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In modern communication systems, ultra-wideband (UWB) technology has garnered substantial attention due to its superior attributes compared to traditional narrowband communication systems. Over the past decade, UWB technology has also found applications in microwave-based imaging systems. This study introduces a simple planar coplanar waveguide-fed circular shape arc slot antenna designed specifically for biomedicine and microwave medical imaging applications. The proposed design is implemented on a 1.6-mm-thick FR4 substrate with a relative permittivity of 4.4 and a loss tangent of 0.0009. The antenna has physical dimensions of 26 mm × 29 mm and achieves an impressive bandwidth of 16.6 GHz, spanning 2.4 to 19 GHz. It exhibits a peak gain of 2.5 dBi and consistent omnidirectional radiation characteristics. Thorough temporal analysis validates the antenna's performance within acceptable limits, which is further affirmed through practical fabrication and testing, demonstrating strong agreement with simulation results. [ABSTRACT FROM AUTHOR]

This paper presents a low-insertion-loss open-loop resonator (OLR)-based microstrip diplexer with high-selective for wireless applications. We used two series capacitive gaps in the microstrip transmission line, loaded with rectangular-shaped half-wavelength OLRs, to create a high-selectivity bandpass filter (BPF). The planned BPFs are linked through a T-junction combiner, precisely tuned to align with both filters and the antenna port in order to produce the proposed diplexer. The system is implemented on a rogers TMM4 substrate with a loss tangent of 0.002, a dielectric constant of 4.7, and a thickness of 1.52 mm. The suggested diplexer has dimensions of (90×70) mm². It achieves a modest frequency space ratio of R=0.1646 in both transmit and receive modes by having two resonance frequencies of ft=2.191 GHz and fr=2.584 GHz, respectively. The simulated structure displays good insertion losses of approximately 1.2 dB and 1.79 dB for the two channels, respectively, at fractional bandwidths of 1.24% at 2.191 GHz and 0.636% at 2.584 GHz. The simulated isolation values for 2.191 GHz and 2.584 GHz are 53.3 dB and 66.5 dB, respectively. [ABSTRACT FROM AUTHOR]

This paper introduces the configuration of a microstrip antenna array with a new Archimedean spiral sequential feed network (SSFN) for the upper half of the C-band application. The Archimedean SSFN mechanism uses four circular patch elements to structure the proposed antenna array. The optimized reflection loss (S11) of the proposed SSFN mechanism was obtained by tuning the dimensions of each transformer and then connected with an antenna array. Aiming to make the suggested antenna array compact in size, bending feed lines were utilized. The antenna array is designed with the overall physical dimensions of 75 mm × 75 mm × 1.575 mm, with an electrical size of 1.85λo mm, 1.85λo mm, 0.038λo at a frequency of 7.43 GHz. An equivalent circuit model (ECM) is designed and analyzed to verify the proposed Archimedean SSFN and the designed antenna array. Reflection losses of SSFN and microstrip spiral antenna array (SAA) were confirmed with the suggested circuit model utilizing Computer Simulation Technology (CST) Microwave Studio and Applied Wave Research (AWR) Microwave Office software. According to the empirical results, the SAA has a reflection loss bandwidth of 2.08 GHz (6.15-8.23 GHz) and a maximum gain of 10.2 dBi at 7.43 GHz. The axial ratio (AR) of the proposed antenna covers a bandwidth of 1.6 GHz (6.2-7.8 GHz), which is approximately 22.85% of the entire bandwidth. These results demonstrate a perfect agreement between the simulated and measured outcomes, making the suggested SAA suitable for the C-band wireless application. [ABSTRACT FROM AUTHOR]

This paper proposes a UHF-band microwave sensor for solid material detection based on a tweaking electric field coupled (ELC) resonator. The microwave sensor operates at a low resonant frequency of 0.82 GHz to characterize solid materials with a permittivity range of 1-9.8. The location of the sensing area is determined based on the surface of the resonator with the highest electric field. The permittivity of the sample is determined based on perturbation theory by observing the frequency shift relative to changes in the permittivity of the sample placed in the sensing area of the proposed sensor. From the measurement process, the proposed sensor has a normalized sensitivity (NS) of 1.49%, frequency detection resolution (FDR) of 0.012 GHz, and an average accuracy of 96.72%. This work has a significant contribution and can be recommended for several applications including the pharmaceutical, biomedical, and materials industries. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a high-selectivity, low-insertion-loss open-loop resonator (OLR)-based microstrip diplexer designed for wireless communication systems. We employed a microstrip transmission line with two serial capacitive gaps, incorporating rectangular half-wavelength open-loop resonators, to create a bandpass filter (BPF) with remarkable selectivity. The intended BPFs are interconnected by a T-junction combiner, which is matched to both filters and the antenna port, thereby creating the modelled diplexer. The system is implemented on a Rogers TMM4 substrate featuring a loss tangent of 0.002, a dielectric constant of 4.7, and a thickness of 1.52 mm. The suggested diplexer has dimensions of (90×70) mm². It achieves a modest frequency spacing ratio of R=0.1646 in both transmit and receive modes, with resonance frequencies of ft = 2.191 GHz and fr = 2.584 GHz, respectively. The simulated structure demonstrates favorable insertion losses of approximately 1.2 dB and 1.79 dB for the two channels at fractional bandwidths of 1.24% (2.191 GHz) and 0.636% (2.584 GHz). The simulated isolation values at 2.191 GHz and 2.584 GHz are 53.3 dB and 66.5 dB, respectively. Notably, the simulated and measured results exhibit a high degree of consistency. However, minor variations between the simulated and actual results have been noted, primarily attributable to the inherent fabrication tolerances. [ABSTRACT FROM AUTHOR]

This paper proposes a MIMO circular patch microstrip antenna (CPMA) operating at resonant frequencies of 3.5 GHz and 6 GHz for 5G communication systems. The proposed antenna is designed using RO-5880 substrate with a dielectric constant (e) of 2.2, a thickness (h) of 1.58 mm and a loss tan (tand) of 0.0009. The dual band characteristic is obtained by placing the slot in the center of the CPMA while the inset feeder is used to control the reflection coefficient. Furthermore, mutual coupling reduction is obtained by controlling the distance between the antennas when configured in MIMO. Based on the simulation results, the proposed antenna produces excellent performance with reflection coefficient ≤ - 10 dB and mutual coupling (MC) ≤ 20 dB at resonant frequencies of 3.5 GHz and 6 GHz. This research is very useful and can be recommended as a receiving antenna for 5G communication system. [ABSTRACT FROM AUTHOR]

In the area of wearable technology an enhancement of basic microstrip antenna is evolution of wearable textile antenna. A new development of wearable antenna is the incorporated of conductive plane using nanocomposite ink that embedded onto the fabric. In this paper, the performance of variety thickness of conductive Graphene-Ag-Cu ink on a drill fabric is presented. The performances include its resistivity and conductivity measurement. By performing a measurement using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and four-point probe, it can obtain and measure the composition and thickness of nanocomposite layered on a fabric and resistivity respectively. Hence, it can provide detailed information about the surface morphology, roughness, and thickness of the nanocomposite coating on the fabric as well as the electrical conductivity. Finally, the electrical conductivity increased to the fifth layered from 0.1473×104 S/cm up to 0.5393×104 S/cm. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper introduces a method to enhance the gain of ultra-wideband (UWB) planar antennas by employing a grounded frequency-selective surface (FSS) as a reflector. The grounded FSS reflector comprises square patch structures (SPSs) of unit cells with a complete ground plane. The designed FSS utilizes miniaturized unit cells that are printed on both sides of an FR4 substrate, making it highly suitable for a wide range of applications, particularly as a reflector to optimize the gain of UWB omnidirectional radiators. This concept is demonstrated by employing a circular monopole UWB antenna as the radiator. The measured outcomes of the suggested antenna with the grounded FSS maintain a broad frequency range of bandwidth of 9.162 GHz, spanning from 2.638 GHz to 11.8 GHz. The antenna, in combination with the FSS, achieves a significant measured gain of 7.6 dBi and a high efficiency of 93% at 9.6 GHz. The attributes of the suggested UWB FSS make it an ideal solution for seamless combining with small-sized broadband circuits, thereby maximizing its effectiveness. [ABSTRACT FROM AUTHOR]

This paper proposes a MIMO circular patch microstrip antenna (CPMA) operating at resonant frequencies of 3.5 GHz and 6 GHz for 5G communication systems. The proposed antenna is designed using RO-5880 substrate with a dielectric constant (εr) of 2.2, a thickness (h) of 1.58 mm and a loss tan (tan δ) of 0.0009. The dual band characteristic is obtained by placing the slot in the center of the CPMA while the inset feeder is used to control the reflection coefficient. Furthermore, mutual coupling reduction is obtained by controlling the distance between the antennas when configured in MIMO. Based on the simulation results, the proposed antenna produces excellent performance with reflection coefficient ≤ – 10 dB and mutual coupling (MC) ≤ – 20 dB at resonant frequencies of 3.5 GHz and 6 GHz. This research is very useful and can be recommended as a receiving antenna for 5G communication system. [ABSTRACT FROM AUTHOR]