| Section A: Microwave Technology and Related Topics |
| Manuscript Title: Compact Tunable and Dual band Circular Microstrip Antenna for GSM and Bluetooth Applications |
| Manuscript Id: IJMOT-2008-11-407 |
| Abstract: A Circular Microstrip Antenna with slot cut in it for tunable and dual band operation has been presented. The existence of an electrically small slot along the feed axis or the perpendicular axis changes the resonant frequency of the patch leading to tunability. If both slots co-exist and are of comparable lengths, which equals to greater than half of the radius, dual frequency operation is obtained. A design has been proposed for obtaining dual band operation for GSM 1800/1900 - Bluetooth 2450 MHz. Experiments have been performed to validate the theoretical results. |
| Authors: K P Ray, S Nikhil, A Nair |
Category: Microwave Technology Submitted On: 3/28/2009 Full Text [PDF] Pg.Nos: 205-210
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| Manuscript Title: Design of Printed Log Periodic EMI Sensor |
| Manuscript Id: IJMOT-2009-1-418 |
| Abstract: This paper describes the design aspects of
a printed log periodic EMI Sensor to operate in a
specific band of frequencies. A parametric study is
conducted using commercial software IE3D, based
on Method of Moments (MoM) algorithm. The
characteristics of the proposed sensor are
determined in terms of return loss, radiation
pattern, gain and Antenna factor. A prototype with
dimensions based on the simulations is built and
tested. A comparison with experimental results
shows good agreement. |
| Authors: Nisha Gupta and Md. Anjarul Haque |
Category: Microwave Technology Submitted On: 1/16/2009 Full Text [PDF] Pg.Nos: 211-215
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| Manuscript Title: A CAD Oriented Model for Calculating the Characteristic Parameters of Broadside - Coupled CPW Based On Artificial Neural Networks |
| Manuscript Id: IJMOT-2009-1-422 |
| Abstract: In recent years, Computer Aided Design (CAD)based on Artificial Neural Networks (ANNs) have been introduced for microwave modeling simulation and optimization. In this paper, the characteristic parameters of Broadside - Coupled Coplanar Waveguides (BSCCPWs) have been determined with the use of ANN model. Eight learning algorithms, Levenberg - Marquart(LM), Bayesian Regularization (BR),Quasi–Newton (QN), Scaled Conjugate Gradient (SCG), Conjugate Gradient of Fletcher – Powell(CGF) , Resilient Propagation (RP), Conjugate Gradient back- propagation with Polak-Ribiere (CGP) and Gradient Descent (GD) are used to train the Multi- Layer Perceptron Neural Networks (MLPNNs). The results of neural models presented in this paper are compared with the results of Conformal Mapping Technique (CMT). When the performances of neural models are compared with each other, the best results are obtained from the neural networks trained by LM and BR algorithms.
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| Authors: P. Thiruvalar Selvan, S. Raghavan |
Category: Microwave Technology Submitted On: 1/28/2009 Full Text [PDF] Pg.Nos: 216-223
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| Manuscript Title: A New non linear optimization for microwave active circuits using a selective invariant transform |
| Manuscript Id: IJMOT-2009-3-431 |
| Abstract: Abstract – The main objective of this paper is to describe one way of analysis of microwave transistors, based on the transformation of the reflection coefficient for an amplifier or a microwave oscillator. This improved method is based on a selective optimization of the circuit. This way consists on introducing a transformation invariant which allows to test the appropriate transistor for a given frequency bandwidth.
The transformation invariant is called coefficient N, and it determine very quickly, the possible modifications of the active multiport network by external circuits connected to it. This procedure is applied by looking at the microwave transistor as a three port or as an equivalent two-port. The present method appears to be accurate and fast in the design of a microwave oscillator based on H.F transistors
Keywords: Microwave oscillator, Optimization, Computer aided design, H.F transistor.
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| Authors: Aidel Salih, Boucenna Noreddine, Belaidi Salim |
Category: Microwave Technology Submitted On: 3/19/2009 Full Text [PDF] Pg.Nos: 224-230
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| Manuscript Title: Near-field narrowband antennas measured in cryogenic environment |
| Manuscript Id: IJMOT-2009-3-433 |
| Abstract: Narrowband bow-tie antennas have been studied in near-field configuration to transmit microwave signals in the 8-12GHz frequency band from the cold stage of cryogenic systems. The coupling between two antennas respectively placed on the cold stage and on a stage at room temperature has been measured for different temperatures of the cold stage ranging from 300K down to 12K. An average transmission of -5.82dB at 300K and -4.76dB at 12K has been measured in the 7.1-8.2GHz frequency band. |
| Authors: David Bouis, Pascal Febvre, Vincent Goudard |
Category: Microwave Technology Submitted On: 3/25/2009 Full Text [PDF] Pg.Nos: 231-234
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| Manuscript Title: Harmonic Suppressed Miniaturized Koch Hybrid Coupler for IEEE802. 11b/g Wireless Applications Using Circular Defected Ground Structure |
| Manuscript Id: IJMOT-2009-3-435 |
| Abstract: Abstract: A new 180o harmonic suppressed miniaturized Koch hybrid coupler is proposed using circular Defected Ground Structures (DGS).In order to validate the proposed design, circular DGS Koch hybrid coupler is fabricated and measured using Microstrip transmission line at operating frequency of 2.44GHz.The circular DGS Koch hybrid coupler measured results are compared with those of a conventional rat-race hybrid coupler. The measured results verify the 177.83o phase difference between two output ports. Also it has effectively suppressed the 3rd order harmonics of operating frequency by adding circular DGS on the backside metallic plate of Koch hybrid coupler. By embedding the circular DGS section, it is observed that the resonant frequency of the Koch hybrid coupler is significantly lowered, which can lead to a large amount of size reduction with harmonic suppression. Measurements of fabricated coupler prototype are in good agreement with simulation results. |
| Authors: K.Annaram , Dr.S.Raju,Dr.V.Abhaikumar |
Category: Microwave Technology Submitted On: 3/30/2009 Full Text [PDF] Pg.Nos: 235-241
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| Manuscript Title: Algorithm for Model Dimensions Estimation of Memory Polynomial-Based RF Transmitters / Power Amplifiers Behavioral Models |
| Manuscript Id: IJMOT-2009-4-436 |
| Abstract: In this paper, a novel accurate model dimensions estimation algorithm suitable for memory polynomial based behavioral models is proposed. For a predefined model performance criterion, the proposed algorithm selects the nonlinearity order and the memory depth for a trade-off between performance and computational complexity. Indeed, the nonlinearity order is first chosen to minimize the conditioning number of the Vandermonde matrix. Then, the memory depth is optimized to decrease the overall the number of coefficients in the model. The proposed algorithm is experimentally validated on a high power 3G Doherty amplifier prototype driven by various WCDMA multi-carrier signals. This validation showed that the model performance was maintained while its complexity was reduced by 40% and its robustness improved by 20%. |
| Authors: Mayada Younes, Oualid Hammi, Fadhel M. Ghannouchi |
Category: Microwave Technology Submitted On: 4/1/2009 Full Text [PDF] Pg.Nos: 242-247
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| Manuscript Title: Design of Rotman Type Lens for Multiple Beam Forming |
| Manuscript Id: IJMOT-2008-12-412 |
| Abstract: Design of Rotman type beam forming bootlace lens have been discussed. Scattering matrix of the bootlace lens has been evaluated using the contour integral approach. Radiation characteristics of the bootlace lens have been investigated with different types of the micorstrip antenna. |
| Authors: Ravi Pratap Singh Kushwah, P.K. Singhal, P.C. Sharma |
Category: Microwave Technology Submitted On: 12/11/2008 Full Text [PDF] Pg.Nos: 248-256
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| Section B: Optical Technology and Related Topics |
| Manuscript Title: Stability Criteria in Soliton Transmission with Filters and Nonlinear Gain Devices |
| Manuscript Id: IJMOT-2009-3-432 |
| Abstract: Polarization mode dispersion in single mode fibers occurs due to random birefringence which results in propagation of soliton pulse with the emission of dispersive waves. Due to these dispersive waves soliton pulse loses its energy and gets broadened during the transmission along the fiber. This paper examines a solution to this problem, which uses controlling techniques such as filters and nonlinear gain devices to reduce the effects of polarization mode dispersion. It presents the numerical simulations of coupled nonlinear Schrödinger equations using split-step Fourier method to quantify the energy decay, pulse broadening and depolarization of soliton pulses with and without controlling techniques. From simulation results, we show that the periodical insertion of nonlinear gain devices significantly improves the stability of the soliton. |
| Authors: DOWLURU RAVI KUMAR, B.PRABHAKARA RAO |
Topic: Optical Technology Submitted On: 3/20/2009 Full Text [PDF] Pg.Nos: 257-262
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