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Ojaroudi N.,Islamic Azad University at Ardabil
Microwave and Optical Technology Letters | Year: 2014

In this article, a novel small monopole antenna with dual band-notched characteristic for ultrawideband applications is proposed. The proposed antenna consists of circular-disc radiating patch with a rotated T-shaped slit, a feed line with a rotated Ω-shaped split-ring resonator, and a ground plane. The designed antenna has a small size. The simulated and measured results show that the antenna design exhibits an operating bandwidth (VSWR<2) from 2.86 to 12.92 GHz with 3.3-4.2 and 5-6 GHz rejected bands covering all the 5.2/5.8 GHz wireless local area network, 3.5/5.5 GHz worldwide interoperability microwave access, and 4 GHz C bands. Good antenna gain and radiation pattern characteristics are obtained in the frequency band of interest. © 2014 Wiley Periodicals, Inc. Source

Ojaroudi N.,Islamic Azad University | Ojaroudi M.,Islamic Azad University at Ardabil
IEEE Antennas and Wireless Propagation Letters | Year: 2013

This letter proposes a novel printed monopole antenna for ultrawideband applications with dual band-notched function. The antenna consists of a square radiating patch with an inverted T-shaped ring slot, surrounded by a C-shaped slot, which provides a wide usable fractional bandwidth of more than 125% (2.71-12.06 GHz). In this structure, by cutting an inverted T-shaped slot, the impedance bandwidth is effectively improved at the upper frequency. In order to generate single band-notched characteristics, we use an inverted T-shaped slot, surrounded by a C-shaped slot, in the radiating patch. By adding an inverted T-shaped parasitic structure inside the inverted T-shaped slot on the radiating patch, a dual band-notched function is achieved, and also by inserting this parasitic structure, additional resonance is excited, and hence much wider impedance bandwidth can be produced, especially at the higher band. The measured results reveal that the presented dual band-notch monopole antenna offers a wide bandwidth with two notched bands, covering all the 5.2/5.8-GHz WLAN, 3.5/5.5-GHz WiMAX, and 4-GHz C-bands. The designed antenna has a small size of 12 × 18 × 0.8 mm3. © 2002-2011 IEEE. Source

Ojaroudi M.,Islamic Azad University at Ardabil | Ojaroudi N.,Islamic Azad University
IEEE Transactions on Antennas and Propagation | Year: 2014

This article proposes a novel, small, printed rectangular slot antenna for ultra-wideband (UWB) applications with dual band-notch function with band-notch performance. To increase the impedance bandwidth of the rectangular slot antenna and achieve UWB coverage, we use an inverted T-shaped conductor backed plane inside the rectangular slot on the other side of the substrate. Additionally, by using a coupled rotated C-shaped strip around the inverted T-shaped conductor backed plane, a frequency notched band performance has been obtained. The designed antenna has a small size of 20×20 mm2 while showing the radiation performance in the frequency band of 3.04 to over 10.87 GHz with a band rejection performance in the frequency band of 5.03 to 5.94 GHz. Simulated and measured results are presented to validate the usefulness of the proposed antenna structure for UWB applications. © 2013 IEEE. Source

Hazrati Niyari A.,Islamic Azad University at Ardabil
Materials and Design | Year: 2013

Damping is a useful parameter for controlling vibration and movement in the design of the structure. The aim of this work is to develop a novel composite with high damping capacity. In this study, flexural damping responses of triple core (aluminium foam and PMI foam and H100 PVC foam) sandwich panels are investigated. A numerical modelling of the flexural damping response was performed using the ABAQUS software. All calculations about the theoretical approach were performed using the MATLAB software. A good match between the finite element modelling and the theoretical approach was obtained. © 2012 Elsevier Ltd. Source

Abazari R.,Islamic Azad University at Ardabil
Computers and Fluids | Year: 2010

In this work, the G'G-expansion method is proposed for constructing more general exact solutions of the three nonlinear evolution equations arising in fluids science with physical interest namely, Vakhnenko-Parkes equation, generalized regularized long wave (RLW) equation and symmetric regularized long wave (SRLW) equation. Our work is motivated by the fact that the (G′/G)-expansion method provides not only more general forms of solutions but also periodic and solitary waves. If we set the parameters in the obtained wider set of solutions as special values, then some previously known solutions can be recovered. The method appears to be easier and faster by means of a symbolic computation system. © 2010 Elsevier Ltd. Source

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