.10–12.0 GHz) band applications radiating electromagnetic energy with dual notched bands and compact size of 0.68λo × 0.92λo. Two notched bands are introduced on the radiating patch of the antenna and microstrip feed line mitigating Wireless-Local-Area-Network (WLAN: 5.11–5.88 GHz) & Downlink-Uplink Satellite (DUS: 7.28–8.36 GHz) interference. The technology reported includes simulated results and is validated by comparing the measured results of the 4 × 4 MIMO antenna. The mutual coupling between the radiating patch is suppressed below −15.0 dB which is achieved by interconnecting the ground and placing a cross-shaped parasitic patch between the radiating elements. The proposed MIMO antenna offers maximum gain efficiency of 5.92dBi & 0.95 (95%), respectively. The diversity parameters (ECCmax = 6 × 10−4, DGmax = 9.99 dB, TARCmax = −27.0 dB, CCLmax = 0.015b/s/Hz, MEG $ \approx $ ≈ −3.0 dB) are in the permissible range given by International Telecommunication Union (ITU) for information and communication technology. [ABSTRACT FROM AUTHOR]

A low-cost three-port series-fed antenna array with pattern diversity for WLAN applications is presented. The three antennas resonate at 5.8 GHz with 12 dBi antenna gain. The antenna substrate consists of an air cavity within the substrate, which is introduced to enhance the gain and radiation efficiency. The principle of micromachining was used to realize the substrate characteristic that lowers the dielectric constant, compared to a conventional non-micromachined substrate. The antenna uses scaled parasitic patches as a superstrate to improve and equalize the gain of the respective antennas when the antenna beam scans through +180, 00, and −180. The parasitic patches as a superstrate were found to have low scanning loss when the antenna beam is tilted from the broadside. The proposed superstrate design enhances the gain at the broadside and oblique radiations making the design more versatile as the gain enhancement becomes invariant to the incidence angle. The planar superstrate enhances the gains of three antennas with 2.4, 2.8, and 7.1 dB so that the final antenna gain is equalized to 12 dBi at the three ports. To validate the design, the antenna module is fabricated on the polylactic acid (PLA) substrate using the industry-standard photolithography process. [ABSTRACT FROM AUTHOR]

As a simple and inexpensive channel characteristic, received signal strength (RSS) finds extensive usage in localization applications. However, the quick changes in signal strength impact the localization precision. By averaging over access points (APs) with multiple frequencies and/or heights, this article suggests a novel approach to lowering RSS fluctuation. Initially focused on the plane-earth loss model, the study was later extended to include a multipath indoor propagation scenario that was simulated. We used ray-tracing software to model the indoor propagation situation. This research takes into account the results of three distinct methods for averaging RSS: height averaging, frequency averaging, and hybrid frequency and height (FH) averaging, which combines the two. We discovered that the Height-only strategy considerably decreased the RSS variation with distance for both settings we looked at. Using the frequency-only method even further reduced the variation. Using the Hybrid FH technique greatly enhances the results. Root mean square error values of 4.427 dB, 3.70 dB, and 3.5 dB, respectively, are provided for the averaging approaches and the ideal scenario in which no variance occurs. Another finding is that averaging with APs that have double the height or frequency will not improve the RSS distance variation. [ABSTRACT FROM AUTHOR]

With the wide applications of the Internet of Things (IoT) in smart home systems, IEEE 802.11n Wireless Local Area Networks (WLANs) have become a frequently chosen communication technology due to their adaptability and affordability. In a high-density network of devices such as the smart home scenerio, a host often meets interferences from other devices and unequal Received Signal Strength (RSS) from Access Points (APs). This results in throughput unfairness/insufficiency problems between hosts communicating concurrently in WLAN. Previously, we have studied the throughput request satisfaction method to address this problem. It calculates the target throughput from measured single and concurrent throughputs of hosts and controls the actual throughput at this target one by applying traffic shaping at the AP. However, the insufficiency problem of maximizing the throughput is not solved due to interferences from other hosts. In this paper, we present an extension of the throughput request satisfaction method to maximize the throughput of a high-priority host under concurrent communications. It recalculates the target throughput to increase the actual throughput as much as possible while the other hosts satisfy the least throughput. For evaluations, we conduct experiments using the test-bed system with Raspberry Pi as the AP devices in several topologies in indoor environments. The results confirm the effectiveness of our proposal. [ABSTRACT FROM AUTHOR]

In order to improve the communication quality and transmission rate of WLAN, the key technologies of smart antenna in WLAN based on adaptive array are proposed. The adaptive array is used to suppress the WLAN interference signal, and the feedback from the output is used to adjust the weight loaded on the signal, and the optimal weight corresponding to the linear constraint minimum variance is obtained to achieve beamforming optimization. On this basis, the optimal antenna selection algorithm and the sub-optimal antenna selection algorithm are designed, and the sub-channel matrix with the maximum capacity can be obtained by repeated iterative calculation, so as to realize the smart antenna selection and further optimize the performance of WLAN. Experimental results show that the smart antenna signal has 100% coverage in WLAN compared with conventional methods. When the transmission rate is greater than 35 mb/s, the delay of the study method is not jitter compared to the contrast method. When the transmission rate is greater than 35 mb/s, the packet loss rate of the proposed method remains stable, while the packet loss rate of the two comparison methods begins to increase. When the transmission rate is greater than 12 mb/s, the throughput of the proposed method is more stable than the other methods. In conclusion, this method has the characteristics of large signal coverage, low delay, low packet loss rate and high throughput, and can be widely used in practice. The contribution of this study is that the weight of the antenna array can be dynamically adjusted through the adaptive algorithm, thus optimizing the quality of the received signal and improving the receiving sensitivity. [ABSTRACT FROM AUTHOR]

This paper presents a source degenerated cascode low noise amplifier (LNA) design using a regulated cascode active inductor (AI). The AI has an inductance value of up to 6.28 nH, a Q-value of up to 4750, and a resonant frequency of up to 9.758 GHz. The proposed AI replaces the passive source degenerated inductor and load inductor in the LNA. Further, an active balun is used to have a differential signal at the LNA output to support the mixer stage. The gain and noise figure of the LNA is 22.2 and 5.6 dB respectively. The 3rd order input intercept (IIP3) value is 1.92 dBm and the return losses at the input port and two output ports are less than −10 dB. The power consumption of the circuit is 27 mW at a 1.8 V supply and the figure of merit (FoM) is 9.17. The area occupied by the AI is 39 × 72 µm2 and balun-LNA is 0.872 × 0.62 mm2. The complete proposed circuit is meant for wireless local area network (WLAN) applications in the 2.4 GHz frequency band. [ABSTRACT FROM AUTHOR]

In this work, we integrated narrow band (NB) and Ultra-Wide Band (UWB) four-port MIMO antennas designed and implemented in IoT applications. The designed antenna consists of two quarter-wavelength asymmetrical NB radiators and a reverse P-shaped UWB radiator. The two NBs are generated by two quarter-wavelength non-identical radiators, and the UWB is generated by a semi-circle-shaped monopole radiator. Further, the NB radiators and UWB radiators are connected in a 3-mm-wide feed line. The antenna is designed to operate at 1.8 GHz (3G), 2.4 GHz (WLAN), and 3.1–12 GHz (UWB) for IoT applications. In this designed four-port MIMO antenna, two proposed NB and UWB radiators are mounted on the front side of the FR4 substrate and the other two on the rear side of the FR4 substrate. The proposed MIMO antenna has a dimension of $ 65 \times 65 \times 1.6\,{\rm mm}^3 $ 65 × 65 × 1.6 mm 3 . The antenna performance and MIMO performance are analyzed. The diversity metrics such as ECC, DG, TARC, MEG, and CCL are computed, and their values are 0.26, 9.87 dB, −22 dB, −6 dB, and 0.27 bits/Hz/s, respectively, within the bounds. The real-time implementation of the designed antenna is demonstrated at 2.4 GHz for smart home applications. [ABSTRACT FROM AUTHOR]

In this paper, a reconfigurable 2×2 and 4×4 MIMO antenna is designed for UWB X-band wireless applications. The proposed design uses square patch radiating electromagnetic energy and a novel ground structure and consists of a reconfigurable module enabling to set the operating mode using PIN diodes. The antenna allows rejecting 5 GHz WLAN and 7 GHz DSS interference by introducing “Γ-T” shape type stubs embedded on the radiating patch. The proposed design has reconfigurable features by using RF PIN diodes switch controlled by embedded module. Analysis of the proposed structure’s performance shows a good agreement between simulated results and actual outcomes measured in real-worlds scenarios. [ABSTRACT FROM AUTHOR]

A miniature multiple input multiple output (MIMO) ultrawide band (UWB) antenna with dual band notched characteristics is proposed. The proposed MIMO UWB antenna has a microstrip feed line, two slotted rectangular radiating structures, and a slotted reduced ground structure. The antenna is constructed on an FR-4 substrate with a 40 × 20 mm2 compact dimension to span the − 10dB bandwidth of 2.5–12 GHz with a fractional bandwidth of 133%. The two notched bands for WiMAX (3.3–3.8 GHz) and WLAN (5–6.5 GHz), respectively, are generated using hook and E-structured stubs etched on patch and defective ground. Over the full operational frequency range, self-isolation of <-15 dB is obtained between two perpendicular radiating patch structures. 4-element MIMO antenna is also designed, studied and analysed. From the determined MIMO parameters, it can be concluded that the recommended antenna is adequate for portable wireless systems. [ABSTRACT FROM AUTHOR]

Wireless networking is encouraged by the constant enhancement of sensors' ability and wireless communication. To provide service quality support for multimedia viz. audio and video streams, the IEEE 802.11e MAC (Media Access Control) improves basic 802.11 MAC. IEEE 802.11 standard series such as IEEE 802.11a, b, g, n, p, and ac have been promoted and specified in the current communications and connection development. Each standard has functionality that matches the kind of applications for which the standard is intended. IEEE 802.11ac has better performance with fewer interferences and achieves gigabits per second capacity transfer rates. This paper discusses the comparative examination of the IEEE 802.11a, IEEE 802.11b, IEEE 802.11 g, IEEE 802.11n, IEEE 802.11p, and IEEE 802.11ac standards which increase accuracy and performance pertaining to the IEEE 802.11 standard. In this paper, we investigate the design requirements for numerous simultaneous peer-to-peer connections. Further, this study offers a systematic review and analysis of the MAC layer in WMN (Wireless Mesh Network) and also highlights their open research issues and challenges. Finally, this paper discusses various potential directions for future research in this area with an emphasis on their strengths and limitations. [ABSTRACT FROM AUTHOR]

This article presents a compact reconfigurable antenna capable of wide-band, dual-band operation. The proposed antenna is having two closed rings with ELC integration in the inner ring. The entire structure is designed and fabricated on a FR4 substrate with the foot print area of 30 × 31 mm2. Initially, a circular ELC-based monopole antenna operating within the frequency range of 2.4 - 2.7 GHz is described. By integrating two p-i-n diodes between the rings and ELC, distinct operating frequency bands are achieved through toggling the diodes. With one diode active, the antenna functions at 2.4 - 2.7 GHz and 4.2 - 4.3 GHz. Activating both diodes extends the bandwidth, enabling operation within the same frequency ranges. The bandwidth of 3200 and 98 MHz is achived in both the bands respectiveley. The gain of the proposed antenna is maintained above 2.0 dBi in the entire operating frequency range. The antenna's compact design, suitable for WiMAX and WLAN applications, is emphasized, and a comparison with contemporary designs underscores its size efficiency and versatile operational modes.

This article proposes a new approach to designing dipole antennas that can create circular polarization. Using a meander-shaped parasitic element in the upper part of the dipole forms a Yagi-Uda-like structure, and the cooperation between the dipole and the parasitic element leads to the production of circular polarization. The main contribution of this work is introducing a new technique for generating circular polarization using dipole antennas. This simple technique leads to a low-profile structure and has provided satisfactory results. Furthermore, by using the introduced CP antenna in a $4\times 4$ array structure and by stimulating a sequentially rotated feeding network, the impedance bandwidth of the antenna is improved, circular polarization with higher purity is achieved, and high radiation gain is achieved. Experimental results approve that the proposed array antenna has an impedance bandwidth of 1.66–3.29 GHz and covers the 1.76–3.12 GHz range with circular polarization. The overall dimension of the proposed array antenna is ( $0.78\times 0.78 \times 0.13$ ) $\lambda ^{3}$ , and a peak gain equal to 11.48 dB was reported for this work.

A novel wireless local area network (WLAN) antenna with dual-polarized and beam-reconfigurable ability is developed for WLAN 2.4 GHz band application. The antenna is composed of a horizontally polarized (HP) antenna and a vertically polarized (VP) antenna. The radiation pattern of the HP antenna can be switched between an omnidirectional beam and four directional beams in the azimuth plane, while the VP antenna can generate an omnidirectional beam and eight directional beams. Then the antenna prototype is fabricated and measured. The directional beam gain of the HP antenna varies from 2.7 to 3 dBi, and that of the VP antenna varies from 2.5 to 3.5 dBi. The maximum difference between the measured and simulated directional beams is 0.9 dBi. The measured and simulated reflection coefficients of the antenna are below −10 dB for all the beam states, and the isolation between the two polarizations is less than −18 dB in the WLAN 2.4 GHz band. The measured results agree well with the simulated ones, showing a good application prospect in WLAN system in the future.

This paper proposes a multi-band coupled-fed antenna (MBCFA) design for 4G LTE, Sub-6G, and WLAN frequencies, suitable for electronic devices with different sizes and fully metallic backplates. The MBCFA structure can be replicated on the fully metallic backplates of laptops, tablets, or smartphones to form a multi-input multi-output (MIMO) antenna system. Each MBCFA at different positions on laptops and tablets exhibits similar resonance characteristics, highlighting its high robustness and stability. The proposed MBCFA is manufactured using low-cost FR4 material. The overall size of MBCFA is 70 mm $\times12.5$ mm and an FR4 thickness of 0.8 mm, the measured reflection losses within the -6dB range are 740–990 MHz (250 MHz bandwidth), 1380–2640 MHz (1260 MHz bandwidth), and 4250–7330 MHz (3080 MHz bandwidth). The MBCFA’s isolation levels in the 4G LTE frequency band are below -16 dB, while the remaining frequency bands have isolation levels below -20 dB. The maximum antenna gain is approximately 5 dBi, and the optimal antenna efficiency is 60%. The Equivalent Coupling Coefficient (ECC) for all frequency bands is below 0.5. Given the excellent antenna characteristics described above, the proposed multi-band coupled-fed antenna is an outstanding candidate for laptop, tablet, and smartphone antennas.

In this article, the design and analysis of a compact octa‐band antenna employing the PIN diode to realize frequency reconfigurable characteristics is presented. The presented antenna is backed by a partial ground plane and printed on top of a 1.53 mm thicker FR4 substrate. The antenna size is very compact (25 mm × 14 mm × 1.53 mm), and can be readily incorporated with many other RF front‐end circuits. The presented antenna consists of a semi‐heptagonal, semi‐hexagonal, inverted L‐shaped, and inverted Z‐shaped monopoles. Depending on the position of the lumped element switch, the presented antenna can operate in eight different frequency modes. The investigated antenna realizes Penta/Triple band characteristics by turning ON/OFF the PIN diode positioned between the inverted L‐shaped monopole and feedline. While in ON state, the investigated antenna covers five unique frequencies 1.82 GHz (DCS/5G NR n70), 2.43 GHz (Bluetooth/RFID), 3.75 GHz (LTE 42–43/5G NR n77/Wi‐MAX), 5.4 GHz (U‐NII‐2A & ‐2B), and 5.84 GHz (U‐NII‐3 & V2X) and in OFF state, the antenna covers three unique frequencies 1.95 GHz (PCS/UMTS/LTE 34–37), 2.59 GHz (LTE 2500 & WLAN 2.4 GHz), 4.71 GHz (5G NR n79 & WLAN 5GHz) for wireless applications. The investigated antenna exhibits excellent impedance bandwidths of 1.69–1.9 GHz (BW = 11.6%), 1.8–2.1 GHz (BW = 15.4%), 2.37–2.56 GHz (BW = 7.7%), 2.4–2.7 GHz (BW = 11.8%), 3.49–4.2 GHz (BW = 18.4%), 4.3–5.55 GHz (BW = 25.4%), 5.2–5.52 GHz (BW = 6%), and 5.78–5.9 GHz (BW = 5.5%) at 1.82/1.95/2.43/2.59/3.75/4.71/5.4, and 5.84 GHz, respectively. The measurements demonstrate that the designed antenna has omnidirectional radiation characteristics with 1.15–4.4 dBi gain. The proposed design's simulated and measured results are compared, and show good agreement. [ABSTRACT FROM AUTHOR]

This article demonstrates a portable ultrawideband (UWB) diversity antenna with capability of rejecting WLAN band. A circular split ring resonator (SRR) slot is etched out in the patch for filtering out the interference due to WLAN band centered at 5.2 GHz. A partial common ground plane with T-shaped stub is employed for high isolation. A fair correlation is reported between the simulated and experimentally measured findings with |S11| < −10 dB in the operational band. The measured isolation of |S21| < −20 dB along with satisfactory diversity performance metrics prove the utility of suggested antenna for UWB MIMO applications. [ABSTRACT FROM AUTHOR]

This paper presents a field-programmable gate array (FPGA) implementation of IEEE wireless local area network (WLAN) medium access control (MAC) system with high-throughput performance. For an efficient and optimal design procedure, we analyzed the throughput bottlenecks of the previously implemented architecture of WLAN MAC, and verified the throughput enhancement using SystemC based transaction-level model (TLM) simulation. Also, by using hardware-software partitioning scheme and transmit queue, the legacy MAC architecture is enhanced. At the physical layer (PHY) rate of 600Mbps, the proposed architecture, compared with the legacy MAC architecture, exhibits 4x and 4.35x MAC efficiency for voice and video access categories, respectively. The implemented results show that the video access category packet could be transmitted with the MAC throughput of 450Mbps, given the PHY rate of 600Mbps, achieving the MAC efficiency of 75%. Also the resource usage of the proposed system architecture is about 14% utilization on the Xilinx Virtex5LX330 FPGA prototyping board. [ABSTRACT FROM AUTHOR]

This paper will propose an innovative compact, lowcost, low-profile inverted U-shaped patch antenna with a single and dual band-notched ultra-wideband (UWB) with split ring resonators (SRRs). To achieve our main goal based on the reduction of electromagnetic interference in narrowband communications (WLAN, WiMAX, and satellite), four-element rectangular split-ring resonators (SRRs) array are placed nearby the feedline to create notch band at approximately 5.15-5.35 and 5.725-5.85 GHz. The SRRs antenna's measured data indicate a directivity of 8.52 dBi, a gain of 7.18 dBi, a reflection coefficient of -27 dB, and an efficiency of 84.3%. The realized prototype, including the SRRs and CSRRs structures, were carried out using a PCB prototyping machine. Reflection coefficient measurement is obtained using a vector network analyzer (VNA) PNA-X from Agilent Technologies. The measured values of the proposed antenna, with 50 x 38 x 1.6 mm3 in total and constructed on a FR4 substrate with permittivity of er = 4.3, loss tand = 0.0024 and substrate thickness of h = 1.6 mm, correlate well with the simulated values. The proposed antenna, compared with other published work, is a good candidate to operate in WLAN, X-band. [ABSTRACT FROM AUTHOR]

Wireless Local Area Network (WLAN) technology has advanced recently as a result of the proliferation of wireless strategies and the rising demand for speed data transfer. A dual-band microstrip patch antenna with a Split-Ring Resonator (SRR)and defective ground plane is proposed that resonates at 5.3 GHz, so it can be used for WLAN and WiMAX applications. The antenna uses a Polyimide substrate to achieve flexibility with a 0.25mm thickness, thus providing conformal mounting. The simulated reflection coefficient is about -15 dB, and the VSWR is 1.4. The measured reflection coefficient is 30 dB. The maximum gain obtained is 2.749 dBi. Compared with the existing antennas, the proposed antenna can be bent and fit within the available space. [ABSTRACT FROM AUTHOR]

A compact horn-slotted coplanar waveguide (CPW) fed dual-band dual-sense circular polarization antenna is proposed. The antenna resonates with right-handed circular polarization in the lower frequency band and left-handed circular polarization in the upper frequency band. It has a novel horn-shaped slot and a CPW-fed inverted L-shaped active patch. The inverted L-shaped patch with a slanted stub at its right side provides dual-band dual-sense circular polarization characteristics. It has a compact geometry of 0.27 λ0 × 0.27 λ0 × 0.017 λ0, with wideband circular polarization characteristics extending from 2.92 to 3.67 GHz (22.82% of ARBW) and 5.2–5.73 GHz (9.5% of ARBW), thereby covering 5G and WLAN applications, respectively. [ABSTRACT FROM AUTHOR]

The role of antennas in wireless communication is critical for enabling efficient signal transmission and reception across various frequency bands, including those associated with IoT (Internet of Things), X-band, S-band, and RFID (radio-frequency identification) systems. This paper presents a small quadruple-band antenna with 25 × 40 × 1.5 mm3 dimensions designed for diverse wireless applications. It is adept at operating in the S-band (2.2 GHz), wireless local area network (WLAN) (5.7 GHz), microwave RFID frequency band (5.8 GHz), and X-band (7.7 GHz and 8.3 GHz). While the majority of existing research focuses on antennas covering two or three bands, our work stands out by achieving quad-band operation in the proposed antenna design. This antenna is constructed on a semiflexible Rogers RT5880 substrate, making it well-suited for wearable applications. Computer Simulation Technology (CST) Microwave studio (2019) simulation package software is chosen for design and analysis. The antenna design features a comb-shaped radiating structure, where each "tooth" is responsible for resonating at a distinct frequency with an appropriate bandwidth. The antenna retains stability in both free space and on-body wearability scenarios. It achieves a low specific absorption rate (SAR), meeting wearable criteria with SAR values below 1.6 W/Kg for all resonating frequencies. The proposed antenna demonstrates suitable radiation efficiency, reaching a maximum of 82.6% and a peak gain of 6.3 dBi. It exhibits a bidirectional pattern in the elevation plane and omnidirectional behavior in the azimuth plane. The antenna finds applications across multiple frequencies and shows close agreement between simulated and measured results, validating its effectiveness. [ABSTRACT FROM AUTHOR]

In this paper, a portable tri-band MIMO antenna with 1 × 1 and 2 × 2 inputs and outputs is developed for wireless applications. A decagon-shaped ring and two U-shaped radiating structures make up the proposed antenna, which can generate three resonance frequencies. Without utilizing any decoupling structures, the suggested antenna achieves improved isolation. The coplanar waveguide structure supplies all of the antennas, which are printed on the front side of the FR-4 substrate, which has a surface area of 18 × 18 mm. The suggested antenna serves a wide range of applications, including WLAN (5.2 GHz), Wi-max (5.5 GHz), and 5G n34 band, with an impedance bandwidth of − 10 dB over 1.98–2.03 GHz, 3.55–3.70 GHz, and 4.8–6.4 GHz (2 GHz). For tri-band MIMO antenna, the gain is (0.28 dB, 1.3 dB and 2.7 dB) and efficiency is (80%, 83%, and 91.5%). For MIMO, tri-band antennas are placed in rotational symmetry with respect to the adjacent ports. Distance between MIMO tri-band antenna is 20 mm. Isolation for tri-band MIMO antennas is (− 40 dB, − 28.5 dB and − 27 dB). ECC for tri-band MIMO antenna is 0.003. The fabricated antenna and simulated results agree quite well. As a result, the suggested antenna can be employed for WLAN and 5G applications. [ABSTRACT FROM AUTHOR]