Dependence of the Xe flash lamps’ UV radiation efficiency on the volumetric power density of the discharge

The study results of the peak and average electrical volumetric power density influence on the radiation efficiency and brightness temperature in the 200–300 nm bactericidal spectrum range are presented. A linear dependence of the radiation efficiency change in the 5.1–8.4 % range was obtained with the average volumetric power density increase from 177 to 390 kW/cm3. The brightness temperature dependence in the specified spectral region on the peak volumetric power density is a logarithmic character with decreasing growth rate when approaching 9 kK. This effect can be associated with both radiation blocking by vaporized quartz fumes and with UV light shielding by outer plasma layers

Design and Study of an mmWave Wearable Textile Based Compact Antenna for Healthcare Applications

In this study, the design of a compact and novel millimeter wave cotton textile-based wearable antenna for body-centric communications in healthcare applications is presented. The free space and on-body antenna performance parameters for the proposed antenna at 60 GHz are investigated and analyzed. The antenna is based on a 1.5 mm thick cotton substrate and has an overall dimension of 7.0 × 4.5 × 1.5 mm3. In free space, the antenna is resonant at 60 GHz and achieves a wide impedance bandwidth. The maximum gain at this resonant frequency is 6.74 dBi, and the radiation efficiency is 93.30%. Parametric changes were carried out to study the changes in the resonant frequency, gain, and radiation efficiency. For body-centric communications, the antenna was simulated at 5 different distances from a three-layer human torso-equivalent phantom. The radiation efficiency dropped by 24% and gradually increased with the gap distance. The antenna design was also analyzed by using 10 different textile substrates for both free space and on-body scenarios. The major benefits of the antenna are discussed as follows. Compared to a previous work, the antenna is very efficient, compact, and has a wide bandwidth. In BCWCs for e-health applications, the antenna needs to be very compact due to the longer battery life, and it has to have a wide bandwidth for high data rate communication. Since the antenna will be wearable with a sensor system, the shape of the antenna needs to be planar, and it is better to design the antenna on a textile substrate for integration into clothes. The antenna also needs to show high gain and efficiency for power-efficient communication. This proposed antenna meets all these criteria, and hence, it will be a good candidate for BCWCs in e-health applications.

A Compact Disc Shaped Microstrip Patch Antenna Using Inset Fed at 5GHz for Satellite Communications

This examination work is focused around planning and simulating another kind of inset feed Disc Shaped Microstrip Patch Antenna (DSMPA) with Inset feed and Defected ground plane (DGP). By presenting a round space at the focal point of the ground plane, improved attributes of Microstrip patch antenna can be accomplished. The proposed Disc Shaped Microstrip patch antenna is reverberating at 5 GHz. Simulation has been finished by utilizing reenactment programming HFSS version15. From recreation results, it discovers that our examined Disc Shaped Microstrip patch antenna yields better return loss of - 25.1 dB & VSWR estimation of 0.96 dB. The examined DSMPA is yielding a higher radiation efficiency of 77.20 %. The minimized size and higher radiation efficiency contrasted with rectangular Microstrip patch antenna makes it all the more generally helpful for satellite communications.

Metamaterial Based Multiband Microstrip Patch Antenna for 5G Wireless Technology-enabled IoT Devices and its applications

In the present era of the digital world, demand for IoT based smart devices has seen tremendous growth. These devices involve real-time human-to-machine communication and interaction. Communication of uninterrupted quality depends on the high bandwidth and speed of the internet. The development of 5G wireless network technology is the response to the crucial factors that lead to this demand, because of its ability to provide extremely fast internet speed, high bandwidth, high performance, reduced latency, and high reliability. In this research work, the authors have developed a metamaterial-based multi-band microstrip rectangular shape patch antenna with a wide high-performance bandwidth because of the demand. The proposed design has a low dielectric constant of 2.2, which is of Rogers RT/Duroid substrate, and a dielectric loss tangent of 0.0010. The design has a resonant frequency of 26 GHz. The simulations carried out using FEKO software has been analyzed for performance. The simulation and analysis reveal a good return loss of -34.4 dB at 26 GHz, -13.49 dB at 40 GHz, -13.63 dB at 53.5 GHz, high bandwidth of 5.368 GHz at 26 GHz, 3.76 GHz at 40 GHz, 2.88 GHz at 53.5 GHz, desirable voltage standing wave ratio, 1⩽VSWR⩽ 2, high gain of 10 dBi at 26 GHz, 5 dBi at 40 GHz, and high antenna radiation efficiency of 99.7 % at 26 GHz, and 61% at 40 GHz, 50% at 53.5 GHz. The bandwidth, return loss, antenna radiation efficiency and power density indicate an improvement of 5.368 GHz to 5.630 GHz, -34.82 dB to -57.10 dB, 99.7 % to 99.8 % and 2208 kW/m2 to 2800 kW/m2 respectively after loading and incorporating artificial magnetic split-ring resonator-based metamaterial on the patch. Further improvement is also seen at other frequencies. The proposed design has immense benefits for humanity due to its improved capacity to manage larger connected IoT devices in the fields of Industrial 4.0, Healthcare 4.0, Autonomous Vehicles, Agriculture 4.0, Education, Climate Change, Sustainability, and Oceanography.

An Estimation Method of an Electrical Equivalent Circuit Considering Acoustic Radiation Efficiency for a Multiple Resonant Transducer

The electrical equivalent model of an underwater acoustic transducer must be exactly defined in the operating frequency band to improve the driving efficiency between a sonar transmitter and a transducer. This paper used the PSO (particle swarm optimization) algorithm to estimate electrical equivalent circuit parameters of a transducer that has multiple resonant modes. The proposed method used a new fitness function to minimize the estimation error between the measured impedance of the transducer and the estimated impedance. The difference to the previous method is that the proposed method considered interference effects of the adjacent resonant modes. Additionally, this paper analyzed the effective power and separated the mechanical and acoustical resistance by considering the acoustic radiation efficiency of the transducer. As a result, the proposed method estimated all parameters at the resonance points which are influenced by the adjacent resonant modes.

A Compact High Gain Multiband Bowtie Slot Antenna with Miniaturized Triangular Shaped Metallic Ground Plane

This paper presents a new compact, high gain and multiband planar bowtie slot antenna. The antenna structure comprises of dielectric substrate, copper conducting sheet, fillet triangular-shaped slots, and a chamfered metallic ground plane. The proposed antenna model is fed with the 50 Ω standard grounded coplanar waveguide (GCPW) feedline. The designed antenna is low profile with compact dimensions of 0.379λ×0.186λ×0.012λ at 2.39 GHz frequency. Stable multi-resonant behavior of frequencies is obtained with the material selection, slots dimensions and position. Moreover, the parametric study has been carried out in order to validate the frequency tuning mechanism and impedance matching control. The novelty of designed antenna lies in high performance features which have been achieved with ultra-compact (0.039λ×0.022λ) modified triangular shaped metallic ground plane. The proposed antenna is fabricated and experimentally verified. The antenna key features in terms of return loss, surface current distribution, peak gain, radiation efficiency and radiation patterns have been analyzed and discussed. The designed radiator exhibits the excellent performance including strong current density, peak realized gain of 6.3 dBi, 95% radiation efficiency, wide fractional bandwidth of 39.5% and good radiation characteristics at in-band frequencies. The simulation and measured results are in good agreement and hence make the proposed antenna a favorable candidate for the advanced heterogeneous wireless communication applications.

A Miniaturized Broadband and High Gain Planar Vivaldi Antenna for Future Wireless Communication Applications

This paper presents a new miniaturized planar Vivaldi antenna (PVA) design. The proposed antenna structure consists of an aperture tapered profile and cavity stub fed with a simple 50 Ω strip line feeding network. The designed PVA offers versatile advantages, including the miniaturized size and simple design, and exhibited an outstanding performance compared to the latest reported literature. The antenna occupies a minimal space with an electrical size of 0.92λ0 × 0.64λ0 × 0.03λ0. The antenna achieves an excellent relative impedance bandwidth 117.25% at 10 dB return loss, peak realized gain of 10.9 dBi, and an excellent radiation efficiency of 95% at the specific resonances. The antenna’s optimal features, that is, broadband, high gain, and radiation efficiency, are achieved with efficient grooves based approach. Besides, the proposed antenna results are also analyzed in the time domain, which shows the excellent group delay performance <2 ns in the operational band. The proposed antenna exhibited a stable far-field radiation pattern in orthogonal planes and strong distribution of current at multiple resonances. Simulation and the measured result show a good agreement. The proposed antenna has achieved optimal performance and is suitable for future wireless communication applications.