2009 World Congress on Nature & Biologically Inspired Computing (NaBIC), 2009
... 8 9 10 11 12 13 14 15 16 17 18 Frequency (GHz) S11 (d B) 1112 2009 World Congress on Nature &... more ... 8 9 10 11 12 13 14 15 16 17 18 Frequency (GHz) S11 (d B) 1112 2009 World Congress on Nature & Biologically Inspired Computing (NaBIC 2009) Page 3. ... S11 (d B) 2009 World Congress on Nature & Biologically Inspired Computing (NaBIC 2009) 1113 Page 4. ...
In this paper, the general problem of electromagnetic coupling between two dissimilar regions, bo... more In this paper, the general problem of electromagnetic coupling between two dissimilar regions, both open at infinity, via an aperture of arbitrary shape is considered. The aperture is assumed to be located in a conducting screen of infinitesimal thickness. The analysis is based on the “generalised network formulation” for aperture problems. Field equivalence principle is first used to divide the problem into two parts. Next, boundary conditions are invoked to obtain a magnetic field integral equation (MFIE) which is then solved using the method of moments (MOM). Triangular patches, with appropriately defined basis functions, are used to model the arbitrarily shaped aperture. This leads to a matrix equation whose solution requires the evaluation of integrals with bounded and unbounded kernels over a triangular domain. Representative results are given for rectangular, circular, elliptic, diamond-shaped, cross-shaped and H-shaped apertures.
A moment-method analysis of waveguide-backed apertures of arbitrary shape is presented. The “gene... more A moment-method analysis of waveguide-backed apertures of arbitrary shape is presented. The “generalized network formulation” for aperture problems[1] has been used for formulating the problem in terms of an operator equation. Triangular patch modeling, with suitably defined basis functions, is utilized for the solution of the operator equation. Representative aperture shapes considered include rectangular, circular, elliptic, diamond, and H. Numerical results are presented for equivalent surface magnetic current, equivalent aperture admittance and antenna power gain patterns.
Introduction.- Method of Moment Formulation of Coupling through Apertures.- Fractal Frequency Sel... more Introduction.- Method of Moment Formulation of Coupling through Apertures.- Fractal Frequency Selective Diaphragms in Rectangular Waveguide.- Electromagnetic Transmission through Fractal Apertures in Conducting Screen.- Radiation from Rectangular Waveguide-Fed Fractal Aperture Antennas.- Investigations on Cavity-Backed Fractal Aperture Antennas.- Conclusions and Future Work.
In this paper, measurement and simulation results for modeling of wave propagation in an indoor e... more In this paper, measurement and simulation results for modeling of wave propagation in an indoor environment are presented. Complex wideband frequency responses centered at frequency 3.6 GHz have been measured and approximation to the impulse response of the channel is obtained from the Inverse Fourier Transform of the frequency response. Narrowband measurements were conducted at 3.3, 3.6 and 3.9 GHz to compute the Path Loss Law. All the experiments were performed in a triple-storied office building. A ray tracing technique has been used to simulate the wave propagation in the building. Ray tubes have been used to model the wave propagation and all the reflected and transmitted ray tubes from interfaces have been included. A program has been developed in MATLAB that can be used to simulate wave propagation in large 3D buildings. Simulation results have been verified by comparing them with measured data.
Antennas and Propagation Society International Symposium, 2008
Particle swarm optimization (PSO) procedure has been applied to find out a compensation for degra... more Particle swarm optimization (PSO) procedure has been applied to find out a compensation for degraded pattern of a failed antenna array by amplitude only perturbation of few of the unfailed elements. The optimization technique finds the optimum amplitude levels of some of the unfailed elements in the array, so that the compensated pattern will match with the pattern of the
International Journal of RF and Microwave Computer-Aided Engineering, 2010
Page 1. Investigations on Fractal Frequency Selective Diaphragms in Rectangular Waveguide Basudeb... more Page 1. Investigations on Fractal Frequency Selective Diaphragms in Rectangular Waveguide Basudeb Ghosh, Sachendra N. Sinha, MV Kartikeyan Department of Electronics and Computer Engineering, Indian Institute of Technology Roorkee, Roorkee 247667, India ...
This paper presents the experimental evaluation of the ′Specific Absorption Rate′ (SAR) reduction... more This paper presents the experimental evaluation of the ′Specific Absorption Rate′ (SAR) reduction in a human head due to radio frequency (RF) shields attached to a mobile handset. Shields of various shapes and sizes were made from a nickel-zinc spinel ferrite. The human head ...
IEEE Transactions on Antennas and Propagation, 2010
AbstractWe investigate the properties of fractal apertures fed by a rect-angular waveguide. The ... more AbstractWe investigate the properties of fractal apertures fed by a rect-angular waveguide. The self-similarity and space-filling properties of frac-tals have been exploited to achieve multi-band radiation. Some self-affine fractal geometries, suitable for ...
2009 World Congress on Nature & Biologically Inspired Computing (NaBIC), 2009
... 8 9 10 11 12 13 14 15 16 17 18 Frequency (GHz) S11 (d B) 1112 2009 World Congress on Nature &... more ... 8 9 10 11 12 13 14 15 16 17 18 Frequency (GHz) S11 (d B) 1112 2009 World Congress on Nature & Biologically Inspired Computing (NaBIC 2009) Page 3. ... S11 (d B) 2009 World Congress on Nature & Biologically Inspired Computing (NaBIC 2009) 1113 Page 4. ...
In this paper, the general problem of electromagnetic coupling between two dissimilar regions, bo... more In this paper, the general problem of electromagnetic coupling between two dissimilar regions, both open at infinity, via an aperture of arbitrary shape is considered. The aperture is assumed to be located in a conducting screen of infinitesimal thickness. The analysis is based on the “generalised network formulation” for aperture problems. Field equivalence principle is first used to divide the problem into two parts. Next, boundary conditions are invoked to obtain a magnetic field integral equation (MFIE) which is then solved using the method of moments (MOM). Triangular patches, with appropriately defined basis functions, are used to model the arbitrarily shaped aperture. This leads to a matrix equation whose solution requires the evaluation of integrals with bounded and unbounded kernels over a triangular domain. Representative results are given for rectangular, circular, elliptic, diamond-shaped, cross-shaped and H-shaped apertures.
A moment-method analysis of waveguide-backed apertures of arbitrary shape is presented. The “gene... more A moment-method analysis of waveguide-backed apertures of arbitrary shape is presented. The “generalized network formulation” for aperture problems[1] has been used for formulating the problem in terms of an operator equation. Triangular patch modeling, with suitably defined basis functions, is utilized for the solution of the operator equation. Representative aperture shapes considered include rectangular, circular, elliptic, diamond, and H. Numerical results are presented for equivalent surface magnetic current, equivalent aperture admittance and antenna power gain patterns.
Introduction.- Method of Moment Formulation of Coupling through Apertures.- Fractal Frequency Sel... more Introduction.- Method of Moment Formulation of Coupling through Apertures.- Fractal Frequency Selective Diaphragms in Rectangular Waveguide.- Electromagnetic Transmission through Fractal Apertures in Conducting Screen.- Radiation from Rectangular Waveguide-Fed Fractal Aperture Antennas.- Investigations on Cavity-Backed Fractal Aperture Antennas.- Conclusions and Future Work.
In this paper, measurement and simulation results for modeling of wave propagation in an indoor e... more In this paper, measurement and simulation results for modeling of wave propagation in an indoor environment are presented. Complex wideband frequency responses centered at frequency 3.6 GHz have been measured and approximation to the impulse response of the channel is obtained from the Inverse Fourier Transform of the frequency response. Narrowband measurements were conducted at 3.3, 3.6 and 3.9 GHz to compute the Path Loss Law. All the experiments were performed in a triple-storied office building. A ray tracing technique has been used to simulate the wave propagation in the building. Ray tubes have been used to model the wave propagation and all the reflected and transmitted ray tubes from interfaces have been included. A program has been developed in MATLAB that can be used to simulate wave propagation in large 3D buildings. Simulation results have been verified by comparing them with measured data.
Antennas and Propagation Society International Symposium, 2008
Particle swarm optimization (PSO) procedure has been applied to find out a compensation for degra... more Particle swarm optimization (PSO) procedure has been applied to find out a compensation for degraded pattern of a failed antenna array by amplitude only perturbation of few of the unfailed elements. The optimization technique finds the optimum amplitude levels of some of the unfailed elements in the array, so that the compensated pattern will match with the pattern of the
International Journal of RF and Microwave Computer-Aided Engineering, 2010
Page 1. Investigations on Fractal Frequency Selective Diaphragms in Rectangular Waveguide Basudeb... more Page 1. Investigations on Fractal Frequency Selective Diaphragms in Rectangular Waveguide Basudeb Ghosh, Sachendra N. Sinha, MV Kartikeyan Department of Electronics and Computer Engineering, Indian Institute of Technology Roorkee, Roorkee 247667, India ...
This paper presents the experimental evaluation of the ′Specific Absorption Rate′ (SAR) reduction... more This paper presents the experimental evaluation of the ′Specific Absorption Rate′ (SAR) reduction in a human head due to radio frequency (RF) shields attached to a mobile handset. Shields of various shapes and sizes were made from a nickel-zinc spinel ferrite. The human head ...
IEEE Transactions on Antennas and Propagation, 2010
AbstractWe investigate the properties of fractal apertures fed by a rect-angular waveguide. The ... more AbstractWe investigate the properties of fractal apertures fed by a rect-angular waveguide. The self-similarity and space-filling properties of frac-tals have been exploited to achieve multi-band radiation. Some self-affine fractal geometries, suitable for ...
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