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Conventionally, both electrically larger (EL) arrays and sparse arrays offer the advantage of element number reduction but disadvantage of high sidelobe levels. A new scheme of planar EL sparse array antenna based on a genetic algorithm (GA) to achieve low sidelobe with element number reduction is proposed. To begin with, EL sparse array antenna optimisation models based on GA for both linear and planar arrays are analysed. Then, an EL slot antenna element based on a 3 × 3 substrate integrated waveguide cavity is designed. An 8‐element linear EL sparse array antenna is designed and compared with a uniform array antenna, demonstrating a reduction in the maximum sidelobe level (MSLL) by nearly 4.6 dB. After that, a 4 × 8 element planar EL sparse array antenna is fabricated and measured. Compared to an 8 × 16 element planar EL uniform array antenna, the number of antenna elements is reduced by 75%, while the MSLL is reduced by approximately 3 dB. The measured −10 dB impedance bandwidth ranges from 25.3 to 27.8 GHz. At the central frequency, the radiation pattern achieves a peak gain of 29.6 dBi, exhibiting low sidelobe levels below −15.0 dB. [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]

A novel compact dual-band antenna based on dual-cap metasurface (MS) is proposed. By etching circumferential circular ring slots on one side of the substrate and a large cruciform slot on the other side, the dual-cap MS operates in two frequency bands. In addition, by placing the dual-cap MS at the back of a circular ring planar antenna which serves as a reflector, the impedance characteristic of the antenna in lower band and gain both in two bands are improved. The results show that this dual-cap MS antenna operates in the Wireless Local Area Network (WLAN) bands of 2.43-2.6 GHz and 5.48-6.05 GHz. Moreover, the maximum gains in lower and upper bands can reach 6.9 and 5.8 dBi, respectively. [ABSTRACT FROM AUTHOR]

The integration of the 60 GHz band into the IEEE 802.11 standard has revolutionized indoor wireless services. However, this band presents unique challenges to indoor wireless communication infrastructure, originally designed to handle data traffic in residential and office environments. Estimating 60 GHz signal propagation in indoor settings is particularly complicated due to dynamic contextual factors, making it essential to ensure adequate coverage for all connected devices. Consequently, empirical channel modeling plays a pivotal role in understanding real-world behavior, which is characterized by a complex interplay of stationary and mobile elements. Given the highly directional nature of 60 GHz propagation, this study addresses a seemingly simple but important question: what is the impact of employing highly directive antennas when deviating from the line of sight? To address this question, we conducted an empirical measurement campaign of wireless channels within an office environment. Our assessment focused on power losses and distribution within an angular range while an indoor base station served indoor users, simulating the operation of an IEEE 802.11ad high-speed WLAN at 60 GHz. Additionally, we explored scenarios with and without pedestrian movement in the vicinity of wireless terminals. Our observations reveal the presence of significant antenna lobes even in obstructed links, indicating potential opportunities to use angular combiners or beamformers to enhance link availability and the data rate. This empirical study provides valuable information and channel parameters to simulate 60 GHz millimeter wave (mm-wave) links in indoor environments, paving the way for more efficient and robust wireless communication systems. [ABSTRACT FROM AUTHOR]

This paper introduces a square slot antenna with circular polarization and dual-band capability. The structure of the antenna is similar to an L-shape patch but with modifications in the lower rectangular part of the L, the patch has been transformed into a circle. Additionally, two strips having rectangular shape are located on the ground plane at opposite corners. By adjusting the size of the rectangular strips, the antenna can achieve dual-band and dual-sense circular polarization. The measured results of this design indicate that the Impedance Bandwidths are 45.16% (2.4–3.8 GHz) and 43.75% (5–7.8 GHz), while the Axial Ratio Bandwidths are 45.16% (2.4–3.8 GHz) and 37.4% (5–7.3 GHz) for the lower and upper bands respectively. [ABSTRACT FROM AUTHOR]

This paper presents the design of a performance-improved 4-port multiple-input–multiple-output (MIMO) antenna proposed for millimeter-wave applications, especially for short-range communication systems. The antenna exhibits compact size, simplified geometry, and low profile along with wide bandwidth, high gain, low coupling, and a low Envelope Correlation Coefficient (ECC). Initially, a single-element antenna was designed by the integration of rectangular and circular patch antennas with slots. The antenna is superimposed on a Roger RT/Duroid 6002 with total dimensions of 17 × 12 × 1.52 mm3. Afterward, a MIMO configuration is formed along with a novel decoupling structure comprising a parasitic patch and a Defected Ground Structure (DGS). The parasitic patch is made up of strip lines with a rectangular box in the center, which is filled with circular rings. On the other side, the DGS is made by a combination of etched slots, resulting in separate ground areas behind each MIMO element. The proposed structure not only reduces coupling from −17.25 to −44 dB but also improves gain from 9.25 to 11.9 dBi while improving the bandwidth from 26.5–30.5 GHz to 25.5–30.5 GHz. Moreover, the MIMO antenna offers good performance while offering strong MIMO performance parameters, including ECC, diversity gain (DG), channel capacity loss (CCL), and mean effective gain (MEG). Furthermore, a state-of-the-art comparison is provided that results in the overperforming results of the proposed antenna system as compared to already published work. The antenna prototype is also fabricated and tested to verify software-generated results obtained from the electromagnetic (EM) tool HFSS. [ABSTRACT FROM AUTHOR]

This paper presents, a monopole rectangular patch antenna (0.57 × 0.52 × 0.035 λ3) featuring two horizontal slots and vertical rectangular slits, designed for single-band application. The analysis focuses on its suitability for single-band wireless communication applications. The proposed antenna resonates at frequency of 6.6 GHz and has a bandwidth of 500 MHz (from 6.38 to 6.88 GHz). The simulated results, including reflection coefficient, radiation pattern, gain, and surface current distribution, are presented in this paper. At the operating frequency of 6.6 GHz, the antenna achieves a gain of 3.24 dBi and a reflection coefficient of − 32.2 dB. The simulated and measured results of the proposed antenna are in good agreement, demonstrating its suitability for wireless communication applications. [ABSTRACT FROM AUTHOR]

This study focuses on improving data rates in wireless networks through the design, simulation and measurement of a frequency reconfigurable four port MIMO antenna. The antenna is specifically developed for Wi-Fi, wireless local area network, and Industrial, scientific and medical applications. The antenna design has microstrip patch components, a closely built decoupling structure, an electromagnetic band gap structure, and a defective ground structure. These features enhance the antenna's MIMO performance at specific frequencies of operation and minimize radiation losses. The antenna design includes an RF PIN diode to allow for reconfigurability. This enables the antenna to operate at resonating frequencies between 2.39 and 5.36 GHz while the diode is in the ON and OFF states, respectively. The MIMO antenna under consideration is assessed on a FR4 substrate of 70 × 65.5 mm 2 and the wavelength is 0.56 × 0.53 λ 0 . It achieves a peak gain of 7.3 dBi at 2.39 GHz and 8.2 dBi at 5.36 GHz. The simulated results are implemented using HFSS and measured using network analyser KEYSIGHT N9951A. The bandwidths achieved are 0.07 at 2.39 GHz and 0.53 at 5.36 GHz. The experimental results on analysing various antenna characteristics are observed as Total active reflection coefficient value less than 0 dB, envelope correlation coefficient less than 0.5, Mean effective gain value less than − 3 dB, etc. The gain of the proposed four port reconfigurable MIMO antenna is 10% improvement when compared with existing works. The results from the simulated and measured matches well within the two operating bands, indicating that the suggested topology could be used for 5G communications. [ABSTRACT FROM AUTHOR]

Reflectarray (RA) antennas are gaining recognition as a high‐performance alternative for antenna design. They combine the functionalities of standard parabolic reflectors and phased array antennas without a feed network. However, the design of RA models requires a model that exhibits exceptional performance while meeting contradictory requirements such as size and operation band. An effective and computationally efficient approach is to employ a rapid and precise unit element model for the design of reflective antennas. Artificial intelligence (AI) regression techniques have been developed to predict electromagnetic behavior efficiently and accurately in microwave device design. A cross‐shaped 3D printable RA was examined as a case study, and a design‐ready surrogate model was developed with a mean absolute error of approximately 5° using only 800 data samples. The method can be considered a feasible substitute for current surrogate‐assisted RA design techniques due to its computational efficacy and dependability. [ABSTRACT FROM AUTHOR]

This paper presents the design, development, and testing of a novel cavity backed self diplexing antenna using Substrate Integrated Waveguide (SIW) method with a plus shape, that provides self-diplexing functionality for dual-frequency communication applications. The antenna structure is designed using computer-aided design (CAD) software tool - HFSS and optimized for high performance characteristics, including gain, directivity, and radiation efficiency, at frequencies of 5.5 GHz and 6.2 GHz. The antenna's performance is simulated using a simulation software tool, and the fabricated antenna is tested using Vector Network Analyzer. The results demonstrate that the cavity backed self diplexing antenna using Substrate Integrated Waveguide (SIW) method with a Slot of plus shape provides high performance characteristics and self-diplexing functionality for dual-frequency communication applications. The antenna's performance is evaluated based on the design specifications and requirements, and compared with other existing antenna designs to demonstrate its superiority. The proposed antenna structure offers significant potential for dual-frequency communication applications in various fields, including radar, and satellite communication. [ABSTRACT FROM AUTHOR]

The rising popularity of Voice over WiFi (VoWiFi) needs a dedicated effort to find new solutions to expand VoWiFi cell capacity. The main aim of this research is to enhance the VoWiFi cell capacity using aggregate MAC protocol data unit (A-MPDU) frame aggregation. In this regard, we developed a mathematical formula to estimate the number of VoWiFi users that can be allowed without compromising the quality-of-service (QoS) of existing VoWiFi calls over the Wireless Fidelity (WiFi) standards by considering Arbitration inter-frame spacing (AIFS), Compressed RTP (cRTP) and A-MPDU frame aggregation. In this work, we utilized AIFS to assess the channel state prior to transmit VoWiFi data from the sender user equipment (UE) to the receiver UE and Short Inter-frame Spacing (SIFS) to transmit Request To Send (RTS) / Clear To Send (CTS) and Acknowledgement (ACK) frames. Using our proposed model, we have examined VoWiFi cell capacity considering A-MPDU frame aggregation in constant bit rate (CBR) traffic using AIFS and DCF Inter-frame Spacing (DIFS) in IEEE 802.11b/g/n/ac/ax/be Wireless Local Area Network (WLAN) standards. Additionally, we have found the maximum number of MAC protocol data unit (MPDU)s aggregated in a single A-MPDU for IEEE 802.11b/g/n/ac/ax/be. Further, we have analyzed the effect of voice packet retransmission on the cell capacity of a WLAN standard that provides VoWiFi service considering A-MPDU technique. [ABSTRACT FROM AUTHOR]

There has been a lot of interest in microstrip diplexers lately due to their potential use in numerous wireless and computer communication technologies, including radio broadcasts, mobile phones, broadband wireless, and satellite-based communication systems. It can do this because it has a communication channel that can combine two distinct filters into one. This article presents a narrow-band microstrip diplexer that uses a stepped impedance resonator, a uniform impedance resonator, tiny square patches, and a meander line resonator. The projected diplexer might be made smaller than its initial dimensions by utilizing the winding construction. To model the microstrip diplexer topology for WiMAX and WIFI/WLAN at 1.66 GHz and 2.52 GHz, the Advanced Wave Research (AWR) solver was employed. It exhibited an insertion loss of 3.2 dB and a return loss of 16 dB for the first channel, while the insertion loss and return loss were 2.88 dB and 21 dB, respectively, for the second channel. When both filters were simulated, the band isolation was 31 dB. The projected microstrip diplexer has been fabricated using an FR4 epoxy laminate with dimensions of 32 × 26 mm2. The simulated S-parameters phase and group delay closely matched the measurements. [ABSTRACT FROM AUTHOR]

The study presents an innovative approach to designing a Circular Microstrip Patch Antenna capable of covering a broad range of frequency bands. The physical measurements of the antenna are 34x22 x 1.57 mm³. Rogers RT5880 (Lossy) substrate has been chosen to build the antenna, which has a dielectric constant (εr) of 2.2. The antenna's radiating patch layer and the ground plane layer has been structured from copper, each with a thikness of 0.035 mm. The resonance at five distinct frequencies: 5.2 GHz, 6.628 GHz, 9.098 GHz, 12.036 GHz, and 13.076 GHz is the key element of this antenna. These frequencies cover a broad range of applications including WLAN, C-band, X-band, and Ku-band. Simulations has been applied using the CST Software version 2021 to validate the antenna performance. The adaptability of the antenna design, coupled with its successful validation, makes it suitable for a broad range of wireless applications across different frequency bands. This highlights their effect and applicability across a variety of technological fields. [ABSTRACT FROM AUTHOR]

In this article, an ultra-wideband (UWB) antenna featuring two reconfigurable quasi-perfect stop bands at WLAN (5.25–5.75 GHz) and lower 5G (3.4–3.8 GHz) utilizing electromagnetic bandgaps (EBGs) and positive-intrinsic-negative (P-I-N) diodes is proposed. A pair of EBG structures are applied to generate sharp notch bands in the targeted frequency spectrum. Each EBG creates a traditional notch, while two regular notches are combined to make a quasi-perfect, sharp, notch band. Four P-I-N diodes are engraved into the EBG structures to enable notch band reconfigurability. By switching the operational condition of the four diodes, the UWB antenna can dynamically adjust its notching characteristics to enhance its adaptability to various communication standards and applications. The antenna can be reconfigured as a UWB (3–11.6 GHz) without any notch band, a UWB with a single sharp notch (either at WLAN or 5G), or a UWB with two quasi-perfect notch bands. Moreover, the antenna's notch bands can also be switched from a traditional notch to a quasi-perfect notch and vice versa. To confirm the validity of the simulated outcomes, the proposed reconfigurable UWB antenna is fabricated and measured. The experimental findings are aligned closely with simulation results, and the antenna offers notch band reconfigurability. The antenna shows a consistently favorable radiation pattern and gain. The dimension of the presented antenna is 20 × 27 × 1.52 mm3 (0.45 λc × 0.33 λc × 0.025 λc, where λc is the wavelength in free space). [ABSTRACT FROM AUTHOR]

This paper presents a dual-band 8-port multiple-input multiple-output (MIMO) antenna specifically designed for fifth-generation (5G) smartphones, featuring two open-slot metal frames. To enhance impedance matching and improve isolation between adjacent antenna elements, each antenna element employed a coupling feed. All simulation results in this paper come from Ansys HFSS. The operational frequency bands of the proposed antenna spanned 3.36–4.2 GHz for the lower band and 4.37–5.95 GHz for the higher band, covering 5G New Radio (NR) bands N78 (3.4–3.6 GHz) and N79 (4.4–4.9 GHz), as well as WiFi 5 (5.15–5.85 GHz). Notably, the antenna demonstrated outstanding isolation exceeding 16.5 dB within the specified operating bands. The exceptional performance positions the proposed antenna as a promising candidate for integration into 5G metal-frame smartphones. [ABSTRACT FROM AUTHOR]

Nowadays multiband antennas are preferred in wireless communication. Emerging technologies demand compact multiband antennas to support different frequency ranges required for diverse applications. This paper outlines the design of quadband antenna mainly for the UWB frequency range. Accordingly, two compact microstrip structures namely Phi Shape Dual Square ring (PSDSR) and Phi Shape Dual Circular ring (PSDCR) are proposed. The concept begins with designing a primary antenna that involves merging of monopole antenna with the PSDSR structure. The designed dimensions of PSDSR viz. ring perimeter, gap and width are applied directly to the PSDCR antenna without any variation. Anysis HFSS has been used to evaluate the performance of proposed antennas in terms of VSWR, return loss, gain, radiation pattern, and surface current. Simulation results reveal that the two antennas have remarkably similar responses in four different frequency bands. The proposed antennas are fabricated on FR4 substrate and have dimensions of 72x23x1.6mm. It is found that measured and simulated results are in close resemblance with each other. The VSWR values are obtained between 1 and 2 which indicate that these antennas have good impedance matching with the feed line. The designed antennas find variety of applications in technologies such as WiFi, WiMAX, WLAN and 5G wireless systems. [ABSTRACT FROM AUTHOR]

Purpose: Limited availability of life cycle assessment (LCA) data poses a significant challenge to its mainstream adoption, rendering it a central issue within the LCA community. The Global LCA Data Access (GLAD) network aims to increase the accessibility and interoperability of LCA data and offers benefits for different use cases. GLAD is an intergovernmental collaboration involving different stakeholders organized into working groups. The GLAD Nomenclature Working Group (NWG) developed a procedure and a set of criteria to map elementary flows among major nomenclature systems and reviewed bidirectional mappings. This paper provides an overview of the methodological approach followed by the NWG to achieve the resulting mapping files. Methods: The mapping procedure involves several steps of flow and compartment matches and bilateral review. The procedure is supported by an ad hoc software tool called the "GLAD Mapper Tool" developed with the NWG and which is made available for free by the European Commission. The input files for the procedure are the properly formatted source and target flow lists and a file containing the mapping criteria. The four nomenclature systems mapped are those used in ecoinvent, Environmental Footprint, IDEA, and the U.S. Federal LCA Commons. The procedure included representatives from each of these nomenclature systems to ensure a multilateral agreement on the approach to verifying and assessing the quality of the results. The iterative mapping process included different stages of bidirectional reviews to achieve a balance between mapping coverage (i.e., percentage of source flows covered by the target list) and accuracy. Results and discussion: The mapping procedure proved to be an efficient approach for LCA practitioners in mappings between different nomenclature systems. After a relatively low number of iterations, mapping coverages higher than 90% were achieved, which is driven by the availability of unique substances (flow names) and the granularity of environmental compartments. Overall, none of the four flow lists achieved full coverage and the use of approximated matches (proxy matches) for environmental compartments and/or substances was necessary when a perfect matches between flows were not possible. Conclusions: The NWG's mapping activities may serve as a starting point towards defining a central hub for mapping impact assessment methods and datasets, improving data accessibility and interoperability for the LCA community as a step towards defining a unified nomenclature system. The GLAD mapping approach is open and transparent. The approach fosters traceability in the mapping process and offers the potential for greater interoperability across the LCA community, underlining the commitment to openness and collaboration. [ABSTRACT FROM AUTHOR]

A new tri-band rectangular DRA is simulated and tested for wireless communication applications like ISM, Wi-Max, and WLAN. The dielectric resonator antenna structure is excited by a 50Ω transmission line. The rectangular DRA with concentric square rings is designed to acquire the operation of triple-bands. The investigated antenna parametric study has been accomplished on HFSS tool. The implemented design exhibits triple-band characteristics at 2.16-2.57 GHz, 3.35-4.45 GHz, and 5.35-5.95 GHz, with a fractional bandwidth of 17.3%, 28.1%, and 10.6%, respectively. The implemented concentric square rings are imposed on FR4-substrate material to emphasize the antenna parameters and to minimize the size. The designed antenna has a compact size, good radiation properties, and optimal operational bandwidth. To validate the antenna, it is fabricated, and the results match well with the simulated ones. The antenna is well suitable for wireless communication applications. The fabricated rectangular DRA is measured by using MS2037C Anritsu-Combinational Analyzer. [ABSTRACT FROM AUTHOR]

A design of a compact planar SIW filter with notch band characteristics is proposed. Double split square complementary split ring resonators are used to realize the ultra-wideband (UWB) characteristics. Proposed UWB filter contributes a passband from 2.9 GHz to 10.3 GHz with minimum insertion loss 0.7 dB at 3.7 GHz and maximum of 1.84 dB at 7 GHz. By employing a complementary split ring resonator in the ground plane, a narrow band characteristic is obtained to reject the undesired wireless local area network (WLAN) signals. The notch band frequency ranges from 5 GHz to 5.7 GHz with insertion loss of 14 dB at center frequency. The 3 dB fractional bandwidth in the notch band is 12.9%. The variation of group delay is less than 0.5 ns in the passband range. Overall size of the proposed filter is 0.35λg x 1.06λg. Because of these salient features, the proposed filter can be used for space applications. [ABSTRACT FROM AUTHOR]

For applications involving triple bands, a small slot structure loaded with an asymmetric split ring resonator (ASRR) is suggested in this article. The slot mode, which is agitated with the help of a microstrip line feed, produces the first band. 2.24 GHz resonance frequency is the intended operating band. The second and third frequency bands are achieved by loading ASRR on the slot. The slot produces axial magnetic field required to excite the ASRR. The asymmetry introduced in the conventional SRR produces dual resonances. The ASRR gives the resonant frequencies at 2.97 GHz and 3.66 GHz. The frequency bands of the slot and ASRR can be independently tuned. The proposed geometry is verified experimentally, and it is in good agreement with the simulated one. The impedance bandwidth of all three resonant bands measured from experiment are 14.25%, 1.78%, 8.37%. The peak gains of 3.1 dBi, 2.18 dBi, and 3.29 dBi are obtained at resonant points, respectively. The designed antenna is compact and well suits for wireless application like WLAN, GPS, and LTE48/TD3600. [ABSTRACT FROM AUTHOR]

This article proposes a versatile Multiple Input Multiple Output (MIMO) antenna designed for contemporary wireless systems spanning frequencies from 3 to 20 GHz. It serves applications such as 5G mobile, WiFi, WiFi-6E, X-band, partial Ku, and K-band. The original single-element antenna evolves into a 4 × 4 MIMO configuration with optimized ground plane modifications for enhanced performance. A decoupling structure achieves over 20 dB isolation between inter-elements. The feeding structure, featuring a gradually changing design connected to the antenna's radiating structure, achieves wide bandwidth characteristics. This is further improved by a partial ground structure and slots on the radiating element. The lower frequency band of 3 to 7 GHz is attained with a rectangle-shaped radiator, while semi-circular microstrip lines atop the radiator enable the higher frequency bands of 8 to 15.4 and 18.7 to 20 GHz. The slots and ground structure enhance impedance bandwidth, and semicircles improve the radiation pattern. The MIMO antenna demonstrates measured peak gains of 6.23 dBi at 11.5 GHz, maintaining a radiation efficiency exceeding 80%. Validation through metrics like ECC, DG, CCL, and TARC confirms strong agreement between simulated and experimental results, positioning the MIMO antenna as a robust choice for various wireless communication applications. [ABSTRACT FROM AUTHOR]

In this paper, a high gain antenna using Frequency Selective Surface (FSS) is proposed. The compact structure is designed from a circular Ultra-wideband (UWB) monopole. Higher order modes of UWB antenna are suppressed by decreasing the thickness of the monopole, ground plane dimensions, and increasing the gap between the ground plane and the monopole. Symmetrical portion of circular monopole is etched to form a semicircular monopole, and an off-set feed is employed. Dual band characteristics and miniaturization are achieved by etching horizontal and vertical slots and reducing ground plane dimensions. An FSS reflector is designed for gain enhancement. This miniaturized antenna offers less blockage and therefore, higher gain improvement when an FSS is used as a reflector. [ABSTRACT FROM AUTHOR]

This paper presents folded cascode Low Noise Amplifier (LNA) designed for Wireless Local Area Network (WLAN) applications. The proposed LNA uses complementary current reuse technique and diode connected forward body biasing technique to lower the power consumption and boost the transconductance for gain enhancement. Moreover, post linearization is done by P-MOS (Metal Oxide Semiconductor) Inter Modulation Distortion (IMD) sinker which reduces inter modulation distortion present at the input and achieves better linearity of the LNA. Under cadence virtuoso environment, using 180 nm Complementary Metal Oxide Semiconductor (CMOS) technology, the designed LNA exhibit high gain (S21) of 25.4 dB followed by noise figure of 1.75 dB at a reduced supply voltage of 0.6 V. The other important parameters including reflection coefficient (S11) − 12 dB, power dissipation (Pdc) 3.23 mW and Third order Input Intercept Point (IIP3) − 4.43 dBm are also achieved. This demonstrates the applicability of proposed LNA for wireless applications functioning in 5.2 GHz. [ABSTRACT FROM AUTHOR]

The dedicated network of the Jiangsu Provincial Department of Ecology and Environment is in need of upgrades and transformation. A project team was established to conduct extensive research and analysis on technical systems. After a lot of technical system demonstration and research work, it was decided that the upgrade and transformation should be based on software-defined wide area network (SDWAN) technology. An overview of the current state of the dedicated network was proposed, a needs analysis was conducted, and a technical solution was proposed to meet the requirements of the upgrade. The proposed solution includes overall solution design, SDWAN solution design, security protection design, and network management design. [ABSTRACT FROM AUTHOR]

An electrically small multiband planar antenna is presented by using rectangular split ring resonator (RSRR) metamaterial element for LTE, WiMAX and WLAN applications. The designed antenna possesses asymmetric coplanar strip (ACS)-fed Hilbert Curve Fractal Antenna (HCFA) loaded with RSRR metamaterial for multiband radiation at 1.44 GHz, 3.76 GHz and 5.27 GHz. ACS-fed HCFA is responsible for creating the first (at 1.44 GHz) and second (at 3.76 GHz) resonance frequencies owing to the coupling between ACS-fed HCFA and ground plane. Moreover, the RSRR yields upper resonance at 5.27 GHz owing to the metamaterial transmission line. The stop band and pass band nature of the RSRR and its negative permeability characteristics are described using an effective medium theory. An equivalent circuit model of the proposed antenna is investigated with the help of Agilent ADS to validate the operating frequencies. Also, the geometrical parameters have been optimized using the artificial neural network (ANN), which is performed by MATLAB. The proposed antenna has been fabricated on a 18 × 16.5 × 1.6 mm3 FR-4 dielectric having ε r = 4.4 and tan δ = 0.02. It provides multiband response at 1.4 GHz, 4.4 GHz and 5.3 GHz with a − 10 dB impedance bandwidth of 330 MHz, 570 MHz, and 340 MHz, respectively, which is usable for LTE, WiMAX and WLAN band applications. [ABSTRACT FROM AUTHOR]

In this study, we designed a wideband CMOS power amplifier to support multi-band and multi-standard wireless communications. First, an input matching technique through LC network and a wideband design technique using a low Q-factor transformer were proposed. In addition, a design technique was proposed to improve output matching using RC feedback. To verify the feasibility of the proposed design methodology for wideband CMOS power amplifiers, the designed power amplifier was fabricated using a 180 nm RFCMOS process. The size including all of the matching network and test pads was 1.38 × 0.90 mm2. In addition, the effectiveness of the proposed power amplifier was verified through the measured results using modulated signals of WCDMA, LTE, and 802.11n WLAN. [ABSTRACT FROM AUTHOR]

In the present work, a metamaterial-inspired high gain multiband Circular Microstrip Antenna (CMSA) that facilitates operation at 2.4 , 3 , 5 , 7.1 , 8.45 , and 9.9 GHz for wireless communication is designed and illustrated. The antenna configuration consists of an array of crossed Complementary symmetry Split Ring Resonators (CSRR) as a metamaterial structure in the radiating patch that facilitates multiband operation and the meshed ground plane that facilitates high gain and bandwidth operations. A low-cost FR4 epoxy substrate with a thickness of 1.6 mm is used to fabricate the antenna. The overall structure is analyzed and validated using HFSS (High Frequency Structure Simulator). The simulated and measured results of the proposed antenna structure are in good agreement. The antenna attains a measured − 10 dB S 11 bandwidth 210 MHz with an improved gain of 3.48 dB and overall 90 % radiation efficiency at the desired resonating frequency of 2.45 GHz . The designed antenna offers appealing characteristics in the Industry Scientific and Medical (ISM) band and wireless communication applications for other operational bands like WLAN and Wi-MAX. [ABSTRACT FROM AUTHOR]

In this work, a dual-band dual circularly polarized coplanar waveguide (CPW)-fed monopole antenna is presented. The antenna consists of the modified ground plane, and two rectangular-shaped radiators, which are located on the two sides of the monopole. The radiating patches are loaded with metamaterial dependent electromagnetic band-gap structures for obtaining wider impedance bandwidth and broad axial ratio characteristics. The proposed antenna features impedance bandwidth of 97.4% (1–2.9 GHz) in the first band and 61.36% (3.05–5.75 GHz) in the second band, covering applications of ISM-band (2.4–2.48 GHz), Wi-MAX (2.5–2.69 GHz, 3.4–3.69 GHz), and WLAN (2.4–2.48 GHz, 5.15–5.35 GHz). The antenna also features dual circular polarization with 3-dB axial ratio bandwidth of 33.8% (1.35–1.9 GHz) and 35.7% (3.1–4.45 GHz), in the first and second bands, respectively. The first band shows right-hand circular polarization, whereas the second band exhibits left-hand circular polarization. [ABSTRACT FROM AUTHOR]

In this paper, a co-aperture dual-polarized antenna array is proposed. The frequency band covers the P-band (0.4–0.7 GHz) and the X-band (9.3–9.9 GHz). The P-band array is designed in the form of an all-metal Vivaldi, while minimizing the impact of the P-band antenna array structure on the X-band electrical performance. The final profile design for the dual-band antenna structure is only 0.12 λ0 (λ0 corresponds to the wavelength of 0.4 GHz). The X-band design adopts the miniaturized waveguide slot structure, which can be well embedded in the P-band array structure. In order to verify the feasibility of the scheme, prototype processing and testing were carried out, and the test results are consistent with the simulation results. The active VSWRs of the overall design are less than 2.0. Additionally, the dual-band antenna array has favorable radiation performance in each frequency band. It can be used in forest biomass measurements and other interferometric applications. [ABSTRACT FROM AUTHOR]

A novel additive-manufactured antenna for stretchable sensor application is designed, simulated and measured. The fully transparent antenna has air as a substrate and a conductive aluminium metal sheet as a patch. The layers are defined with thin Thermo Poly Urethane (TPU) material, as its flexible/stretchable property doesn't disturb the actual property of air. The air substrate is locked within the flexible TPU with a thickness of 200 microns, and the conducting patch is also dimensioned with the 3D printing method. The stretchable antenna is fabricated with 3D printing technology, considered a dielectric medium, and the conducting medium is a conducting aluminium sheet. Re-configurability is achieved with the pressure level applied over the air–substrate antenna. Hence, the minimal change in shape changes the dielectric constant, thus changing the antenna parameter and radiation pattern. The antenna achieves improved size and performance with a gain of 7.2 dB, a directivity of 7.574 dB, a radiation efficiency of 95.67 %, and a 12:509 front-to-back ratio. The fabricated antenna is tested for its resonant characteristics and radiation properties. This reconfigurable antenna can be used for various applications, including Wireless Local Area Network (WLAN) communication. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to propose a single element, dual feed, polarisation diversity antenna. The proposed antenna operates from 2.9 to 10.6 GHz for covering the entire ultra-wideband (UWB) frequency range. The antenna is designed for usage in massive multiple input multiple output (MIMO) and closed packaging applications. Design/methodology/approach: The size of the antenna is 24 × 24 × 1.6 mm3. The radiating element of the antenna is derived from the Sierpinski–Knopp (SK) fractal geometry for miniaturization of the antenna size. The antenna has a single reflecting stub placed between the two orthogonal feeds, to improve isolation. Findings: The proposed antenna system exhibits S11 < −10 dB, S21 < −15 dB and stable radiation characteristics in the entire operating region. It also offers an envelope correlation coefficient < 0.01, a diversity gain > 9.9 dB and a capacity loss < 0.4 bps/Hz. The simulated and measured outputs were compared and results were found to be in similarity. Originality/value: The proposed UWB-MIMO antenna has significant size reduction through usage of SK fractal geometry for radiating element. The antenna uses a single radiating element with dual feed. The stub is between the antenna elements which provide a compact and miniaturized MIMO solution for high density packaging applications. The UWB-MIMO antenna provides an isolation better than −20 dB in the entire UWB operating band. [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]

Detection and perception problems may occur when the amplitude level of some signals that need to be received and detected is weak. Information that is requested to be kept confidential or not shared with other units is always available in the environment as wireless electromagnetic (EM) waves. Detection can only be made with the appropriate method. Thermal radiation emitted by objects that are intended to be hidden under clothing can also be given as an example. The signal level of these EM waves is very low. In this case, low noise amplifier (LNA) circuits are used to increase such values to a measurable level by network analyzer. In this study, a design with 17.19 dB gain for WLAN applications is made using BL011 LNA chip gathered from BeRex company with a 3rd order band pass filter (BPF) at 2.4 GHz center frequency, it has 200 MHz band width (BW) and 50 ohm characteristic impedance. An innovation has been introduced to design BPF as using the geometric mean prototype element values (PEV) by the help of geometric mean of 4 known techniques: Butterworth, Chebyshev (0.5 dB ripple), Bessel and Gauss (to 12 dB) normalized table values. According to the researches, the BPF circuit created by the geometric averaging method with the BL011 LNA chip has never been used to detect hidden EM signals in the WLAN band. Finally, the proposed BPF circuit is 2 in total, one at the input and one at the output; LNA circuit designed by using BL011 module and impedance matching circuit, a total of 3 consecutively connected and combined systems are formed. The proposed full system has the merits of compactness, good input reflection coefficient and good S21, gain characteristic. [ABSTRACT FROM AUTHOR]

In a dense IEEE 802.11 WLAN, arranging multiple access points (APs) to achieve suitable area coverage is an urgent problem that needs to be addressed. This paper proposes an elaborate AP selection strategy based on three types of criteria. Furthermore, to effectively implement the selection process, the AP selection decision is modeled as a limited non-cooperative game scheme, and a two-tier approximation game is adopted to determine the final selection decision for a centralized framework. Specifically, a criterion for guaranteeing wireless station (WS) fairness is proposed to realize AP selection. This algorithm takes into account the varying throughput requirements of WSs and maximizes the total throughput Quality of Service (throughput-QoS) of all WSs, thereby enhancing WS satisfaction. Additionally, this paper introduces a load-balancing AP selection algorithm aimed at enhancing network load balancing. In this algorithm, the load balancing index is optimized to distribute the load evenly among APs, thus enhancing resource utilization within the network. Moreover, a joint optimization AP selection algorithm is presented. It employs a joint optimization index to measure the comprehensive performance of the network, striking a balance between average network throughput-QoS and load balancing. Numerical simulations prove the effectiveness of the proposed AP selection strategy incorporating three different criteria. Under larger number of WS, they can improve total throughput-QoS 10%, make load balancing and multi-attribute weighted index reach 0.9770 and 0.6356, respectively. [ABSTRACT FROM AUTHOR]

Multiband MIMO antenna system is very important in 5G mobile communication to meet the requirements of increasing data rate. However integrating multiple antennas in the limited space causes mutual coupling. The antenna configuration gets more intricate, if additional circuitry is installed to obtain greater isolation and hence, the occupied area on the board grows significantly, making the overall antenna design bulky. Hence, to provide dual band coverage, decent isolation and compact design, a compact MIMO antenna system is presented in this paper. The proposed system includes a T-shaped resonating structure that is employed on the side-frames to form a MIMO system with eight antennas. The T-shaped strip is designed to resonate at two frequencies and thereby covering two 5G bands (LTE 42/LTE 46). The proposed dual band MIMO system is fairly compact as the individual antennas are mounted on the 150 × 3.6 mm 2 side-frames of the smartphone. The isolation between antenna elements is 14 dB. This is accomplished without the need of a decoupling structure or a complex tuning process. The ergodic channel capacity realized by the suggested MIMO system in the operational bands is more than 41 b/s/Hz and ECC is less than 0.075. The impacts of the presence of plastic frame, display panel and phantom hand on the performance of proposed design are discussed. The proposed design provides compactness, dual band coverage and high isolation. [ABSTRACT FROM AUTHOR]

In this paper, we design and simulate a 28/38 GHz dual-band multiple-input multiple-output (MIMO) patch antenna array that operates in the FR2 frequency band (28 GHz and 38 GHz). This antenna array comprises four similar patch antennas with a rectangular "L minus two slots" shape. In addition, it applies to 5G electronic components such as a smartphone. We used high-frequency structure simulator (HFSS) software to perform the design and simulation for this antenna. In addition, this proposed antenna array provides better performance, such as; bandwidth around 28 GHz is equal to 0.69 GHz and 38 GHz is equal to 0.86 GHz, equal gains 5. 9 dB at 28 GHz and 9 dB at 38 GHz, directivities are 6.3 dB at 28 GHz and 9.4 dB at 38 GHz, the efficiency of 95.38% at 28 GHz, and efficiency of 96.53% at 38 GHz. [ABSTRACT FROM AUTHOR]

Microstrip patch antennas are becoming increasingly popular because they are small, have low profiles, are easy to integrate, are very cheap, and work well. For this reason, this antenna could be used for wireless communication systems. This research paper reviews and studies 28 GHz microstrip patch antenna for wireless applications. Different substrate materials have been used to make these antennas, such as FR-4 (loss), FR-4 Epoxy, Rogers RT/droid 5880, TLC-30, Rogers RT/droid 5880 LZ, and others. Different substrate materials and shapes were used to make microstrip patch antennas with a frequency of 28 GHz. This article discusses the different sizes of antennas, the other geometric shapes antennas can take, the different ways antennas' properties can be analyzed, and the different types of antennas. It will also talk about the material, thickness, loss tangent, return loss, bandwidth, voltage standing wave ratio (VSWR), gain, efficiency, and directivity of the substrate. This antenna is used for super-high-frequency (SHF), radars, commercial wireless local area networks (LANs), cell phones, and other wireless communications systems. [ABSTRACT FROM AUTHOR]

This research presents the design and analysis of a compact MIMO antenna tailored for 5G millimeter-wave applications, specifically targeting bands N257, N260, and N262. The antenna, characterized by its straightforward design, maintains compact dimensions of 10 mm × 16 mm while delivering exceptional performance with high gain. Employing Rogers RT/Duroid 5880 substrate material with a thickness of 0.508 mm, the antenna consists of two crescent-shaped radiating elements (patches) situated on the top surface of the dielectric material, complemented by a slotted ground on the bottom. The radiating elements are fed through a 50-Ω microstrip line. Operating across three distinct bands, the antenna's capabilities are outlined as follows: the first band spans from 27.2 to 29 GHz, centering around 28 GHz; the second band encompasses the frequency range from 34 to 40.2 GHz, with a center frequency of 39 GHz achieved through slotting crescent-shaped radiating elements; the third band, ranging from 47.5 to 51.3 GHz with a center frequency of 48.7 GHz, is attained by engraving circular slots on the ground. To validate simulation outcomes, a hardware prototype of the antenna is manufactured, showcasing excellent agreement between simulations and measurements. The antenna design is implemented using the CST Microwave Studio software tool and is benchmarked against existing literature. Key attributes of the proposed antenna include its compact size, simple geometry, wide bandwidth, and high gain. The antenna's favorable MIMO parameters (ECC, TARC, DG, and CCL), coupled with minimal spacing between elements, position it as a promising candidate for forthcoming 5G millimeter-wave communication applications. [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]

This article discusses the development and analysis of a broadband filter capable of suppressing specific frequencies of wireless applications at 4.7 GHz for WLAN, 8.3 GHz, and 11.5 GHz (for satellite communication) by combining a T-shaped stub loaded resonator with a central square ring to achieves high performance and compact size within the bandwidth of interest. The filter achieves low signal loss of 0.4 dB across the entire passband of 14.9 GHz bandwidth, good reflection suppression exceeding 10 dB, and independently adjustable multi stopbands. It utilizes a simple planar topology for a small footprint of 0.52 λ g × 0.32 λ g , where λ g represents the wavelength at 4.7 GHz. The proposed filter evaluated using classical method an even-odd-mode analysis, and a 3D software tool HFSS-15 is used for simulations. The physical prototype is built on a Rogers RO-4350 substrate using LPKF S63 ProtoLaser machine. To confirm the accuracy and performance of the prototype, measurements were conducted using a ZNB20 vector network analyser. The simulations and measurement results confirm its effectiveness, paving the way for applications in various fields such as radar systems, medical imaging, and wireless communication. [ABSTRACT FROM AUTHOR]

The ever-growing miniaturization of electronic devices is foremost due to a wide range of changes in shrinking the wearable devices. This article focuses on a small, wearable antenna with dual bands for 5G and Wi-Fi communications. The Frequency Selective Surface (FSS) is made of denim Jean and has a top- loaded stubs-inspired radiator and a modified ground plane structure to induce the resonance frequencies at 3.5 and 5.8 GHz within a compact 31.5 mm × 26 mm size. With the FSS integrated antenna, you can cover the N-78 5G band-width of 620 MHz (S11 × −10dB) in the 3.28–3.9 GHz range, as well as the Wi-Fi bandwidth of 600 MHz (S11 × −10 dB) in the range of 5.65–6.25 GHz. The antenna presented has a peak gain of 7.07 dB at 3.5 GHz and 6.02 dB at 5.8 GHz. This antenna is mounted near a human arm model lowering the Specific Absorption Rate (SAR) to 0.370W/kg at 3.5 GHz and 0.870W/kg at 5.8 GHz. The simulated values are validated with measured results and are suitable for body area communication. The designed FSS antenna provides stable impedance bandwidth for conformal applications with enhancing radiation performance. [ABSTRACT FROM AUTHOR]

This paper presents a novel circular fractal ring monopole antenna for ultra‐wideband (UWB) hardware with dual band‐notched properties. The proposed antenna consists of four crescent‐shaped nested rings, a tapered feeding line at the front of the dielectric material, and a semicircular ground plane on the backside. In this design, the nested rings are used both as a radiation element and a band rejection element. The proposed antenna has a bandwidth of 9.03 GHz, which works efficiently in the range of 2.63 GHz–11.66 GHz with the dual notched bands of Worldwide Interoperability for Microwave Access (WiMAX) at 3.15 GHz–3.66 GHz and wireless local area network (WLAN) at 4.9 GHz–5.9 GHz, respectively. The antenna has a compact size of 20 mm × 30 mm × 1 mm (0.177 × 0.265 × 0.0084 λ0) and is implemented using a flame‐retardant type 4 (FR4) material. It has a maximum gain of approximately 4 dB in its operating range, and experimental results support the simulation predictions with high accuracy. The findings of this study imply that the designed antenna can be utilized in UWB 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]

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Wearable textile antennas have obtained remarkable attention in various medical fields due to their ease of integration and flexibility. This paper puts forward an Ultra Wide Band (UWB) Compact Textile Wearable Antenna (CTWA) for Wireless Body Area Network (WBAN) applications. The proposed antenna is a semicircular slotted elliptical antenna with an L-shaped stub and a partial defected ground plane. The antenna is fabricated on denim jeans (ϵr = 1.77) and has an overall dimension of 27×28×0.7 mm with an operating frequency range 3.01-15.98 GHz, radiation efficiency of 83.5-90.11%, and maximum gain of 5.81 dBi. Structural deformation studies including human body loading of the antenna are carried out, and the performance of the antenna is found to be stable. The proposed antenna has a low profile and high fractional bandwidth (137%) compared to the UWB wearable antennas reported in the literature. The calculated Specific Absorption Rate (SAR) of the antenna at the frequencies 4,7 and 10 GHz are 1.2, 1.06, and 1.58 W/Kg, respectively, which lies within the FCC (Federal Communications Commission) standard. The proposed CTWA is compact, flexible, wearable, and robust, which makes it suitable for on-body WBAN applications. [ABSTRACT FROM AUTHOR]

In this article, a low profile multiband and multistrip with microstripfed triple L shaped monopole antenna has proposed. The antenna is designed to operate at 1.8GHz, 3GHz and 5.8GHz bands for GSM, WLAN and WiMAX applications. Including insert three L strip to generating multiband operation and the impedance bandwidth are coving frequency range 1.7GHz -1.88GHz/1.8GHz, 2.8 GHz -3.4GHz/3GHz and 5.4GHz-6.8GHz/5.8 GHz. The proposed antenna total occupied area is 27x40xmm³ and impedance bandwidth are achieved are 22%, 20% and 24%. The antenna is design on ANSYS HFSS software. Radiation pattern of proposed antenna is crating of omni-directional. The proposed antenna has very miniaturized than the references antenna are discussed in this article. [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]

This paper introduces the design of a multiple-input-multiple-output (MIMO) antenna optimized for low-profile applications supporting sub-6 GHz fifth-generation (5G) wireless applications. We have started the design from a single antenna with a square patch shape, each antenna array is composed from 4-element radiators fed by using power dividers and quarter microstrip lines. Mounted on a single Rogers RT5880 substrate, the MIMO antenna functions at 3.5 GHz. In order to miniature and to decrease the mutual coupling between the both antennas array we have optimised a magnetic wall based on periodic structures permitting to decrease the mutual coupling between the both antenna array. The unit element from the wall was optimised, studied and validated in order to absorb the surface current and to enhance the isolation between the different radiating elements. The dimensions of the proposed MIMO antenna are 154×220×0.578 mm². The MIMO antenna final circuit achieves a peak gain of 9 dBi and an isolation around -30 dB. The introduction of the magnetic wall permits to enhance the isolation between the antenna array from -20 dB to -30 dB at 3.5 GHz band. This advancement contributes to the overall performance improvement of the MIMO antenna system. [ABSTRACT FROM AUTHOR]