Efficient broadband fractal antenna for WiMAX and WLAN.

This article presents a new design of a compact fractal antenna that operates across various wireless communication applications with wideband functionality. With a peak gain of 6.8 dB and a radiation efficiency ranging from 91% to 94%, the designed antenna operates in the frequency range of 3.2-7.5 GHz. The antenna consists of a rectangular radiator with integrated rectangular slots on one side of an FR4 substrate, while a partial ground plane is etched on the other side. The fabricated prototype was tested and measured. The results present a good agreement with the simulated results. The results presented by this antenna demonstrate high competitiveness for wireless communication applications such as Wi-Fi and WLAN and presents a promising solution to meet the increasing demand for compact and high-performance wireless communication devices. Additionally, the antenna has a small size of only 34 × 30 × 1.6 mm3, making it suitable for applications where space is limited. Overall, this paper provides an innovative and efficient design that offers excellent performance and is suitable for various wireless communication applications.

Characteristics of antenna fabricated using additive manufacturing technology and the potential applications.

Antennas play a critical role in modern technology. They are used in various devices and applications, including wireless communication, broadcasting, navigation, military, and space. Overall, the importance of antennas in technology lies in their ability to transmit and receive signals, allowing communication and information transfer across various applications and devices. Three-dimensional printing technology creates antennas using multiple materials, including plastics, metals, and ceramics. Some standard 3D printing techniques used to create antennas include Fused Deposition Modeling (FDM), Stereolithography (SLA), and Selective Laser Sintering (SLS). These antennas can be made in various shapes and sizes. 3D printing can help create complex and customized antenna designs that are difficult or impossible to produce using traditional manufacturing methods. 3D-printing technology has many advantages for building antennas, including customization, ease of fabrication, and cost-effectiveness. This review comprehensively evaluates the usage of 3D-printing technology in antenna fabrication.

Exploration of underlap induced high-k spacer with gate stack on strain channel cylindrical nanowire FET for enriched performance.

This research explores a comprehensive examination of gate underlap incorporated strained channel Cylindrical Gate All Around Nanowire FET having enriched performances above the requirement of the 2 nm technology node of IRDS 2025. The device installs a combination of strain engineering based quantum well barrier system in the channel region with high-k spacers sandwiching the device underlaps and stack high-k gate-oxide. The underlaps are prone to parasitic resistance and various short channel effects (SCEs) hence, are sandwiched by HfO2 based high-k. This SCE degradations and a strong electric field in the drain-channel region is rendered controlling the leakages. The strain based Nanosystem engineering is incorporated with Type-II heterostructure band alignment inducing quantum well barrier mechanism in the ultra-thin cylindrical channel region creating an electrostatic charge centroid leading to energy band bending and splitting among the two-fold and four-fold valleys of the strained Silicon layer. This provides stupendous electron mobility instigating high current density and electron velocity in the channel. Thereby, the device is susceptible to on-current enhancement via ballistic transport of carriers and carrier confinement via succumbing of quantum charge carriers. The device transconductance, Ion, Ioff, Ion/Ioff ratio are measured and the output performance (ID-VDS) characteristics is determined providing emphatic enrichments in contrast to the existing gate all-around FETs as well as the 2 nm technology node data of IRDS 2025. Hence, the strained channel Nanowire FET device developed here is presented here as the device of the future for various digital applications, RF applications and faster switching speed.

Quad-port multiservice integrated optically transparent automotive antenna for vehicular classification applications.

The demand for vehicular antennas increases in tandem with the need for multiple features in automobiles. The development of optically transparent antenna (OTA) has made it possible to deploy antennas on delicate surfaces such as glass. Earlier studies on OTA demonstrated its viability using materials such as transparent conducting oxides (TCO) and conductive polymers. A tri-band OTA is proposed in this paper for vehicular applications. The antenna operates at 1.8 GHz, 2.4 GHz and 3.39-12 GHz bands, covering automotive/wireless applications such as GSM, Bluetooth, Wi-Fi, vehicular communication and electronic toll collection. The proposed OTA is developed on soda lime glass, and the material TCO is used for the radiator and the ground plane. The antenna prototype is tested on windshield and in an anechoic chamber, the gain and efficiency are found to be greater than 1 dBi and 80%, respectively. Furthermore, a machine learning technique for vehicle classification is proposed, which could help in electronic toll collection, automatic vehicle identifier, and parking management applications. The presented algorithm achieves 80% classification accuracy with a minimum window size.

Primary intrapulmonary thymoma a case report.

Primary intrapulmonary thymoma (PIT), defined as the presence of thymoma tissue in the lung without an accompanying mediastinal component, is uncommon and so offers a diagnostic quandary. We describe the case of PIT in an 81-year-old man.

Evolution of type-II hetero-strain cylindrical-gate-all-around nanowire FET for exploration and analysis of enriched performances.

The incubation of strained nano-system in the form of tri-layered structure as nanowire channel in the cylindrical-gate-all-around (CGAA) FET at 10 nm gate length is developed for the first time to keep abreast with the proposed 3 nm technology node of IRDS 2022. The system installs Type-II hetero-strain alignment in the channel attesting itself as the fastest operating device debasing the SCEs at nano regime. The ultra-thin strained-channel comprises of two cylindrical s-Si wells encompassing s-SiGe barrier in between, which enables improvement of carrier mobility by succumbing of quantum charge carriers in the region. This results in 2D charge centroid creation with cylindrical based circular Nano-system contemplating electrostatic potential difference leading to enriched electric field, current density and transconductance, while the gate-all-around architecture with increased gate controllability lowers leakage current, in the device. The 10 nm strained-channel CGAA astounded havoc ON current enhancements of ~ 20% over 22 nm strained CGAA, 57% over Si CGAA FET and 75% over proposed 3 nm technology node IRDS 2022 are accomplished. Hence, carrier mobility and velocity enriches instituting quasi-ballistic transport through the Nanowire channel, thereby augments in ~ 28% drain current so the 10 nm channel CGAA FET stands as the most suitable and improved device in nano regime.

A Prospective Cohort Study (OUTSTRIP-COVID) on Functional and Spirometry Outcomes in COVID-19 ICU Survivors at 3 Months.

Purpose: COVID-19 pandemic resulted in a significant number of critical care admissions secondary to severe pneumonia and acute respiratory distress syndrome. We evaluated the short-, medium- and long-term outcomes of lung function and quality of life in this prospective cohort study and reported the outcomes at 7 weeks and 3 months from discharge from intensive care unit. Methods: A prospective cohort study of ICU survivors with COVID-19 was conducted from August 2020 to May 2021 to evaluate baseline demographic and clinical variables as well as determine lung function, exercise capacity, and health-related quality of life (HRQOL) using spirometry and 6-minute walk test (6MWT) conducted in accordance with American Thoracic Society standards, and SF-36 (Rand), respectively. SF-36 is a generic 36 question standardized health survey. Descriptive and inferential statistics (alpha = 0.05) were used to analyse the data. Results: At baseline, 100 participants were enrolled in the study of whom 76 followed up at 3 months. Majority of the patients were male (83%), Asians (84%) and less than 60 years of age (91%). HRQOL showed significant improvement in all domains of SF-36, except in emotional wellbeing. Spirometry variables also showed significant improvement in all variables over time with greatest improvement in percentage predicted Forced expiratory volume 1 (79% vs 88% p < 0.001). 6MWT showed significant improvement in variables of walk distance, dyspnea, and fatigue with greatest improvement in change in oxygen saturation (3% vs 1.44% p < 0.001). Intubation status did not impact the changes in SF-36, spirometry or 6MWT variables. Conclusion: Our findings suggest that ICU survivors of COVID-19 have significant improvement in their lung function, exercise capacity and HRQOL within 3 months of ICU discharge regardless of intubation status.

Development and Analysis of a Three-Fin Trigate Q-FinFET for a 3 nm Technology Node with a Strained-Silicon Channel System.

Multi-gate field effect transistors (FETs) such as FinFETs are severely affected by short-channel effects (SCEs) below 14 nm technology nodes, with even taller fins incurring fringing capacitances. This leads to performance degradation of the devices, which inhibits further scaling of nanoFETs, deterring the progress of semiconductor industries. Therefore, research has not kept pace with the technological requirements of the International Roadmap for Devices and Systems (IRDS). Thus, the development of newer devices with superior performances in terms of higher ON currents, acceptable leakage currents and improved SCEs is needed to enable the continuance of integrated circuit (IC) technologies. The literature has advocated integration of strained-silicon technology in existing FinFETs, which is highly effective in enhancing ON currents through the strain effect. However, the ON currents can also be amplified by intensifying the number of fins in trigate (TG) FinFETs. Thus, three-fin TG quantum (Q)-FinFETs, using a novel tri-layered strained-silicon channel, are deployed here at 10 nm and 8 nm channel lengths. Threshold voltage is calculated analytically to validate the designs. The electrical parameters and quantum effects of both devices are explored, analysed and compared with respect to existing heterostructure-on-insulator (HOI) FinFETs and the proposed existing standard requirement of IRDS 2022 for a 3 nm technology node. The comparisons demonstrated a significant increase in the drive currents upon employing three fins of the same dimensions (8 nm gate length) and specifications in a device-based system. The performance is augmented in contrast to the 3 nm technology node device of IRDS 2022, with SCEs within the limits. Thus, employing a tri-layered strained-silicon channel system in each fin allowed for forming a three-fin Q-FinFET that, in our opinion, is the technique for consolidating the performance of the devices and enabling future generation device for faster switching operation in a sub-nano regime.

Ultra-Wideband Compact Fractal Antenna for WiMAX, WLAN, C and X Band Applications.

In this paper, a compact dual-wideband fractal antenna is created for Bluetooth, WiMAX, WLAN, C, and X band applications. The proposed antenna consists of a circularly shaped resonator that contains square slots and a ground plane where a gap line is incorporated to increase the gain and bandwidth with a small volume of 40 × 34 × 1.6 mm3. The patch was supported by the FR4 dielectric, which had a permittivity of 4.4 and tan δ = 0.02. A 50 Ω microstrip line fed this antenna. The antenna was designed by the HFSS program, and after that, the simulated results were validated using the measured results. The measurement results confirm that the suggested antenna achieves dual-band frequencies ranging from 2.30 to 4.10 GHz, and from 6.10 GHz to 10.0 GHz, resonating at 2.8, 3.51, 6.53, and 9.37 GHz, respectively, for various applications including commercial, scholarly, and medical applications. Moreover, the antenna's ability to operate within the frequency range of 3.1-10.6 GHz is in accordance with the FCC guidelines for the use of UWB antennas in breast cancer detection. Over the operational bands, the gain varied between 2 and 9 dB, and an efficiency of 92% was attained. A good agreement between the simulation and the measured results was found.

Single-fed broadband CPW-fed circularly polarized implantable antenna for sensing medical applications.

Biomedical telemetry relies heavily on implantable antennas. Due to this, we have designed and tested a compact, a circularly polarized, a low-profile biomedical implantable antenna that operate in the 2.45 GHz ISM band. In order to keep the antenna compact, modified co-planar waveguide (CPW) technology is used. Slotted rectangular patch with one 45-degree angle slot and truncated little patch on the left end of the ground plane generate a frequency-range antenna with circular polarization. Using a 0.25-millimeter-thick Roger Duroid-RT5880 substrate with a thickness of εr = 2.2, tanδ = 0.0009 provides flexibility. The volume of the antenna is 21 mm x 13.5 mm x 0.254 mm (0.25λg × 0.16λg × 0.003λg). The antenna covers 2.35-2.55 GHz (200 MHz) in free space and 1.63-1.17 GHz (1.17 GHz) in epidermal tissue. With skin tissue that has more bandwidth, the (x and y)-axis bends of the antenna are also simulated via the simulation. Bended antenna simulations and measurements show excellent agreement. At 2.45 GHz, the skin-like gel had -10dB impedance and 3dB axial ratio (AR) bandwidths of 47.7 and 53.8%, respectively. The ultimate result is that the SAR values are 0.78 W/kg in skin over 1 g of bulk tissue, as determined by simulations. The suggested SAR values are lower than the FCC's maximum allowable limit (FCC). This antenna is small enough to be implanted in the body, making it perfect for biomedical applications.

Frequency Switchable Global RFID Tag Antennae with Metal Compatibility for Worldwide Vehicle Transportation.

This paper presents an effective way to design an RFID tag antenna to operate at three different frequencies by incorporating a switching technique. PIN diode has been used to switch the RF frequency because of its good efficiency and simplicity. The conventional dipole-based RFID tag has been improvised with added co-planar ground and PIN diode. The layout of the antenna is designed with a size of 0.083 λ0 × 0.094 λ0 at UHF (80-960) MHz, where λ0 is the free-space wavelength corresponding to the mid-point of the targeted UHF range. The RFID microchip is connected to the modified ground and dipole structures. Bending and meandering techniques on the dipole length help to match the complex chip impedance with the dipole impedance. Additionally, it scales down the total structure of the antenna. Two PIN diodes are placed along the dipole length at appropriate distances with proper biasing. The ON-OFF switching states of the PIN diodes enable the RFID tag antenna to switch over the frequency ranges (840-845) MHz (India), 902-928 MHz (North America), and 950-955 MHz (Japan).

UWB Circular Fractal Antenna with High Gain for Telecommunication Applications.

The present study proposes a new, highly efficient fractal antenna with ultra-wideband (UWB) characteristics. The proposed patch offers a wide simulated operating band that reaches 8.3 GHz, a simulated gain that varies between 2.47 and 7.73 dB throughout the operating range, and a high simulated efficiency that comes to 98% due to the modifications made to the antenna geometry. The modifications carried out on the antenna are composed of several stages, a circular ring extracted from a circular antenna in which four rings are integrated and, in each ring, four other rings are integrated with a reduction factor of 3/8. To further improve the adaptation of the antenna, a modification of the shape of the ground plane is carried out. In order to test the simulation results, the prototype of the suggested patch was built and tested. The measurement results validate the suggested dual ultra-wideband antenna design approach, which demonstrates good compliance with the simulation. From the measured results, the suggested antenna with a compact volume of 40 × 24.5 × 1.6 mm3 asserts ultra-wideband operation with a measured impedance bandwidth of 7.33 GHz. A high measured efficiency of 92% and a measured gain of 6.52 dB is also achieved. The suggested UWB can effectively cover several wireless applications such as WLAN, WiMAX, and C and X bands.

Sugar Molecules Detection via C2N Transistor-Based Sensor: First Principles Modeling.

Real-time detection of sugar molecules is critical for preventing and monitoring diabetes and for food quality evaluation. In this article, a field effect transistor (FET) based on two-dimensional nitrogenated holey graphene (C2N) was designed, developed, and tested to identify the sugar molecules including xylose, fructose, and glucose. Both density functional theory and non-equilibrium Green's function (DFT + NEGF) were used to study the designed device. Several electronic characteristics were studied, including work function, density of states, electrical current, and transmission spectrum. The proposed sensor is made of a pair of gold electrodes joint through a channel of C2N and a gate was placed underneath the channel. The C2N monolayer distinctive characteristics are promising for glucose sensors to detect blood sugar and for sugar molecules sensors to evaluate food quality. The electronic transport characteristics of the sensor resulted in a unique signature for each of the sugar molecules. This proposed work suggests that the developed C2N transistor-based sensor could detect sugar molecules with high accuracy.

A crossed-polarized four port MIMO antenna for UWB communication.

This paper presents a compact, crossed-polarized, ultra-wideband (UWB) four-ports multiple-input-multiple-output (MIMO) printed antenna. The proposed antenna is constructed from four microstrip circular patch elements fed by a 50-Ω microstrip line. Two metamaterial cell elements, in the form of a rectangular concentric double split ring resonator (SRR), are placed at the upper plane of the substrates for bandwidth improvement and isolation enhancement. The ultra-wideband frequency response is achieved using a defective ground plane. Surface current flow between the antenna's four elements is limited to ensure maximum isolation. The four-port MIMO system is designed with orthogonal antenna elements orientation on an FR4 substrate with a loss tangent of 0.02 and an overall size of 30 mm × 30 mm × 1.6 mm. Such orientation resulted in less than -17dB port-to-port isolation and an impedance bandwidth of 148% (3.1-12 GHz). The proposed UWB-MIMO antenna achieved a maximum realized gain of 6.2dBi with an efficiency of 87%. The measured and simulated results are in good agreement over the operating frequency band (3.1-12 GHz). The results also provide overall good diversity performance with the TARC < -10 dB, ECC < 0.001, DG > 9.9, MEG < -3 dB and CCL <0.1. The proposed antenna is well-suited for applications in WLAN, WIMAX and GPRs.