Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Dual

A New Compact Dual-band Antenna Based on Sierpinski Curve Slotted Ground Plane and Current Distribution Analysis

M.T. Yassen

Engineering and Technology Journal, 2017, Volume 35, Issue 4, Pages 406-410

A new design approach has been used to achieve a dual band response from a multi-band resonance. The design approach is wholly depending on current distribution analysis on the surface of a multi-band antenna. The proposed multi-band antenna consists of a slotted ground plane with a simple 50-ohm microstrip feed line on the other side of an FR4 substrate having 4.4 relative dielectric constant and 1.6 mm thickness. The geometry of the first iteration Sierpinski curve fractal has been employed to the slotted ground plane antenna structure. Two small squares have been inserted to both internal upper corners of the slotted ground plane as a technique to control the path of electrical current on the surface of the multi-band antenna. With this technique, the resulted antenna can offer two resonating bands with respect to -10 dB S11. The first band (2.28-2.6) GHz, while the second band (5-5.58) GHz. The proposed antennas have been modeled and simulated using two softwares (CST Microwave Studio and High-Frequency Structure Simulation HFSS) to verify the results of both antennas and the other antenna parameters have been studied by using CST only.

A Cantor Fractal Based Printed Monopole Antenna for Dual-band Wireless Applications

Mohammed R. Hussan

Engineering and Technology Journal, 2016, Volume 34, Issue 7, Pages 1347-1359

Cantor fractal geometry and its variants are found attractive for microwave antenna designers seeking for compact size multiband antennas. This paper presents the design of a new microstrip fed printed monopole antenna for use in dual-band wireless applications. The radiatingelement of the monopole antenna is in the form of Cantor fractal geometry of the second iteration as applied on rectangular patch. The monopole radiating element has been etched on a substrate with relative permittivity of 4.4 and 1.6 mm thickness and is fed with a 50 ohm microstrip line. A reduced ground plane has been etched on the reverse side of the substrate. Modeling and performance evaluation of the proposed antenna have been carried out using the commercially available EM simulator, IE3D. Simulation results reveal that the proposed antenna offers dual-band resonant behavior with –10 dB impedance bandwidths and radiation characteristics suitable for almost most of the recently available services in the 1-6 GHz range. A parametric study has been carried out to explore the effect the aspect ratio of the proposed antenna radiating element on its performance. The study reveals that the radiating element aspect ratio has a considerable effect on the coupling of the two resonant bands. Besides the simple design, the antenna offers reasonable radiation characteristics. Simulated–10 dB impedance bandwidths for the lower and the upper resonant bands are (2.30–2.84 GHz) and (5.56–6.01 GHz) respectively. This makes the proposed antenna suitable to cover numbers of operating bands of the wireless communication systems (2.4 GHz-Bluetooth, 2.4 GHz ISM, 2.5/5.8 GHz-WLAN, 5.8 GHz-ITS).

Study the Performance of a Domestic Refrigerator with Dual-Loop Cycle Flow Condenser and Comparison with Wire-on-Tube Condenser

Dheya Ghanim Mutasher

Engineering and Technology Journal, 2016, Volume 34, Issue 3, Pages 578-587

This paper presents an experimentalinvestigation into the performance of domestic refrigerator system with two different types of condensers, novel design of dual-loop condenser and the conventional condenser.The geometrical configuration considered in this study is representative designing and manufacturing of novel type of dual-loop cycle condenser and compared with typical condenser. The experimentswere conducted with a refrigerator designed to work with HFC134a, under no load and with different loads as (1.5, 3 and 12 litters of water).The results showed that the dual-loop condenser decreases the work done by the compressor by about (1.951% to 5.257%). Also, the effects of shape change of the condenser can be reducing the pressure drop as result of reduction the frictional losswhere can rotate the flow without restriction to the flow in the dual-loop condenser

A New Narrow Band Dual-Mode Miniaturized Bandpass Filter Design for Wireless Communication Systems

Nasr N Hussain; Jawad K. Ali

Engineering and Technology Journal, 2009, Volume 27, Issue 10, Pages 1937-1951

A new narrowband, compact, and low profile microstrip filter design is
presented in this paper as a candidate for use in modern wireless systems. The proposed design is based on the use of fractal multiple ring resonator. Multiple ring resonators have advantages to possess much narrower and shaper performance responses than those of the single ring resonator. The proposed filter design is fractally generated using Minkowski-Like Pre-Fractal curve geometry applied to the conventional square microstrip square ring filter. Filter structures resulting from the successive iterations in the fractal generation process show a
considerable size reduction compared with the conventional microstrip square ring filter designed at the same frequency using the same substrate material. The performance of the generated bandpass filter structures have been analyzed using method of moments (MoM) based software package Microwave Office 2007. Performance Simulation results show that filter structures employing 2nd and 3rd iterations offer size reduction percentages of about 61.5% and 77.7% respectively
as compared with the conventional square ring filter