Compact Size And High Gain Of CPW-Fed UWB Strawberry Artistic Shaped Printed Monopole Antennas Using FSS Single Layer Reflector

This study proposed the use of coplanar waveguide Ultrawide-band strawberry artistic shaped printed monopole (SAPM) antenna with a single-layer frequency selective surface (FSS) as the metallic plate to improve the gain of antenna application. The intersection of six cylinders is used to structure the strawberry artistic shaped radiating element, which leads to enhancing the antenna bandwidth. The proposed FSS reflectors used a 10 × 10 array with the unit cell of 6mm × 6mm in introducing a center-operating frequency. This study used the FR4 substrate with coplanar waveguide (CPW) fed to print the proposed antenna, which provided a wide impedance bandwidth of 8.85 GHz (3.05–11.9GHz) that covers the licensed Ultrawide-band. The proposed FSS transmitted a stop-band transmission coefficient, which is below −10 dB with the linear reflection phase over the bandwidth in the range from 3.05 GHz to 11.9 GHz. The UWB SAPM antenna with FSS reflector showed an improvement from 1.65 dB to 7.87 dB in the lower band and 6.3 dB to 9.68 dB in the upper band with an enhancement of 6.22 dB. The gain value is enhanced by the gaping between the antenna and FSS, which has an approximately constant gain response through the band, the gain is sustained among 7.87 dB to 9.68 dB. The total dimension of the antenna is 61mm×61mm×1.6 mm. The proposed antenna structure provides the directional and balanced far-field pattern, which is suitable for Ultrawide-band (UWB) applications and ground-penetrating radar (GPR) application

Development Of A DC To DC Buck Converter For Photovoltaic Application Utilizing Peripheral Interface Controller

Nowadays, renewable energy has become one of the important energy resources in our daily lives. One of the important and promising renewable energy resource today is the photovoltaic (PV). However, weather changes contribute to the PV output power fluctuations. Thus, for a PV-related system, a closed-loop control system is necessary for ensuring the system produces a regulated dc output voltage. This paper presents the development of PIC16F877A microcontroller-based dc to dc buck converter. This converter steps down a dc voltage source to a specific voltage which suitable for other specific applications. For the PV output voltage fluctuating from 18V to 12V, the microcontroller generates a pulse-width modulation (PWM) signal accordingly to control the converter switching device MOSFET IRF540, thus regulating the converter output voltage to 12V. The system simulation was carried out in the PROTEUS ISIS Professional software tool. Due to the unavailability of the PV device in this simulation software, a dc voltage source is utilized. This voltage source is varied to emulate the PV output variations. The simulation results show that the controller managed to step-down the voltage source and regulated at 11.98Vdc. The prototype was built and tested in a laboratory for validation. Due to the constrains and limitations of the PV module, an adjustable power supply was used to provide variation of input voltage levels for the buck converter. The experiment results also show that the output voltage is managed to be regulated at 12V. The results signify the efficacy of developed converter control system algorithm

Design Of A Wideband Strip Helical Antenna For 5G Applications

This paper presents the design of wideband strip helical antenna for 5G Application. The strip helical antenna is designed for 5G and wideband applications that provide a wide bandwidth and circular polarization. The helical antenna is planned on at 5.8 GHz frequency by using Teflon material. The new designed strip is printed on a substrate then rolled into a helix shape to achieve circular polarization without an impedance matching and that the proposed antenna can be used for potential applications in wideband wireless communication. A wideband bandwidth of 2.41 GHz with a resonant frequency at 5.8 GHz is achieved by the helical antenna on the Teflon substrate. The presented antenna on Teflon substrate has achieved a gain of 11.2 dB. The antenna design parameters and the simulated results are achieved using the commercial software CST. The proposed antenna can be used for various wireless applications such as Wideband, Ultra wideband, 5G and wireless Applications

High gain of UWB planar antenna utilising FSS reflector for UWB applications

In this paper, a high gain and directional coplanar waveguide (CPW)- fed ultra-wideband (UWB) planar antenna with a new frequency selective surface (FSS) unit cells design is proposed for UWB applications. The proposed UWB antenna was designed based on the Mercedes artistic-shaped planar (MAP) antenna. The antenna consisted of a circular ring embedded with three straight legs for antenna impedance bandwidth improvement. The modelled FSS used the integration of a two parallel conductive metallic patch with a circular loop structure. The FSS provided a UWB stopband filter response covering a bandwidth of 10.5 GHz, for frequencies from 2.2 to 12.7 GHz. The proposed FSS had a compact physical dimension of 5 mm × 5 mm × 1.6 mm, with a printed array of 19 × 19 FSS unit cells. The FSS unit cells were printed on only one side of the dielectric FR4 substrate and placed as a sandwich between the antenna and the reflector ground plane. An equivalent circuit configuration (ECC) was used to verify the FSS unit cell structure’s performance. The simulated results indicated that the UWB MAP antenna and FSS reflector provided a fractional bandwidth of 136% and a high gain of 11.5 dB at 8.5 GHz with an acceptable radiation efficiency of 89%. Furthermore, the gain was improved across the operating band and kept between 8.3 and 11.5 dB. The proposed antenna was in good agreement between theoretical and experimental results and offered a wide enough bandwidth for UWB and vehicle applications

New CPW-Fed Broadband Circularly Polarized Planar Monopole Antenna Based On A Couple Of Linked Symmetric Square Patches

A new broadband circularly polarized planar monopole antenna with coplanar waveguide feeding (CPW-fed) is proposed. This antenna consists of a couple of linked symmetric square patches (CLSSP), an asymmetric ground plane and two strips connected to the left ground plane by the CLSSP radiator and a straight strip. A broad impedance bandwidth (IBW) is achieved. Moreover, a broad axial ratio bandwidth (ARBW) is obtained by using an asymmetric ground plane and an inverted L-shaped strip. Simulation results demonstrate that IBW reaches 119% (1.56-6.18 GHz) and ARBW is 88.9% (2-5.2 GHz). The latter is completely overlapped by the simulated IBW. In addition, antenna performance is investigated by studying different parameters

Compact CPW-Fed Broadband Circularly Polarized Monopole Antenna With Inverted L-Shaped Strip And Asymmetric Ground Plane

The design of a coplanar waveguide-fed (CPW-fed) broadband circularly polarized printed monopole antenna is proposed. The antenna consists of a simple rectangular radiator monopole, an inverted L-shaped strip, a horizontal stub, and a modified asymmetric ground plane. Simulation results indicate that the impedance bandwidth (IBW) is 121% (1.575-6.4 GHz), and the axial ratio bandwidth (ARBW) is 64.3% (2.85-5.55 GHz). A parametric study is performed for verification. Results: indicate that the proposed antenna is suitable for different wireless communications systems

Design Of Helical Antenna For Next Generation Wireless Communication

This study proposes a novel helical antenna design for next generation applications. The strip helical antenna is prescribed for next generation wireless communication and wideband applications that offer circular polarization and a wide bandwidth. In fact, the proposed helical antenna suits 5.8 GHz frequency by using Teflon material. The newly-designed strip was printed on a substrate and rolled into a helix shape to achieve circular polarization without impedance matching. This antenna is meant for wideband wireless communication applications. A wide bandwidth of 2.7 GHz with 5.8 GHz resonant frequency was attained through the use of helical antenna on Teflon substrate. The proposed antenna on Teflon substrate recorded a gain of 8.97 dB and 92% efficiency. The antenna design parameters and the simulated results were retrieved using Computer Simulation Technology software (CST). The measurement result of return loss displayed mismatch at 5.22 GHz due to manual fabrication. This developed antenna may be applied for a number of wireless applications, including Wideband, Ultra-wideband, and 5G

A review of hybrid couplers: State-of-the-art, applications, design issues and challenges

In recent years, the hybrid branch-line coupler has attracted much attention due to its appealing features such as of low cost and ease in fabrication for wireless communications. The fifth-generation cellular networks promise to support several wireless technologies by capitalizing a multitude of frequencies and increase data rates. To achieve that, the butler matrix technique can be used to enhance both bandwidth and data rate with the implementation of beamforming. Conventional hybrid couplers are the main component to build a butler matrix, but they are generally bulky in size and narrow in bandwidth. Moreover, requirements imposed by newer wireless technologies makes the efforts in improving size compactness and bandwidth even more challenging. On the other hand, several techniques have been proposed in literature to solve both issues. This study focuses on the design challenges and issues of hybrid coupler designs and technologies, besides underlining their promising potential. In this context, several techniques for hybrid coupler to achieve the required bandwidth and size reduction are highlighted, such as the T-shape, meander line, two sections, three-section, and parallel couple lines

A Miniaturised UWB FSS With Stop-Band Characteristics For EM Shielding Applications

This paper aims to present a miniaturised and new design of ultra-wideband (UWB) frequency selective surface (FSS) with stopband characteristics for electromagnetic (EM) shielding applications. The modelled FSS used the integration of a two parallel conductive metallic patch with a circular loop structure. The FSS provided a UWB stopband filter response covering a bandwidth of 10.5 GHz, for frequencies from 2.2 GHz to 12.7 GHz. The proposed FSS had a compact physical dimension of 5 mm × 5 mm × 1.6 mm, with a printed array of 19 × 19 FSS unit cells. An equivalent circuit configuration (ECC) was used to verify the FSS unit cell structure’s performance. The proposed FSS was identified to contribute towards independent polarisation for obliques incidences transverse electric (TE) and transverse magnetic (TM) polarisations from 0° to 20°. Besides, the performance of the proposed FSS is stable over a wide range of incident angles for TE and TM polarisation

A Compact UWB FSS Single Layer With Stopband Properties For Shielding Applications

A compact and simple structure of ultra-wideband (UWB) frequency selective surface (FSS) single layer was formed to obtain stopband characteristics in this study. The proposed FSS is made of a modified square loop (MSL) structure with an electrical size of 0.15λ0 ×0.15λ0 × 0.041λ0 and is printed on a single side of the dielectric FR4 substrate. To determine the FSS unit cell structure’s behaviour, an equivalent circuit model (ECM) was introduced. Based on the observations, the designed FSS achieved a bandwidth of 10GHz (2.6-12.6 GHz) with -10dB of return loss performance. Hence, the proposed FSS was identified to contribute towards stable angular stability for transverse electric (TE) and transverse magnetic (TM) polarisations from 0° to 45°. Overall, the simulated results were in high-grade harmony compared to the measured result