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A printed Bow-Tie slot antenna with loaded stub is proposed and the effects of changing the dimensions of the slot area, the stub and load sizes are considered in this paper. These parameters have a considerable effect on the antenna characteristics as well as its performance. An in-depth parametric study of these dimensions is presented. This paper proposes the necessary conditions for initial approximation of dimensions needed to design this antenna. In order to achieve the desired performance of the antenna fine tuning of all sizes of these parameters is required. The parametric studies used in this paper provide proper trends for initiation and tuning the design. A prototype of the antenna for 1.7GHz to 2.6GHz band is fabricated. Measurements conducted verify that the designed antenna has wideband characteristics with 50% bandwidth around the center frequency of 2.1GHz. Conducted measurements for reflection coefficient (S11) and radiation pattern also validate our simulation results.

This study proposed the dimensions of 55 mm × 34 mm × 1 mm for wearable antenna; the copper Y-slot patch and copper partial ground are attached to a felt substrate. The partial ground has the higher impact in antenna gain enhancement compared with the full ground, making it the most suitable candidate for wearable applications and suitable for embedding in fabrics for use in medical applications. In addition, the proposed antenna design combined a fabric–metal barrier operated at 2.4 GHz 65.4% with a low specific absorption rate (SAR) of 0.01 watts per kilogramme (W/kg) and 0.006 W/kg per 10 g and a gain of 6.48 dBi. The proposed antenna has an omnidirectional radiation pattern. The two-layer barrier is designed to achieve high electromagnetic (EM) absorption and reduce the antenna’s absorption coefficient (SAR) for safe use in applications involving human activities. Simulation and measurement results on the arm and the head of the human body indicated that the antenna has excellent performance. In addition, the measurement results agreed well with the simulation results, making the proposed wearable antenna reliable for medical and 5G applications.

Since antennas are strong radar targets, their radar cross section (RCS) reduction and radiation enhancement is of utmost necessity, particularly for stealth platforms. This work proposes the design of a Fabry–Perot Cavity (FPC) antenna which has wideband low monostatic RCS. While in the transmission mode, not only is gain enhancement achieved, but radiation beam is also deflected in the elevation plane. Moreover, the design is low-profile, i.e., the cavity height is ~λ/4. A patch antenna designed at 6 GHz serves as the excitation source of the cavity constructed between the metallic ground plane and superstrate. The superstrate structure is formed with absorptive frequency selective surface (AFSS) in conjunction with dual-sided partially reflective surface (PRS). Resistor loaded metallic rings serve as the AFSS, while PRS is constructed from inductive gradated mesh structure on one side to realize phase gradient for beam deflection; the other side has fixed capacitive elements. Results show that wideband RCS reduction was achieved from 4–16 GHz, with average RCS reduction of about 8.5 dB over the reference patch antenna. Off-broadside peak radiation at −38° was achieved, with gain approaching ~9.4 dB. Simulation and measurement results are presented.

Inerter is a recent element in suspension systems with the property that the generated force is proportional to the relative acceleration between its two terminals, which is similar to the way a spring reacts to relative displacement and a damper to relative velocity. This paper presents the analysis of a non-linear inerter working in parallel to passive spring and damper of a vehicle suspension to evaluate its effect on vehicles ride. The non-linear inerter was theoretically capable of switching between on and off states depending on whether or not the suspension deflection was beyond a specified free play. In the study, this behavior was represented mathematically as control law which depended on the relative displacement between the sprung and unsprung masses. A mathematical quarter vehicle model incorporating the non-linear inerter was simulated in MATLAB/Simulink to determine the vehicle responses due to road input in the form of step profile for different combinations of free play and inerters on-state proportionality constant called the inertance. Results showed improvements in vehicle ride comfort, as demonstrated by the lower root-mean-squared sprung mass accelerations compared to the ordinary passive suspension with only spring and damper. Additionally, implementation of non-linear inerter gave lower percentage overshoot to step input, indicating better transient response than ordinary passive suspension.

In this paper, a new compact wideband monopole antenna is presented for wireless communication applications. This antenna comprises of a new radiating patch, a new arc-shaped strip, microstrip feed line, and a notched ground plane. The proposed radiating patch is combined with a rectangular and semi-circular patch and is integrated with a partial ground plane to provide a wide impedance bandwidth. The new arc-shaped strip between the radiating patch and microstrip feed line creates an extra surface on the patch, which helps further widen the bandwidth. Inserting one step notch on the ground plane further enhances the bandwidth. The antenna has a compact size of 16×20×1.6mm3. The measured result indicated that the antenna achieves a 127% bandwidth at VSWR≤2, ranging from 4.9GHz to 22.1GHz. Stable radiation patterns with acceptable gain are achieved. Also, a measured bandwidth of 107.7% at VSWR≤1.5 (5.1-17GHz) is obtained, which is suitable for UWB outdoor propagation. This antenna is compatible with a good number of wireless standards, including UWB band, Wimax 5.4 GHz band, MVDDS (12.2-12.7GHz), and close range radar and satellite communication in the X-band (8-12GHz), and Ku band (12-18GHz).

The increasing usage of wireless technology has prompted the development of a new generation antenna compatible with the latest devices, with on-body antennas (wearable antennas) being one of the revolutionary applications. This modern design is relevant in technologies that require close human body contact, such as telemedicine and identification systems, due to its superior performance compared to normal antennas. Some of its finer characteristics include flexibility, reflection coefficient, bandwidth, directivity, gain, radiation, specific absorption rate (SAR), and efficiency that are anticipated to be influenced by the coupling and absorption by the human body tissues. Furthermore, improvements like band-gap structure and artificial magnetic conductors (AMC) and (DGS) are included in the wearable antenna that offers a high degree of isolation from the human body and significantly reduces SAR. In this paper, the development of on-body antennas and how they are affected by the human body were reviewed. Additionally, parameters that affect the performance of this new antenna model, such as materials and common technologies, are included as an auxiliary study for researchers to determine the factors affecting the performance of the wearable antenna and the access to a highly efficient antenna.

Ablution area is one of the facilities used by most Muslims in all categories. There are numbers of design guidelines for praying facilities but lack on ablution area specification. Therefore, this study was conducted to design an ergonomic ablution area for the M uslim's disabled and elderly based on their preferences and anthropometric dimension. Kano questionnaires and user evaluation form, was used to investigate the preferences of elderly and dis abled in ablution area to 20 respondents at Masjid Bulat, Petaling Jaya and Masjid Kampung Kerinchi,Pantai Dalam, Kuala Lumpur in 2015. Anthropometric dimension of elderly and disabled people was measured. Besides, dimensions of two existing ablution units at selected mosques were evaluated using \"Ablution Unit Dimension Eval uation' form. New ablution area design was developed based on elderly and disabled people anthropometric dimension and user preferences as well as user satisfaction survey. This study can be considered as preliminary study for the d evelopment of ergonomic ablution unit design. It is hoped that the findings and recommendations from this research will be referred by the stakehol ders to determine the best solution to increase the level of comfort and accessibility for elderly and disable d at mosques in M alaysia.

Communication with low radar signature platforms requires antennas with low backscatter, to uphold the low observability attribute of the platforms. In this work, we present the design for a Fabry–Perot (F-P) cavity antenna with low monostatic radar cross section (RCS) and enhanced gain. In addition, peak radiation is tilted inthe elevation plane. This is achieved by incorporating phase gradient metasurface (PGM) with absorptive frequency selective surface (FSS). The periodic surface of metallic square loops with lumped resistors forms the absorptive surface, placed on top of a partially reflecting surface (PRS) with an intervening air gap. The double-sided PRS consists of uniform metallic patches etched in a periodic fashion on its upper side. The bottom surface consists of variable-sized metallic patches, to realize phase gradient. The superstrate assembly is placed at about half free space wavelength above the patch antenna resonating at 6.6 GHz. The antenna’s ground plane and PRS together construct the F-P cavity. A peak gain of 11.5 dBi is achieved at 13° tilt of the elevation plane. Wideband RCS reduction is achieved, spanning 5.6–16 GHz, for x- and y-polarizations of normally incident plane wave. The average RCS reduction is 13 dB. Simulation results with experimental verifications are presented.

Figure 1 shows the simulated dimensions and the fabricated first-pass antenna using a dielectric constant of 4.6 at 10 MHz, per the datasheet. The simulation (see Figure 2) predicts resonance at 1.63 GHz. The difference in resonant frequency between measurement (1.864 GHz) and simulation is clearly apparent.

Modern electronic devices and medical equipments such as computers, magnetic resonance imaging (MRI) machines and scanning electron microscopes (SEM) may not be able to operate efficiently if the items were continuously exposed under extremely low frequency a.c magnetic field emissions. This effect usually is due to the phenomenon of electromagnetic field interference (EMI) which is caused by high voltage sources. Recent study in Malaysia has indicated that applications with passive material shielding techniques were among the best options but it may be costly. In order to reduce the cost, passive shielding materials from recycling local steel mill by-product were used. The materials performances were evaluated through induction magnetic field measurement instrumentation methods with typical EMF Helmholtz a.c single-phase coil excitation test systems. The experiment was successfully conducted with achievable 35.5% reduction rate of magnetic field emissions from material specimens for effective shielding schemes. [PUBLICATION ABSTRACT]