| Section A: Microwave Technology and Related Topics |
| Manuscript Title: Hybrid Modulated Double Segmented Convex Triangular Serrations for Improved Performance of Compact Antenna Test Range Reflectors |
| Manuscript Id: IJMOT-2007-5-249 |
| Abstract: This paper presented a theoretical and numerical assessment Hybrid Modulated Double Segmented (HMDS) Convex-Triangular by changing number of serrations. Serrating the edges of a compact antenna test range (CATR) reflector is a way to realize a smooth ripple-free quiet zone. In this paper an attempt is made to analyze the HMDS convex triangular serration geometry. The investigation was based on diffraction theory and, more specifically, the Fresnel diffraction formulation. This new HMDS concept is that it is relatively simple to apply to existing reflectors. Application of serrated edges has been shown to be a good method to control diffraction at the edges of the reflectors. However, in order to get some insight into the positive effect of serrated edges a technique used known as Physical Optics (PO). Ripple free and enhanced quiet zone width are observed for specific values of width modulation factors per serration. |
| Authors: T. Venkata Rama Krishna, P. Siddaiah,B. Prabhakara Rao |
Category: Microwave Technology Submitted On: 11/16/2007 Full Text [PDF] Pg.Nos: 1-6
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| Manuscript Title: A diamond like low VSWR antenna for UWB system |
| Manuscript Id: IJMOT-2007-7-257 |
| Abstract: A coplanar fed diamond shaped antenna;
with very low voltage standing wave ratio (VSWR)
is presented for ultra wideband (UWB)
applications. Different design parameters are
optimized and the measured return loss below
-14dB (VSWR 1.5:1) is from 3.45~12.4GHz.
Radiation pattern of the proposed design is also
measured and discussed. |
| Authors: Salman Naeem Khan, Jiang Xiong, Sailing He |
Category: Microwave Technology Submitted On: 10/19/2007 Full Text [PDF] Pg.Nos: 7-10
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| Manuscript Title: New Bandwidth Enhancement Technique for Microstrip Patch |
| Manuscript Id: IJMOT-2007-8-264 |
| Abstract: Here we proposed a method to optimize bandwidth with respect to radiation quality factor Qr for a novel and new designed planar antenna. Slicing a substrate into two thin layer substrates, an impedance bandwidth of 12% is achieved while reducing the volume by 44.5%. The technique proposed shows that instead of single thick substrate if two thin substrates are used, an enhancement of impedance bandwidth takes place while maintaining high antenna gain and radiation efficiency. This is a new and novel technique for bandwidth enhancement in microstrip patch antenna and is quite different from stacked antenna. In this paper, we sliced a substrate into two thin substrates each of 1mm thick to achieve a bandwidth of 12%, radiation efficiency of 80.5549% and antenna efficiency of 79.5175% with an overall volume reduction of 44.5%. While a single substrate of thickness 2.5mm which is more than the total thickness of the discussed structure gives only 5% bandwidth for same antenna dimension. |
| Authors: P K Patra, Dr S S Pattnaik and Swapna Devi |
Category: Microwave Technology Submitted On: 8/25/2007 Full Text [PDF] Pg.Nos: 11-15
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| Manuscript Title: On the Behavior of Square Patch Antenna with Koch Fractal Boundary with Different Indentation Angles |
| Manuscript Id: IJMOT-2007-8-265 |
| Abstract: Square patch antenna having Koch fractal boundary with varying Indentation angle is presented. The effect of Indentation angle of the fractal boundary on resonant frequency, size and bandwidth is studied. It is shown that the size is reduced with change in the indentation angle of the fractal boundary without much effect on the gain of the antenna. The impedance bandwidth and the resonance frequency of the proposed fractal boundary patch antenna are related to the indentation angle of the boundary. |
| Authors: P Nageswara Rao, N V S N Sarma |
Category: Microwave Technology Submitted On: 11/8/2007 Full Text [PDF] Pg.Nos: 16-21
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| Manuscript Title: CPW Fed Tapered Slot Antenna for 5 GHz Band Applications |
| Manuscript Id: IJMOT-2007-8-267 |
| Abstract: Main objective of this paper is to give a novel approach in the design and development of Coplanar Waveguide fed tapered slot antenna for various 5 to 6 GHZ frequency band applications. Antenna is fabricated using FR4 substrate with dielectric constant of 4.4. The fundamental parameters of the antenna such as bandwidth, return loss, gain, radiation pattern and polarization are obtained. All meets the acceptable antenna standards. The measured input impedance bandwidth (return loss < -10 dB) of the prototype antenna is 21% (4.8–6 GHz). The radiation patterns are bidirectional in the E-plane and H-plane. The simulated peak antenna gain is 3.1 dBi at 5.48 GHz. Procedure to improve the peak gain is also presented. Simulation tool, based on the method of moments (ZELAND IE3D version 12.0) has been used to analyze and optimize the antenna. |
| Authors: K Balamanikandan, Dr S Raghavan, T Shanmuganantham |
Category: Microwave Technology Submitted On: 12/18/2007 Full Text [PDF] Pg.Nos: 22-26
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| Manuscript Title: Dual Band E-shaped Patch Antenna with Coplanar Parasitic Elements |
| Manuscript Id: IJMOT-2007-9-268 |
| Abstract: A dual band E-shaped patch antenna with coplanar parasitic elements is analyzed using equivalent circuit concept. It is found that the frequency ratio of lower and upper resonance frequencies varies from 1.75 to 1.87 for the entire range of gap. The frequency band for lower resonance increases from 98 MHz (bandwidth 8.59 %) to 133 MHz (bandwidth 13.52 %) for the entire range of gap whereas for upper resonance it decreases from 329 MHz (bandwidth 15.43 %) to 124 MHz (bandwidth 7.20 %). A bandwidth of 11.24% is found same for a given gap length of 0.34 cm for both the resonance frequencies. The radiation patterns for two resonance frequencies are almost similar for a given gap. |
| Authors: J A Ansari and Ram Brij Ram |
Category: Microwave Technology Submitted On: 9/5/2007 Full Text [PDF] Pg.Nos: 27-34
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| Manuscript Title: A NOTE ON THE ANGULAR POWER SPECTRUM OF SCATTERED RADIATION BY ANISOTROPIC LAYER OF COLLISIONAL MAGNETIZED TURBULENT PLASMA |
| Manuscript Id: IJMOT-2007-9-269 |
| Abstract: Statistical characteristics of the angular power spectrum (broadening and displacement of its maximum) of multiply scattered electromagnetic waves by plane layer of turbulent anisotropic magnetized collisional plasma are considered. The influence of distances between the emitter as well as the receiver (they are located in opposite sides with respect to scattered layer) and layer’s boundaries is analyzed for anisotropic Gaussian correlation function describing the irregularities of electron density fluctuations with various parameter of anisotropy and the angle of inclination of prolate irregularities with respect to the external magnetic field. Numerical calculations have been carried out for F region of the ionosphere. |
| Authors: George Jandieri,A. Ishimaru, V.G. Jandieri, A.G. Khantadze, A.I. Gvelesiani, K.V. Kotetishvili, T.N. Bzhalava |
Category: Microwave Technology Submitted On: 9/21/2007 Full Text [PDF] Pg.Nos: 35-44
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| Section B: Optical Technology and Related Topics |
| Manuscript Title: Experimental Method for Verifying the Bistability and Theoretical Model of the Semiconductor Laser Diode Made by the Rate Equations |
| Manuscript Id: IJMOT-2007-6-251 |
| Abstract: The paper report about experiments and theoretical results, which led to the verification of optical bistability behavior on the specially modified laser diode (BLD) created on the structure with saturable absorption section. The bistability, was proved by the time method for bistability impulse verification.
With the use of the bistability verification method, basic parameters of the hystereses loop of the W-A characteristic samples of the realized BLD were determined. The mathematic model of the W-A characteristic was derived by solution of the rate equation system, which was used for the simulation of the W-A characteristic of the realized BLD. For selected operating points of the simulated W-A characteristics the element values of the electrical equivalent circuit of the BLD for small changes of signal were calculated.
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| Authors: Vitezslav Jerabek, Ivan Huttel, Vaclav Prajzler, Zdenek Burian |
Topic: Optical Technology Submitted On: 6/7/2007 Full Text [PDF] Pg.Nos: 45-53
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| Manuscript Title: Blocking Performance analysis of wavelength assignment algorithms in WDM networks |
| Manuscript Id: IJMOT-2007-8-262 |
| Abstract: WDM is the emerging and the dominant technology for the next generation optical networks. Sitting in the heart of WDM is Routing and Wavelength Assignment (RWA) problem. There are two solutions for this RWA problem; one is to divide this problem into two sub problems and the other is to take this problem as a single problem. This paper deals with the division of the problem into two sub problem i.e. routing problem and wavelength assignment problem. A number of routing and wavelength assignment algorithms have been proposed in literature. In this paper, a new algorithm for wavelength assignment has been proposed and the performance of the new wavelength assignment algorithm is evaluated in terms of blocking probability and fairness. |
| Authors: Amit Wason, R. S. Kaler |
Topic: Optical Technology Submitted On: 8/7/2007 Full Text [PDF] Pg.Nos: 54-61
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