2017 7th IEEE International Symposium on Microwave, Antenna, Propagation, and EMC Technologies (MAPE), 2017
Sparse antenna array has many advantages like low mutual coupling, directive beam and cost effect... more Sparse antenna array has many advantages like low mutual coupling, directive beam and cost effective because of less number of elements as compare to equally spaced antenna array. While the main limitation in this array is of high side lobe levels because of different inter element spacing. In this paper optimized values of elements spacing and excitation amplitude for sparse linear antenna array are achieved to minimize the peak side lobe level using particle swarm optimization (PSO) with better convergence rate. Random values of spacing are considered in half and one wave length range. And maintained the main beam direction.
Journal of Electromagnetic Waves and Applications, 2016
The high-frequency field expressions for the refracted waves from the dielectric 3D elliptical le... more The high-frequency field expressions for the refracted waves from the dielectric 3D elliptical lens embedded in homogeneous and reciprocal chiral medium around the focal region are derived using an asymptotic method based on Maslov’s theory. Ray-based Geometric Optics (GO) technique was initially used to derive the expressions for the electrical field intensities for both left circular polarized and right circular polarized waves which are inherited in the chiral medium. However, GO method is not applicable at the focal points due to the shrinking of ray volume at these points which causes unreal singularities. Therefore, an asymptotic method based on Maslov’s theory is applied to derive the fields at the focal points. Moreover, the effect of chirality parameter on the behavior of focal points electric field intensities are indicated using the line plots obtained from the numerical solution of the derived equations using MATLAB software. A special case of the dielectric 3D elliptical lens placed in achiral medium is also discussed using the expressions.
An open ended slot with narrow rectangular shape filled with dielectric material act as an Omni-d... more An open ended slot with narrow rectangular shape filled with dielectric material act as an Omni-directional antenna is proposed. To achieve good impedance matching within the desired band of interest, the slot is excited by 50Ω coaxial cable. The proposed antenna has design at S-band. Nowadays, most communication systems require antennas with features like compact size, aerodynamically suitable and light weight. A simple coupled slot blade antenna is design for airborne applications. The simulated and measured reflection characteristics of the antenna along with the radiation patterns and gain are presented and discussed. Moreover, the ability of the antenna to withstand sturdy conditions and to avoid the light striking by blocking the DC current is also discussed and finally the conclusion is drawn accordingly.
The recent trends in airborne communication system has result in requirement for design and devel... more The recent trends in airborne communication system has result in requirement for design and development of broadband antenna with features like compact size, aerodynamically suitable and light weight. A slanted monopole radiator is used which is enclosed in a radome. The proposed antenna has design at S-band and can be scaled to any other band. The simulated and measured reflection characteristics of the antenna along with the radiation patterns and gain are presented and discussed. Moreover, the ability of the antenna to withstand sturdy conditions and to avoid the light striking by blocking the DC current is also discussed and finally the conclusion is drawn accordingly.
Optik - International Journal for Light and Electron Optics, 2016
In this paper, a 3D elliptical reflector coated with chiral medium has been analyzed to find the ... more In this paper, a 3D elliptical reflector coated with chiral medium has been analyzed to find the field in the vicinity of focal region using geometrical optics (GO) and Maslov's method. As the GO approximation does not work at the focal points due to unreal singularities occur at these points. Therefore, Maslov's theory has been applied to derive the expressions which are also valid at focal points. These focal points usually are of great importance in all practical applications. The effects of thickness (d) of the coated medium, chirality parameter (β) of the coated medium and permittivity (ɛ) of the medium on the focal region fields are illustrated. A special case of elliptical reflector coated with conventional medium has also been evaluated. The derived fields expressions are plotted using MATLAB software.
TELKOMNIKA Indonesian Journal of Electrical Engineering, 2015
A low profile multi layer miniaturized unit cell frequency selective surface (FSS) with second-or... more A low profile multi layer miniaturized unit cell frequency selective surface (FSS) with second-order band-pass response is design. The metallic layers in the form of capacitive patches and inductive grids are separated by dielectric substrates. The non-resonant sub-wavelength unit cells with unit cell dimensions and periodicities on the order of 0.15λ. The overall thickness of approximately 0.03λ is designed which is useful at lower frequencies with long wavelengths. The FSS exhibit a stable frequency response to different angles of incidence and polarizations. The analysis and synthesis of the FSS is done using equivalent circuit method and simulated using CST microwave studio at X-band.
Focused high frequency electromagnetic waves reflected from a PEC spherical surface placed in hom... more Focused high frequency electromagnetic waves reflected from a PEC spherical surface placed in homogeneous, reciprocal and isotropic medium with high chirality parameter are analyzed. The value of the chirality parameter is set such that it simultaneously supports modes of negative and positive phase velocities. Present work is an extension of the previous work, in which the chiral medium supports only positive phase velocity. Using the previous derived expressions, line plots in the focal region are obtained.
TELKOMNIKA Indonesian Journal of Electrical Engineering
A multi band sleeve dipole antenna for jammer application is proposed. The antenna can cover band... more A multi band sleeve dipole antenna for jammer application is proposed. The antenna can cover band in which mobile and other wireless devices operate. The design antenna shows very good omni-directional characteristics and scattering parameter S11 value less than -10db. The dipole is made of two concentric hallow cylinder with different radius and different lengths. The antenna is fed at the center with coaxial cable pass through the bottom cylinder and thus avoids the use of complicated balun network. The impedance bandwidth and the radiation pattern are measured and analyzed both at 900 MHz and 1.8 GHz. The antenna can also be used GSM/DCS/WCDMA/CDMA2000/ TD-SCDMA /WLAN applications at both indoor and outdoor platform.
2017 7th IEEE International Symposium on Microwave, Antenna, Propagation, and EMC Technologies (MAPE), 2017
Sparse antenna array has many advantages like low mutual coupling, directive beam and cost effect... more Sparse antenna array has many advantages like low mutual coupling, directive beam and cost effective because of less number of elements as compare to equally spaced antenna array. While the main limitation in this array is of high side lobe levels because of different inter element spacing. In this paper optimized values of elements spacing and excitation amplitude for sparse linear antenna array are achieved to minimize the peak side lobe level using particle swarm optimization (PSO) with better convergence rate. Random values of spacing are considered in half and one wave length range. And maintained the main beam direction.
Journal of Electromagnetic Waves and Applications, 2016
The high-frequency field expressions for the refracted waves from the dielectric 3D elliptical le... more The high-frequency field expressions for the refracted waves from the dielectric 3D elliptical lens embedded in homogeneous and reciprocal chiral medium around the focal region are derived using an asymptotic method based on Maslov’s theory. Ray-based Geometric Optics (GO) technique was initially used to derive the expressions for the electrical field intensities for both left circular polarized and right circular polarized waves which are inherited in the chiral medium. However, GO method is not applicable at the focal points due to the shrinking of ray volume at these points which causes unreal singularities. Therefore, an asymptotic method based on Maslov’s theory is applied to derive the fields at the focal points. Moreover, the effect of chirality parameter on the behavior of focal points electric field intensities are indicated using the line plots obtained from the numerical solution of the derived equations using MATLAB software. A special case of the dielectric 3D elliptical lens placed in achiral medium is also discussed using the expressions.
An open ended slot with narrow rectangular shape filled with dielectric material act as an Omni-d... more An open ended slot with narrow rectangular shape filled with dielectric material act as an Omni-directional antenna is proposed. To achieve good impedance matching within the desired band of interest, the slot is excited by 50Ω coaxial cable. The proposed antenna has design at S-band. Nowadays, most communication systems require antennas with features like compact size, aerodynamically suitable and light weight. A simple coupled slot blade antenna is design for airborne applications. The simulated and measured reflection characteristics of the antenna along with the radiation patterns and gain are presented and discussed. Moreover, the ability of the antenna to withstand sturdy conditions and to avoid the light striking by blocking the DC current is also discussed and finally the conclusion is drawn accordingly.
The recent trends in airborne communication system has result in requirement for design and devel... more The recent trends in airborne communication system has result in requirement for design and development of broadband antenna with features like compact size, aerodynamically suitable and light weight. A slanted monopole radiator is used which is enclosed in a radome. The proposed antenna has design at S-band and can be scaled to any other band. The simulated and measured reflection characteristics of the antenna along with the radiation patterns and gain are presented and discussed. Moreover, the ability of the antenna to withstand sturdy conditions and to avoid the light striking by blocking the DC current is also discussed and finally the conclusion is drawn accordingly.
Optik - International Journal for Light and Electron Optics, 2016
In this paper, a 3D elliptical reflector coated with chiral medium has been analyzed to find the ... more In this paper, a 3D elliptical reflector coated with chiral medium has been analyzed to find the field in the vicinity of focal region using geometrical optics (GO) and Maslov's method. As the GO approximation does not work at the focal points due to unreal singularities occur at these points. Therefore, Maslov's theory has been applied to derive the expressions which are also valid at focal points. These focal points usually are of great importance in all practical applications. The effects of thickness (d) of the coated medium, chirality parameter (β) of the coated medium and permittivity (ɛ) of the medium on the focal region fields are illustrated. A special case of elliptical reflector coated with conventional medium has also been evaluated. The derived fields expressions are plotted using MATLAB software.
TELKOMNIKA Indonesian Journal of Electrical Engineering, 2015
A low profile multi layer miniaturized unit cell frequency selective surface (FSS) with second-or... more A low profile multi layer miniaturized unit cell frequency selective surface (FSS) with second-order band-pass response is design. The metallic layers in the form of capacitive patches and inductive grids are separated by dielectric substrates. The non-resonant sub-wavelength unit cells with unit cell dimensions and periodicities on the order of 0.15λ. The overall thickness of approximately 0.03λ is designed which is useful at lower frequencies with long wavelengths. The FSS exhibit a stable frequency response to different angles of incidence and polarizations. The analysis and synthesis of the FSS is done using equivalent circuit method and simulated using CST microwave studio at X-band.
Focused high frequency electromagnetic waves reflected from a PEC spherical surface placed in hom... more Focused high frequency electromagnetic waves reflected from a PEC spherical surface placed in homogeneous, reciprocal and isotropic medium with high chirality parameter are analyzed. The value of the chirality parameter is set such that it simultaneously supports modes of negative and positive phase velocities. Present work is an extension of the previous work, in which the chiral medium supports only positive phase velocity. Using the previous derived expressions, line plots in the focal region are obtained.
TELKOMNIKA Indonesian Journal of Electrical Engineering
A multi band sleeve dipole antenna for jammer application is proposed. The antenna can cover band... more A multi band sleeve dipole antenna for jammer application is proposed. The antenna can cover band in which mobile and other wireless devices operate. The design antenna shows very good omni-directional characteristics and scattering parameter S11 value less than -10db. The dipole is made of two concentric hallow cylinder with different radius and different lengths. The antenna is fed at the center with coaxial cable pass through the bottom cylinder and thus avoids the use of complicated balun network. The impedance bandwidth and the radiation pattern are measured and analyzed both at 900 MHz and 1.8 GHz. The antenna can also be used GSM/DCS/WCDMA/CDMA2000/ TD-SCDMA /WLAN applications at both indoor and outdoor platform.
Uploads