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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]

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]

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 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]

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]

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]

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]

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 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]

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]

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]

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]

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]

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This paper presents rooftop automobile antennas designed for Long-Term Evolution (LTE), Wireless Local Area Network (WLAN) and navigation system applications. The proposed antennas are housed within a shark-fin structure on the car's roof, and comprise a main antenna and a diversity antenna. The main antenna and diversity antenna combine for spatial diversity, receiving and processing the same signal to optimize signal quality. To accommodate the limited space within the shark-fin housing, various miniaturization and multiband techniques are utilized. The hexagonal substrate is more closely fitted to the shape of the shark fin, thus making full use of the space of the shark-fin shell. The main antenna and the diversity antenna are perpendicular to each other, which saves the space of the overall antenna and improves the utilization rate of the overall antenna space. The proposed main antenna, compactly sized at 50 mm × 20 mm × 1.59 mm, maintains a VSWR value below 2 across the frequency range of 1.19–2.8 GHz, enabling support for LTE bands 1, 2, 3, 4, 7, 11, 15, 16, 34, 39, 40, and 41, as well as WLAN 2400 bands. The diversity antenna maintains a VSWR value below 2 across the frequency range of 1.5–2.6 GHz, which can cover BeiDou B1-1, LTE 1, 2, 3, 4, 7, 11, 15, 16, 34, 39, and 40, and WLAN 2400 bands. The main antenna and the diversity antenna both demonstrate favorable radiation patterns on the azimuth plane. Simulation and measurement results exhibit a high level of agreement. [ABSTRACT FROM AUTHOR]

This article presents a 3.5 GHz rectangular microstrip patch antenna (RMPA) designed, studied, and analyzed for wireless LAN applications. Using Fr-4 as substrate material, whose dielectric permittivity is 4.3, patch thickness is 1.65 mm, and loss tangent is 0.025. A feeding line with an impedance of 50 Ω is utilized to supply the antenna with power. Computer simulation technology (CST) software has been used to design the antenna and origin pro software has been used to display the resulting figures from the simulation. The antenna simulation showed that the return loss is -56.82 dB; the directivity gain is 6.02 dBi, the bandwidth is 0.148 GHz, and the voltage standing wave ratio (VSWR) is 1.0028. The paper aims to increase the return loss, develop a standard VSWR, increase the directivity gain of the antenna, and improve the antenna bandwidth. The results of the proposed antenna were much better than previously published papers, which were suitable for wireless applications. This proposed antenna can be used for future wireless LAN applications. [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]

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]

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]

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]

Summary: A small size, dual‐band and dual‐sense monopole antenna is proposed to improve the axial ratio bandwidth (ARBW). The proposed antenna is considered on a low‐cost lossy FR4 substrate with parasitic strips (PSs) and partial ground plane of half guided wavelength dimensions. The dimension of the antenna in terms of wavelength is 0.27λ0×0.29λ0×0.02λ0, where λ0 is the wavelength at the lowest resonant frequency. The circularly polarized (CP) mode is created for strong orthogonal electric fields EX and EY. The obtained phase difference (PD) between two electric fields EX and EY is varied from 86° to 96° under ARBW. The achieved ARBW is 3.68–3.8 GHz, 4.84–12.58 GHz, and impedance bandwidth (IBW) is 3.51–3.82 GHz and 4.28–15 GHz. The applications of the proposed antenna are International Telecommunication Union (ITU) for 5G, C‐band IEEE 802.11a wireless local area network (WLAN) at 5 GHz (5.15–5.825 GHz) and X‐band wireless systems. [ABSTRACT FROM AUTHOR]

This letter constitutes a novel triple-band reconfigurable filtering antenna used for Bluetooth, WiMAX and WLAN applications. First, a compact triple-band reconfigurable filter is instigated which is composed of two pairs of Stepped Impedance Resonators (SIRs) and a pair of Uniform Impedance Resonators (UIRs). The SIRs are entrenched at the upper and lower half of feed lines operating at 2.4 and 5.4 GHz, respectively. A pair of UIRs operating at 3.5 GHz is folded and enclosed near the upper SIR. A shunt stub is tapped at the source-load feeding lines to upgrade the selectivity of the filter. The proposed filter uses four PIN diodes to initiate different reconfigurable multiband operations. A fractal antenna is implemented with a modified binary tree topology. The ground plane of the proposed antenna is reformed with a stub. The improved antenna structure enables three radiating bands with enhanced performance. Later, the designed filter is integrated into the antenna to implement the intended triple-band reconfigurable filtering antenna. [ABSTRACT FROM AUTHOR]

From connected sensors in soils, on animals or crops, and on drones, to various software and services that are available, "smart" technologies are changing the way farming is carried out. These technologies allow producers to look beyond what the eye can see by collecting non-traditional data and then using analytics tools to improve both food sustainability and profitability. "Smart Agriculture/farming" (SA) or "Digital Agriculture" (DA), often used interchangeably, refer to precision agriculture that is thus connected in a network of sensing and acting. It is a concept that employs modern information technologies, precision climate information, and crop/livestock developmental information to connect production variables to increase the quantity and quality of agricultural and food products. This is achieved by measuring and analyzing variables accurately, feeding the information into the cloud from edge devices, extracting trends from the various data, and subsequently providing information back to the producer in a timely manner. Smart agriculture covers many disciplines, including biology, mechanical engineering, automation, machine learning, artificial intelligence, and information technology-digital platforms. Minimum standards have been proposed for stakeholders with the aim to move toward this highly anticipated and ever-changing revolution. These foundational standards encompass the following general categories, including precise articulation of objectives, and baseline standards for the Internet of Things (IoT), including network infrastructure (e.g., stable 4G or 5G networks or a wireless local area network (WLAN) are available to end users). To sum up, SA aims to improve production efficiency, enhance the quality and quantity of agricultural products, reduce costs, and improve the environmental footprint of the industry. SA's ecosystem should be industry self-governed and collaboratively financed. SA stakeholders and end-users' facilities should meet standard equipment requirements, such as sensor accuracy, end data collectors, relevant industry compliant software, and trusted data analytics. The SA user is willing to be part of the SA ecosystem. This short perspective aims to summarize digital/smart agriculture concept in plain language. [ABSTRACT FROM AUTHOR]

This paper presents the design and prototype development of a compact frequency‐selective surface (FSS) for shielding WLAN signals. The FSS unit‐cell geometry is evolved by modifying the arms of the conventional crossed dipole element. The footprint of the unit cell is only 6 mm × 6 mm × 1.6 mm. The proposed FSS offers stop band characteristics at 5 GHz for both transverse electric (TE) and transverse magnetic (TM) modes. In addition, the FSS offers angular stability up to 60°. A prototype of the proposed FSS is fabricated and measured to validate its simulations. Measured bandwidth of the stop band is 410 MHz, referenced at −20 dB for both TE and TM modes. Equivalent circuit model of the FSS is derived and the results are compared with the simulations. [ABSTRACT FROM AUTHOR]

A novel‐shaped dual‐polarized low‐profile multiple‐input multiple‐output (MIMO) antenna with high isolation is proposed for 5G/WLAN application. An 8‐element MIMO antenna design comprises two unique planar radiators (chamfer, circular). Each radiator has dual feed and dual polarization characteristics. The prototype is fabricated with an FR‐4 dielectric substrate. A decoupling structure maintains desirable isolation for self‐isolated elements (≤ $\le $−12 dB) using substrate integrated waveguide stubs between inter‐ports and high isolation among the adjacent radiating elements (≤ $\le $−15 dB). The simulation was performed by using CST microwave studio. The simulated results of the proposed MIMO antenna are compared with the measurement results. Furthermore, ECC and DG are investigated. [ABSTRACT FROM AUTHOR]

Background: Clinical evaluation of swallowing provides important clinical information but is limited in detecting penetration, aspiration, and pharyngeal residue in patients with suspected dysphagia. Although this is an old problem, there remains limited access to low-cost methods to evaluate swallowing safety and efficiency. Purpose: The purpose of this technical report is to describe the experience of a single center that recently began using a wireless Wi-Fi intraoral camera for transoral endoscopic procedures as an adjunct to clinical swallowing evaluation. We describe the theoretical structure of this new clinical evaluation proposal. We present descriptive findings on its diagnostic performance in relation to videofluoroscopic swallowing study as the gold standard in a cohort of seven patients with dysphagia following head and neck cancer. We provide quantitative data on intra- and interrater reliability. Furthermore, this report discusses how this technology can be applied in the clinical practice of professionals who treat patients with dysphagia and provides directions for future research. Conclusions: This preliminary retrospective study suggests that intraoral cameras can reveal the accumulated oropharyngeal secretions and postswallow pharyngolaryngeal residue in patients with suspected dysphagia. Future largescale studies focusing on validating and exploring this contemporary low-cost technology as part of a clinical swallowing evaluation are warranted. [ABSTRACT FROM AUTHOR]

We have presented two-port MIMO antenna designs with low-profile material. Two different MIMO antenna designs are prepared and investigated to observe their effect on the gain, bandwidth, etc. The designs are prepared based on metasurface concepts with one design having a circular ring metasurface design and second having circular disk metasurface design. The designs are showing broadband response covering frequency range of 1.85 GHz to 4.27 GHz. The bandwidth of 2.320 GHz is achieved for this metasurface MIMO antenna design. The gain and directivity results show that highest gain of 5.88 dB and directivity of 6.39 dB are achieved with circular ring metasurface MIMO antenna design. Both metasurface MIMO antenna designs are fabricated, and measured results are also provided to verify the simulation results. The broadband and high gain design are applicable for 5G communication, WiMAX and WLAN applications. [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]

In this work, a compact quadruplet arrow slotted elliptical shaped notch band printed microstrip antenna is designed and analyzed for modern wireless communication systems. Initially, a compact elliptical-shaped antenna model with defected ground structure is designed for ultra-wideband (UWB), having a working range of 3.1 to 10.6 GHz. The design was modified with a quadruplet arrow slot which resulted in single-notch band characteristics for wireless LAN bands. The realized peak gain of the recommended antenna is 5.11dBi at a frequency of 3.7 GHz. The analysis of the suggested antenna has been performed by evaluating different geometrical shapes. The surface current distribution analysis is also presented to provide a clear insight on the working principle of the antenna. The various characteristics parameters such as return loss, gain, radiation patterns are presented and discussed. The suggested antenna model occupying a total dimension of 26 × 24 × 1.6 mm³ in size is simulated and its results are investigated with CST tool. The designed antenna is prototyped over FR4 substrate for measurement validation. The simulation results of the prescribed antenna are matched with experimental data for validation. The findings indicate that the suggested compact antenna is well-suited for high-speed, close-range communication and can effectively reject signals from the WLAN band. [ABSTRACT FROM AUTHOR]

A compact new ultra-wideband (UWB) antenna using planar metamaterial (MTM) structures is proposed. The antenna is designed with a double-side planar periodic cell structure. The proposed 3-D unit cell show an artificial negative electric permittivity medium (NEPM), exhibiting a wide electromagnetic bandgap (EBG) created by etching four L-shaped slots on the main square patch and crossed-shaped slots on the ground plane. The proposed antenna fabricated on a 1.52 mm low-cost Rogers RO4003C substrate, is compact, measuring 22.4 × 25.6 mm², with a relative permittivity of 3.38 and a loss tangent of 0.0027. It has a broad bandwidth covering 3.8 GHz to 17.7 GHz, relatively 129%. The average gain over the entire bandwidth is 5.44 dB, with a peak value of 8.55 dB at 15.5 GHz. Design and simulation were carried out using the finite integration technique (FIT)-based CST microwave studio. The measured return loss (S11) of the prototype was in good agreement with the simulated results. The proposed antenna shows satisfactory radiation efficiency, achieving between 80% and 93% over the whole band. The measured gain of the test antenna demonstrates favorable radiation characteristics and shows the stability of radiation patterns at low frequencies. A comparative study with the related literature reviews recently published highlights the compactness of our MTM antenna configuration, presenting a reduction factor between 43.13% and 56.25%. Due to its outstanding performance, the proposed design is positioned as a strong candidate for various UWB applications, and also can be used for satellite communications and radar applications. [ABSTRACT FROM AUTHOR]

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The development of radio frequency circuits is currently guided mainly through two objectives, which are size reduction and performance improvement of devices. Within a reception or transmission channel, the division and/or combination of power are the most delicate stages due to their large dimensions and high insertion losses, particularly in the case of dividers/combiners based on planar technologies. In this context, this study proposes an analysis and design of a new broadband power divider and combiner using stepped impedance. The power divider/combiner developed is designed to cover a broad frequency spectrum ranging from 1 GHz to 4 GHz, including wireless applications such as Global Mobile Communications Systems (GSM), Industrial, Scientific and Medical (ISM), and Sub-6 GHz 5th Generation (5G) applications. The proposed circuit was analyzed using the stepped transmission line impedance method and designed by Advanced Design System (ADS) on an Epoxy-FR4 substrate with a dielectric constant of 4.4 and a thickness of 1.58 mm. The achieved results showed excellent characteristics in terms of transmission across the input and output terminals, mismatches at all three terminals, and isolation among output terminals. A prototype was built and the measured results showed good agreement with those obtained by simulation. [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]

This article presents the design of a multiband microstrip MIMO antenna for millimeter-wave (mm-Wave) applications, which are crucial for 5G networks. The antenna, designed using an Artificial Neural Networks (ANN) approach, specifically a multilayer perceptron, consists of four microstrip elements on a Rogers RT/Duroid 5880 dielectric substrate. The dimensions of the antenna are 31 × 22 × 0.79 mm². Operating at frequencies of 24, 31, and 36 GHz, the antenna is suitable for satellite communications, high-resolution radar, and point-to-point communications. The dimensions of the slots are determined using the ANN technique. A prototype of this MIMO antenna, featuring neutralization lines, has been simulated and tested, demonstrating mutual coupling of less than -24.8 dB between ports. The antenna offers an efficiency of 94.3%, gains of 7.63 dBi, 7.61 dBi, and 6.25 dBi at different frequencies, and a suitable radiation pattern. The Envelope Correlation Coefficient (ECC) is below 0.006, and the maximum Diversity Gain (DG) is approximately 9.98 dB. The Total Active Reflection Coefficient (TARC) is stable, meeting the requirements for various wireless MIMO applications. [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 novel multiband patch antenna with a modified hexagonal structure is introduced in this paper to target the most required frequencies used for radio frequency energy harvesting applications, including WLAN-2.4G, WLAN-5G, WLAN-6G (Wireless Local Area Network), Mobile LTE (Long Term Evolution), and WIMAX (Worldwide Interoperability for Microwave Access). A novel fractal shape is designed and combined with a conventional hexagonal geometrical shape in order to implement the front patch of the antenna. The proposed antenna is simulated with CST Studio Suite software and fabricated on FR-4 substrate. Different antenna stages with parametric study and optimization were implemented to get the best performance from the proposed antenna. The proposed multiband antenna (Antenna-1) supports four resonate frequencies (2.4045 GHz, 3.568 GHz, 4.6405 GHz, 5.869 GHz) and has a high gain of (3.2 dBi) at the frequency of 2.4045 GHz. The proposed antenna covers all of the WLAN-2.4G (IEEE 802.11) frequency band and achieved a maximum bandwidth of (0.5101 GHz) at a frequency of 5.869 GHz, making it a suitable antenna for radio frequency energy harvesting applications. The measured results have shown good agreement with the simulation results. Furthermore, an evaluation of this proposed work in comparison to other published works highlighted the advantages in terms of antenna thickness, size, gain, and the number of supported operating frequencies. Also, the comparison showed that the FR-4 substrate used to implement this proposed work is much cheaper than other substrate types used to implement other published works. [ABSTRACT FROM AUTHOR]

This study describes the design and implementation of microstrip bandpass filter for 5G applications. The proposed bandpass filter analysis was carried out using ANSYS ELECTRONIC DESKTOP. The filter has been modelled, fabricated and its performance has been evaluated using MS2037C Anritsu Combinational Analyser. The proposed filter measures 40x40x1.6 mm³, which is significantly smaller. An impedance bandwidth of 3 GHz (fractional bandwidth of 30%) has been achieved. Insertion loss of 1 dB, impedance bandwidth of 3 GHz and a quality factor of 9.5, 5.71, and 10.73 has obtained at 2.28 GHz, 4.07 GHz, and 4.94. The designed bandpass filter occupies 50% space of the conventional filter. These results make the semi-Circular cavity bandpass filter suitable for n1, n40, n41, n77 n78 and n79 5G bands. [ABSTRACT FROM AUTHOR]

Technology is advancing daily, and it has impacted almost every aspect of our lives. We show that growth in the number of miniaturized communications systems that are covering different wireless services can achieve a wide frequency range. The present work aims to propose a new rigorous formulation to model a reconfigurable array system used for different wireless applications. The studied structure consists of a reconfigurable antenna array composed of parallel microstrip antennas excited by localized voltage sources and commanded by located PIN diodes. Diodes are used to adjust the length of the radiating element in order to shift the resonant frequency. The proposed formulation consists to combine the moment method and generalized equivalent circuit's method (MoM-GEC) to model the antenna array. The PIN diode is considered in the mathematical formulation by an impedance surface model. The input impedance, the reflection parameter ( S 11 ) and the current distribution density obtained with this method are presented and discussed. The results were in close agreement with those obtained by software simulation. The obtained results offer the possibility to generate various modes governed by a decision tree. Thus, these modes are related to different resonant frequencies suitable for RFID, WiMax and WLAN applications with a large bandwidth reaching 526 MHz. [ABSTRACT FROM AUTHOR]

A novel design of a dumbbell shape quad elliptical slotted (DSQES) antenna for directive ultra-wideband (UWB) integrated with WCDMA, WLAN, and mid-band of 5G applications is presented. Initially, a circular patch is designed by inserting four elliptical slots in radiator with a rectangular slotted ground plane. To realize ultra-wide impedance bandwidth, three symmetrical stepped rectangular slots are inserted in ground below a stepped-quarter-wave-transformer feed line. The proposed antenna achieves fractional bandwidth (FBW) of 104% (S11 < −10 dB) which covers UWB frequency range of 5.4–17.3 GHz at resonant frequencies 5.8/7.4/10.3/12/15.7 GHz. Further, a ground structure is customized by loading two asymmetrical meander strip resonators (MSRs), which provides extra lower frequency bands 2.1 GHz (1.96–2.21 GHz) and 3.5 GHz (3.22–4.07 GHz) for WCDMA, WLAN, and 5G mid-band applications, respectively. Furthermore, the measured gain and half-power-beam-width (HPBW) are 1.7–6.4 dBi and 75◦ –20◦ in 5.4–17.3 GHz UWB, respectively. The optimized dimension of proposed antenna is 30 × 30 mm² which is simulated on Computer Simulation Technology (CST) electromagnetic simulator using an FR-4 substrate of thickness 1.6 mm and dielectric constant 4.3. The simulated structure is computed by ADS simulator, and simulated results are validated with measured ones. [ABSTRACT FROM AUTHOR]

A Sierpinski Gasket Fractal Structure embedded in an Octagonal Microstrip Printed Monopole Antenna is proposed. The prototype is mathematically developed in a miniaturized cross-sectional area with ultra-wide resonance. A fractal design resembling a third-order Sierpinski gasket is applied to the octagonal radiator in a mutually proportional manner, increases the radiation across the entire surface area by extending the effective length of the dielectric. The driven radiator exhibits Fractional Bandwidth (FBW) of 156% spanning at 2.65 GHz–21.6 GHz, along with a peak gain 6.23 dB. The fabricated prototype demonstrates excellent agreement during testing and measurement using a microwave analyzer and an anechoic chamber, respectively. The proposed antenna covers resonance for applications at the S, C, X, and Ku bands. Also, it completely envelopes the Ultra-Wideband (UWB) and Sub-6 GHz 5G spectrum. [ABSTRACT FROM AUTHOR]

: The purpose of this study is to design a multiband antenna using metamaterial for efficient satellite communication. The majority of the antennae described in the available research suffer from a variety of limitations, including intricate designs, great footprints, and erratic radiation patterns. Therefore, there is a significant demand for antennae that are of a smaller size but nevertheless perform well. This paper proposes a quad-band stub-incorporated split octagonal ring antenna for satellite communication-dependent wireless applications. The suggested antenna is built on an FR4 substrate that measures 22 × 39 × 1.6 mm³. CST EM studio software is used for the entire simulation. The proposed antenna resonates at four different bands, with operating frequencies ranging from 2.15 GHz to 2.30 GHz, 2.86 GHz to 3.76 GHz (due to stub 1), 4.47 GHz to 5.24 GHz (due to stub 2), and 5.67 GHz to 6.35 GHz (due to stub 3). (due to gap between the stub). The proposed antenna has resonant frequencies of 2.23 GHz, 3.28 GHz, 4.77 GHz, and 5.89 GHz, and bandwidths of 153 MHz, 9011 MHz, 7692 MHz, and 6813 MHz. Parametric analysis is used to select the best values. The designed antenna is built and tested. The measured and simulated values for return loss, gain, E-plane, and H-plane are compared, and they agree. Its dual-band operation, compact size, steady radiation pattern, and gain above 1 dBi across the whole resonating band make it suited for ISM, WIFI, WLAN, WIMAX, 5G, and C band satellite applications. [ABSTRACT FROM AUTHOR]

In this paper, mobile devices were used to estimate the received signal strength indicator (RSSI) of wireless channels with three wireless access points (APs). Using the RSSI, the path loss exponent (PLE) was adapted to calculate the estimated distance among the test points (TPs) and the APs, through the root mean square error (RMSE). Moreover, in this paper, the proposed adaptive PLE (APLE) of the TPs was obtained by minimizing the positioning errors of the PLEs. The training samples of RSSI were measured by TPs for 6 days, and different surge processing methods were used to obtain APLE and to improve the positioning accuracy. The surge signals of RSSI were reduced by the cumulated distribution function (CDF), hybrid Kalman filter (KF), and threshold filtering methods, integrating training samples and APLE. The experimental results show that with the proposed APLE, the position accuracy can be improved by 50% compared to the free space model for six TPs. Finally, dynamic real-time indoor positioning was performed and measured for the performance evaluation of the proposed APLE models. The experimental results show that, the minimum dynamic real-time positioning error can be improved to 0.88 m in a straight-line case with the hybrid method. Moreover, the average positioning error of dynamic real-time indoor positioning can be reduced to 1.15 m using the four methods with the proposed APLE. [ABSTRACT FROM AUTHOR]