The document compares the radiation patterns of thinned and thickened linear antenna arrays. It finds that thickening reduces the null to null beamwidth without deteriorating sidelobe levels, while thinning raises sidelobe levels and beamwidth and can introduce grating lobes if not done properly. Tables show sidelobe levels and beamwidths decrease as array size increases for both thinned and thickened arrays, but thickened arrays have better performance. Patterns are evaluated for different array sizes and element amplitudes and spacings are listed for selected thinned and thickened arrays.
Enhancing the Radiation Pattern of Phase Array Antenna Using Particle Swarm O...IOSR Journals
The document describes a study that uses particle swarm optimization to enhance the radiation pattern of a phase array antenna by minimizing sidelobe levels. It first provides background on issues with high sidelobes in phase array antennas, such as power losses and interference. It then summarizes previous research using techniques like genetic algorithms for antenna array optimization. The study models the radiation pattern of linear arrays with different element numbers and calculates gain, finding that gain increases with more elements. However, sidelobe levels also increase relatively. Therefore, the study proposes using particle swarm optimization to optimize current excitation and control sidelobe levels while maintaining a narrow beamwidth.
Implementation of Digital Beamforming Technique for Linear Antenna Arraysijsrd.com
A digital Beamforming technique used for increased channel capacity and also increased signal to noise and interference ratio. In smart antenna, different type of radiation pattern of an antenna can be changed either by selecting appropriate weights or by changing the array geometry. This paper presented based on auxiliary phase algorithm by using this algorithm in linear antenna array determine the array pattern approximating the auxiliary function in both amplitude and phase. Cost function involving auxiliary function and array pattern is minimized by modifying the pattern.
Variable radiation pattern from co axial probe fed rectangular patch antenna ...eSAT Journals
Abstract The idea of obtaining variable radiation patterns from the same antenna is important aspect in achieving the adaptive antenna systems. In the EM signal processing the change of radiation signifies the information to be transmitted, its rate of transmission, the geographical changes and direction to transmit etc. i.e. each time when the requirement arises to change the radiation pattern it has to be done to satisfy the conditions. Electronically steerable antennas were used where the antenna radiation will be altered by varying the feed and similar case is applied for shaped patterns from array antenna where the feed to be given will be calculated and given accordingly. In the present concept the metamaterials are used to obtain different radiation patterns occurred at different operating frequencies using the same antenna without changing the antenna physically are varying its feed. Key Words: Inductance, capacitance, operating frequency, variable radiation, enhancement, radiation cancellation.
The document describes the design and testing of a circular microstrip patch array antenna for C-band altimeter systems. It discusses using an array of four circular microstrip elements with equal size and spacing to achieve a gain of 12 dB. The antenna was simulated using HFSS and Microwave Office software. Comparison of simulated and measured results showed good agreement, achieving the design goals.
Designing a pencil beam pattern with low sidelobesPiyush Kashyap
In this paper, a system has been designed for an operational frequency of 1.27 GHz consisting of an 8 element array of parasitic dipoles illuminated by a 4 element center fed array of active dipoles with Dolph-Chebyshev excitation coefficients. The array is designed to achieve a fairly pencil beam pattern suitable for direction of arrival estimation purposes. Array geometry and configuration is optimized for both active and parasitic elements using the PSO tool in FEKO. A directive radiation pattern is obtained with a gain of 14.5 dBi in the broadside direction along with a beamwidth of 30.29o. VSWR of 1.58 is achieved. Further, an iterative least square valued error estimation approach using phase control to achieve a desired array factor pattern for an n-element linear array, has been shown to be effective for larger number of iterations. The array excitation coefficients achieved were consistent with the Dolph-Chebyshev coefficients used in our antenna array design. With the ability to introduce nulls and steering the main beam in desired directions along with a pencil beam radiation pattern, beamsteering has been illustrated and the MUSIC algorithm for direction of arrival estimation has been implemented
A simple, easy and flexible Defected Ground Structure (DGS) is proposed for rectangular arrays and
demonstrated theoretically in here with the aim of achieving suppression of cross polarization resulting improved
polarization purity in radiated fields. The employed DGS appears to be highly efficient in terms of suppressing
Cross Polarization especially in H-plane. A [2×2] array has been designed having aspect ratio of 1.3 and showing
14 dB enhancement in the segregation between the co-polarization to cross-polarization dissemination with
improved impedance Bandwidth.
Analysis of Metamaterial Based Microstrip Array Antennaijceronline
Metamaterials have been intensively researched due to their peculiar features such as negative permittivity and/or permeability and ultra-refraction phenomenon. To satisfy the demand of commonly used wireless communication systems, an antenna which can operate at higher frequencies and enhanced characteristics are desirable. The arrangement of all elements is done that they provide an improvement in bandwidth, directivity return loss etc. The frequency response of a metamaterial can be tailored by varying its characteristics. A new metamaterial structure using square and ring split ring resonator is proposed. Using this metamaterial structure, a microstrip patch antenna is designed with enhanced characteristics such as reduction in return lossfrom-20dB to -36dB with tunability is achieved.
3 d single gaas co axial nanowire solar cell for nanopillar-array photovoltai...ijcsa
Nanopillar array photovoltaics give unique advantages over today’s planar thin films in the areas of
optical properties and carrier collection, arising from their 3D geometry. The choice of the material
system, however, is essential in order to gain the advantage of the large surface/interface area associated
with nanopillars. Therefore, a well known Si and GaAs material are used in the design and studied in this
nanowire application. This work calculates and analyses the performance of the coaxial GaAs nanowire
and compared with that of Si nanowire using a semi-classical method. The current-voltage characteristics
are investigated for both under dark and AM1.5G illumination. It is found that GaAs nanowire gives almost
double efficiency with its counterpart Si nanowire. Their TCAD simulations can be validated reasonably
with that of published experimental result.
Enhancing the Radiation Pattern of Phase Array Antenna Using Particle Swarm O...IOSR Journals
The document describes a study that uses particle swarm optimization to enhance the radiation pattern of a phase array antenna by minimizing sidelobe levels. It first provides background on issues with high sidelobes in phase array antennas, such as power losses and interference. It then summarizes previous research using techniques like genetic algorithms for antenna array optimization. The study models the radiation pattern of linear arrays with different element numbers and calculates gain, finding that gain increases with more elements. However, sidelobe levels also increase relatively. Therefore, the study proposes using particle swarm optimization to optimize current excitation and control sidelobe levels while maintaining a narrow beamwidth.
Implementation of Digital Beamforming Technique for Linear Antenna Arraysijsrd.com
A digital Beamforming technique used for increased channel capacity and also increased signal to noise and interference ratio. In smart antenna, different type of radiation pattern of an antenna can be changed either by selecting appropriate weights or by changing the array geometry. This paper presented based on auxiliary phase algorithm by using this algorithm in linear antenna array determine the array pattern approximating the auxiliary function in both amplitude and phase. Cost function involving auxiliary function and array pattern is minimized by modifying the pattern.
Variable radiation pattern from co axial probe fed rectangular patch antenna ...eSAT Journals
Abstract The idea of obtaining variable radiation patterns from the same antenna is important aspect in achieving the adaptive antenna systems. In the EM signal processing the change of radiation signifies the information to be transmitted, its rate of transmission, the geographical changes and direction to transmit etc. i.e. each time when the requirement arises to change the radiation pattern it has to be done to satisfy the conditions. Electronically steerable antennas were used where the antenna radiation will be altered by varying the feed and similar case is applied for shaped patterns from array antenna where the feed to be given will be calculated and given accordingly. In the present concept the metamaterials are used to obtain different radiation patterns occurred at different operating frequencies using the same antenna without changing the antenna physically are varying its feed. Key Words: Inductance, capacitance, operating frequency, variable radiation, enhancement, radiation cancellation.
The document describes the design and testing of a circular microstrip patch array antenna for C-band altimeter systems. It discusses using an array of four circular microstrip elements with equal size and spacing to achieve a gain of 12 dB. The antenna was simulated using HFSS and Microwave Office software. Comparison of simulated and measured results showed good agreement, achieving the design goals.
Designing a pencil beam pattern with low sidelobesPiyush Kashyap
In this paper, a system has been designed for an operational frequency of 1.27 GHz consisting of an 8 element array of parasitic dipoles illuminated by a 4 element center fed array of active dipoles with Dolph-Chebyshev excitation coefficients. The array is designed to achieve a fairly pencil beam pattern suitable for direction of arrival estimation purposes. Array geometry and configuration is optimized for both active and parasitic elements using the PSO tool in FEKO. A directive radiation pattern is obtained with a gain of 14.5 dBi in the broadside direction along with a beamwidth of 30.29o. VSWR of 1.58 is achieved. Further, an iterative least square valued error estimation approach using phase control to achieve a desired array factor pattern for an n-element linear array, has been shown to be effective for larger number of iterations. The array excitation coefficients achieved were consistent with the Dolph-Chebyshev coefficients used in our antenna array design. With the ability to introduce nulls and steering the main beam in desired directions along with a pencil beam radiation pattern, beamsteering has been illustrated and the MUSIC algorithm for direction of arrival estimation has been implemented
A simple, easy and flexible Defected Ground Structure (DGS) is proposed for rectangular arrays and
demonstrated theoretically in here with the aim of achieving suppression of cross polarization resulting improved
polarization purity in radiated fields. The employed DGS appears to be highly efficient in terms of suppressing
Cross Polarization especially in H-plane. A [2×2] array has been designed having aspect ratio of 1.3 and showing
14 dB enhancement in the segregation between the co-polarization to cross-polarization dissemination with
improved impedance Bandwidth.
Analysis of Metamaterial Based Microstrip Array Antennaijceronline
Metamaterials have been intensively researched due to their peculiar features such as negative permittivity and/or permeability and ultra-refraction phenomenon. To satisfy the demand of commonly used wireless communication systems, an antenna which can operate at higher frequencies and enhanced characteristics are desirable. The arrangement of all elements is done that they provide an improvement in bandwidth, directivity return loss etc. The frequency response of a metamaterial can be tailored by varying its characteristics. A new metamaterial structure using square and ring split ring resonator is proposed. Using this metamaterial structure, a microstrip patch antenna is designed with enhanced characteristics such as reduction in return lossfrom-20dB to -36dB with tunability is achieved.
3 d single gaas co axial nanowire solar cell for nanopillar-array photovoltai...ijcsa
Nanopillar array photovoltaics give unique advantages over today’s planar thin films in the areas of
optical properties and carrier collection, arising from their 3D geometry. The choice of the material
system, however, is essential in order to gain the advantage of the large surface/interface area associated
with nanopillars. Therefore, a well known Si and GaAs material are used in the design and studied in this
nanowire application. This work calculates and analyses the performance of the coaxial GaAs nanowire
and compared with that of Si nanowire using a semi-classical method. The current-voltage characteristics
are investigated for both under dark and AM1.5G illumination. It is found that GaAs nanowire gives almost
double efficiency with its counterpart Si nanowire. Their TCAD simulations can be validated reasonably
with that of published experimental result.
This document analyzes the polarization and transmission effects of antireflection coatings for silicon-on-insulator (SOI) material systems using simulation software. Without a coating, transmission of transverse magnetic (TM) polarized light is slightly higher than transverse electric (TE) polarized light. A single-layer antireflection coating is designed and optimized to increase average transmission by 19%, reducing the polarization effect. However, multilayer coatings did not further increase transmission over the optimized single layer. In conclusion, antireflection coatings can effectively reduce polarization dependence for SOI materials while improving overall light transmission.
Reduction of Mutual Coupling between Closely Spaced Microstrip Antennas Array...TELKOMNIKA JOURNAL
Reducing mutual coupling is a key research area in design of compact microstrip antennas
arrays. To minimize the overall size of the antennas arrays, the distance between them must be very
small, as a result a strong mutual coupling is appears. Periodic structures can help to design a low profile
of antennas arrays and enable to improve their performances by the suppression of surface waves
propagation in a given frequency range. This paper proposes a novel configuration of mushroom-like
electromagnetic band-gap (2D-EBG) structure created by microstrip technology placed between two
antennas arrays to reduce the mutual coupling more than -33.24dB. When 13×2 EBG structures are used,
the mutual coupling reduces to -59.36dB at the operation frequency 5.8GHz of the antennas arrays. A
26.12dB mutual coupling reduction is achieved, which proves that the surface wave is suppressed. The
proposed configuration is designed, optimized, and miniaturized by using electromagnetic software CST
Microwave Studio. The measured results show that there is a good agreement with the computed results.
Three complementary split spiral resonators (CSSRs) are used to reduce mutual coupling between two nearby microstrip patch antennas operating at 6.58 GHz. Simulation and measurement results show that using three vertically arranged CSSRs etched on the ground plane reduces the mutual coupling between the antennas by 23 dB. Characterization of the CSSR unit cell shows it behaves as a single negative metamaterial. The CSSRs block surface waves on the substrate to minimize coupling between the antenna elements while maintaining a low-profile compact structure with minimal impact on antenna performance.
This document summarizes a research paper that presents a dual open stub loaded square microstrip antenna (DOSMSA) for quad-band wireless communication applications. The DOSMSA consists of a square patch with two open stubs placed diagonally. Measurements show the DOSMSA operates over four bands from 2.88-8.55 GHz with gains up to 3.21 dB, compared to 0.8 dB for a basic square microstrip antenna. The DOSMSA design achieves quad-band operation using a simple stub loading technique while reducing the antenna's copper area by 7.8% compared to the basic design. The antenna has broadside radiation patterns and could enable applications in WLAN and WiMAX
Self affine rectangular fractal antenna with uc-ebg structure-2IAEME Publication
This document discusses the design and simulation of a self-affine rectangular fractal antenna with electromagnetic bandgap (EBG) structures. The antenna is designed on a substrate with a dielectric constant of 4.4 and thickness of 1.6mm. The basic rectangular patch antenna is modified through two iterations of fractal geometry to produce a multiband antenna. EBG structures are added surrounding the antenna. Simulation results show the antenna resonating at multiple frequencies with increased iteration, providing bandwidth enhancement and size reduction compared to the basic patch antenna. Good agreement is achieved between simulated and experimentally measured results.
Design and Analysis of Microstrip Antenna for CDMA Systems CommunicationIOSR Journals
This paper proposes a newly designed microstrip patch antennas (MSA) for wireless application
(CDMA Systems). The designed single antenna E-shaped patch antenna. Two parallel slots are in corporated
into the patch of a microstrip antenna to expand it bandwidth, and designed antenna operates in the frequency
range of 1.85 to 1.99 GHz. The antenna is designed using air as a dielectric substrate between the ground plane
and substrate patch antenna. IE3D is a full-wave electromagnetic simulator based on the method of moments
(MoM) technique. It has been widely used in the design of MICs, RFICs, patch antennas, wire antennas, and
other RF/wireless antennas. It can be used to calculate and plot the S parameters, VSWR, current distributions
as well as the radiation patterns. The results obtained for each patch were 2D and 3D view of patch, Directivity,
Gain, beam width and other such parameters, true and mapped 3D radiation pattern, and 2D polar radiation
pattern. The antenna successfully achieves the exhibit a broad impedance bandwidth of 27 % (at VSWR < 2)
with respect to the center frequency of 1.9 GHz is designed, fabricated, and finally measured on Spectrum
analyzer. The radiation pattern and directivity are also presented.. Gain maximum achievable is 3 dBi and good
return loss (S11 parameters) of -30 dB is achieved along with broadside radiation pattern.
Laplace Nonnegative Matrix Factorization with Application to Semi-supervised ...Hiroki_Tanji
1. Laplace Nonnegative Matrix Factorization (NMF) is a method that approximates observed nonnegative spectrograms using basis vectors and activation coefficients, minimizing a cost function based on the Laplace distribution.
2. The paper formulates NMF using complex Laplace distributions and derives update rules that guarantee convergence. This provides a novel statistical interpretation of NMF based on Itakura-Saito divergence.
3. Simulation results show that Laplace-NMF has favorable abilities for fitting complex-Laplace distributed data and performs better than other methods for semi-supervised audio denoising when noise follows a Laplace distribution.
This document discusses a study that used MATLAB curve fitting to determine the optical constants and thickness of tin oxide (SnO2) thin films. A transmission equation was customized in MATLAB and used to fit experimental transmittance data from SnO2 films. The curve fitting determined values for six parameters: refractive index, absorption coefficient, thickness, and constants related to dispersion models. The fitted curve closely matched the measured transmission curve, indicating the optical constants and thickness were accurately determined through this MATLAB curve fitting method.
Numerical ray tracing through a modified cladding fiber optic segment sensorsRadhi Chyad
1) The document investigates light transmission through an optical fiber with a modified cladding segment using 3D geometric optics modeling.
2) It analyzes how the intensity of transmitted light is affected by the refractive index and length of the modified cladding segment.
3) The modeling shows that if the modified cladding has a higher refractive index than the core, light transmission is very low due to partial reflection and losses. But if the modified cladding has a lower refractive index, transmission reaches saturation after a short segment length, making it suitable for sensor applications.
2009 measurement of focal ratio degradation in optical fibers used in astronomySiddartha Verma
1. The document describes a study that measured the focal ratio degradation (FRD) and throughput of optical fibers used in astronomy.
2. A simple experimental setup was used, involving a light source, lenses, and CCD camera to measure FRD for different input beam speeds. FRD causes the output beam to have a faster speed than the input.
3. The results showed throughput values of 85-90% for input f-numbers between 3-5. Quantifying FRD is important for optimizing astronomical instrumentation performance.
This document summarizes a research paper that presents a novel design of a complementary symmetry U-slot equilateral triangular microstrip antenna for pentaband operation between 1.83-8.73 GHz. The antenna is fabricated using a low-cost glass epoxy substrate and measures 8x5x0.16 cm3. It achieves a maximum bandwidth of 19.23% and peak gain of 2.19 dB. The antenna design and experimental results demonstrating its pentaband performance are described. Potential applications of the antenna include systems operating in DCS1900, IEEE 802.11a, HIPERLAN/2, and C band frequencies.
This document summarizes the design and simulation of an octal stepped microstrip patch antenna with a slotted section for wireless communications. The antenna was designed to operate at 4.52 GHz within the C-band range of 4-8 GHz, which is useful for satellite communications. The antenna structure and various design parameters were modeled and optimized using IE3D simulation software. The simulated results showed that Design 3 achieved the best impedance matching with a bandwidth of 3.26% at the target frequency. The proposed antenna design was concluded to be suitable for satellite communication and television applications due to its C-band operating range and optimized performance metrics obtained from simulation.
This document summarizes a research paper on the design and development of a complementary symmetry rectangular microstrip antenna for triple wideband operation. The antenna has dimensions of 80 x 50 x 1.6 mm3 and operates between 3.96-11.56 GHz with a maximum bandwidth of 29.45%. It is fabricated on a low-cost glass epoxy substrate using a simple photolithography process. Experimental results show that the antenna achieves triple wideband operation through the use of complementary E-slots on the patch and an H-slot on the ground plane. The antenna exhibits broadside radiation characteristics with a peak gain of 2.64 dB, making it suitable for applications in C and X-band communication systems.
Phase weighting of shaped pattern for base station antenna arrays marwaeng
The document discusses phase weighting techniques for synthesizing shaped radiation patterns in base station antenna arrays. It presents an algorithm that uses genetic optimization and particle swarm optimization to determine the phase weights needed to generate a desired shaped pattern. This is achieved by first using statistical sampling to get an initial approximation, then refining it with the optimization algorithms. Examples are given showing shaped patterns produced that meet requirements like low sidelobe levels and filled nulls. Phase-only weighting is preferred over amplitude weighting because it is easier to implement physically in the antenna feed network.
This document describes the simulation and design of a wideband E-shaped microstrip patch antenna that is conformed to a cylindrical surface. Simulation results using HFSS show that decreasing the substrate permittivity and increasing the substrate thickness can increase the antenna bandwidth. Bandwidths over 29 GHz were achieved with a thickness of 2.6 mm using lower permittivity substrates like RO3203 and Teflon. The compact size and ultra wideband performance of this cylindrical E-shaped patch antenna make it suitable for applications like high-speed wireless communication and avionics.
The document describes the design and simulation of a novel star-shaped fractal slot antenna. The antenna was modified from a triangular microstrip antenna into a star-shaped patch with fractal geometry. This increased the antenna's impedance bandwidth. Simulation results showed the antenna achieved a wide bandwidth of 56.67% from 4.8 GHz to 7.1 GHz, covering WLAN and X-band applications. Within this band, the antenna maintained stable radiation patterns and a gain ranging from 6.33 dBi to 10.02 dBi. Introducing a fractal iteration further improved the bandwidth and gain.
Design and Optimization of a High Gain Multiband Patch Antenna for Millimeter...IJECEIAES
The document describes the design and optimization of a quad-band patch antenna for millimeter wave applications between 27-51 GHz. The proposed antenna incorporates two symmetric "U" shaped slots and a central "I" shaped slot etched into the ground plane of a circular patch antenna. Simulation results show that the antenna resonates at four frequencies in the Ka, V and W bands. Tuning the dimensions and positions of the slots can shift the resonant frequencies. The optimized antenna design achieves high gain across the operating bands making it suitable for millimeter wave applications.
IRJET- Improving Performance of Circularly Polarized Patch Antenna by Varying...IRJET Journal
This document describes research on improving the performance of a circularly polarized patch antenna by varying the position of a stub. The antenna studied is a three-layer stacked microstrip patch antenna. Initially, the antenna without a stub showed poor return loss and axial ratio, indicating random polarization. A stub was then introduced at the radiating edge to generate circular polarization. By varying the stub position, the researchers measured parameters like return loss, axial ratio, and radiation efficiency. The best results were a return loss of -21.091 dB, axial ratio of 1.643 dB, and 100% antenna efficiency, indicating the design achieved circular polarization.
International Journal of Computational Engineering Research(IJCER)ijceronline
This document discusses using a triangular lattice electromagnetic bandgap (EBG) structure in the ground plane of a 2x2 triangular microstrip patch antenna array to improve its bandwidth. The EBG structure provides better antenna gain and a 110% increase in bandwidth compared to the antenna array without EBG. Keywords discussed include equilateral triangular microstrip patch antenna, antenna array, EBG, impedance bandwidth, and triangular lattice.
Radiation effect of fractal sierpinski square patch antennaIJECEIAES
Biological tissue interaction with Electromagnetic fields became one of the interesting studies in the last years. Wide variety wireless electronic devices are emerged in day to day life each providing a wireless connection for a certain service such as Global Positioning System, broadcasting systems, mobile communication systems, and networking. In this research article, fractal sierpinski square patch antenna is proposed and simulated to operate over L1 frequency range of 1.575 GHz for GPS applications using CST studio Suite where the proposed antenna has been investigated on Carpet shaped substrate made of Arlon 250 AD lossy. The dielectric constant equals to 2.5 and thickness of 1.6 mm. Thickness of patch is 0.6 mm. Also, the electromagnetic fields absorption on the human fingers is investigated where SAR levels are calculated for 0th, 1st, 2nd and 3rd iteration of the Fractal Sierpinski Square Patch Antenna. The results reported that the SAR limit of human finger tissue is enhanced with increasing the number of iteration: finger, human, tissue, GPS, SAR, absorption.
This document summarizes an adaptive traffic control system based on an embedded Linux board and image processing. The system uses a Raspberry Pi single board computer and OpenCV to process video frames from a digital camera mounted at an intersection. Vehicle counts on each road are determined using background subtraction and a Kalman filter algorithm. Based on the vehicle densities, different signal times are assigned to each road to improve traffic flow. The system also prioritizes emergency vehicles using GSM and GPS modules. Traffic data is stored on a web server to synchronize signals across intersections. The system aims to provide smoother traffic flow compared to fixed-time traffic signals.
Gain Comparison between NIFTY and Selected Stocks identified by SOM using Tec...IOSR Journals
This document discusses a study that uses self-organizing maps (SOM) and technical indicators to identify stocks with potential for investment gains. The study selects stocks and compares their returns over 1.5 months to the NIFTY index. The stocks identified using SOM and technical indicators performed 37.14% better than the NIFTY index over that period. The document provides background on technical analysis indicators like RSI, MACD, and OBV that were used in the analysis. It also describes how SOM can be used to classify stocks based on technical indicator values and select stocks that closely match the properties of the best performing class.
This document analyzes the polarization and transmission effects of antireflection coatings for silicon-on-insulator (SOI) material systems using simulation software. Without a coating, transmission of transverse magnetic (TM) polarized light is slightly higher than transverse electric (TE) polarized light. A single-layer antireflection coating is designed and optimized to increase average transmission by 19%, reducing the polarization effect. However, multilayer coatings did not further increase transmission over the optimized single layer. In conclusion, antireflection coatings can effectively reduce polarization dependence for SOI materials while improving overall light transmission.
Reduction of Mutual Coupling between Closely Spaced Microstrip Antennas Array...TELKOMNIKA JOURNAL
Reducing mutual coupling is a key research area in design of compact microstrip antennas
arrays. To minimize the overall size of the antennas arrays, the distance between them must be very
small, as a result a strong mutual coupling is appears. Periodic structures can help to design a low profile
of antennas arrays and enable to improve their performances by the suppression of surface waves
propagation in a given frequency range. This paper proposes a novel configuration of mushroom-like
electromagnetic band-gap (2D-EBG) structure created by microstrip technology placed between two
antennas arrays to reduce the mutual coupling more than -33.24dB. When 13×2 EBG structures are used,
the mutual coupling reduces to -59.36dB at the operation frequency 5.8GHz of the antennas arrays. A
26.12dB mutual coupling reduction is achieved, which proves that the surface wave is suppressed. The
proposed configuration is designed, optimized, and miniaturized by using electromagnetic software CST
Microwave Studio. The measured results show that there is a good agreement with the computed results.
Three complementary split spiral resonators (CSSRs) are used to reduce mutual coupling between two nearby microstrip patch antennas operating at 6.58 GHz. Simulation and measurement results show that using three vertically arranged CSSRs etched on the ground plane reduces the mutual coupling between the antennas by 23 dB. Characterization of the CSSR unit cell shows it behaves as a single negative metamaterial. The CSSRs block surface waves on the substrate to minimize coupling between the antenna elements while maintaining a low-profile compact structure with minimal impact on antenna performance.
This document summarizes a research paper that presents a dual open stub loaded square microstrip antenna (DOSMSA) for quad-band wireless communication applications. The DOSMSA consists of a square patch with two open stubs placed diagonally. Measurements show the DOSMSA operates over four bands from 2.88-8.55 GHz with gains up to 3.21 dB, compared to 0.8 dB for a basic square microstrip antenna. The DOSMSA design achieves quad-band operation using a simple stub loading technique while reducing the antenna's copper area by 7.8% compared to the basic design. The antenna has broadside radiation patterns and could enable applications in WLAN and WiMAX
Self affine rectangular fractal antenna with uc-ebg structure-2IAEME Publication
This document discusses the design and simulation of a self-affine rectangular fractal antenna with electromagnetic bandgap (EBG) structures. The antenna is designed on a substrate with a dielectric constant of 4.4 and thickness of 1.6mm. The basic rectangular patch antenna is modified through two iterations of fractal geometry to produce a multiband antenna. EBG structures are added surrounding the antenna. Simulation results show the antenna resonating at multiple frequencies with increased iteration, providing bandwidth enhancement and size reduction compared to the basic patch antenna. Good agreement is achieved between simulated and experimentally measured results.
Design and Analysis of Microstrip Antenna for CDMA Systems CommunicationIOSR Journals
This paper proposes a newly designed microstrip patch antennas (MSA) for wireless application
(CDMA Systems). The designed single antenna E-shaped patch antenna. Two parallel slots are in corporated
into the patch of a microstrip antenna to expand it bandwidth, and designed antenna operates in the frequency
range of 1.85 to 1.99 GHz. The antenna is designed using air as a dielectric substrate between the ground plane
and substrate patch antenna. IE3D is a full-wave electromagnetic simulator based on the method of moments
(MoM) technique. It has been widely used in the design of MICs, RFICs, patch antennas, wire antennas, and
other RF/wireless antennas. It can be used to calculate and plot the S parameters, VSWR, current distributions
as well as the radiation patterns. The results obtained for each patch were 2D and 3D view of patch, Directivity,
Gain, beam width and other such parameters, true and mapped 3D radiation pattern, and 2D polar radiation
pattern. The antenna successfully achieves the exhibit a broad impedance bandwidth of 27 % (at VSWR < 2)
with respect to the center frequency of 1.9 GHz is designed, fabricated, and finally measured on Spectrum
analyzer. The radiation pattern and directivity are also presented.. Gain maximum achievable is 3 dBi and good
return loss (S11 parameters) of -30 dB is achieved along with broadside radiation pattern.
Laplace Nonnegative Matrix Factorization with Application to Semi-supervised ...Hiroki_Tanji
1. Laplace Nonnegative Matrix Factorization (NMF) is a method that approximates observed nonnegative spectrograms using basis vectors and activation coefficients, minimizing a cost function based on the Laplace distribution.
2. The paper formulates NMF using complex Laplace distributions and derives update rules that guarantee convergence. This provides a novel statistical interpretation of NMF based on Itakura-Saito divergence.
3. Simulation results show that Laplace-NMF has favorable abilities for fitting complex-Laplace distributed data and performs better than other methods for semi-supervised audio denoising when noise follows a Laplace distribution.
This document discusses a study that used MATLAB curve fitting to determine the optical constants and thickness of tin oxide (SnO2) thin films. A transmission equation was customized in MATLAB and used to fit experimental transmittance data from SnO2 films. The curve fitting determined values for six parameters: refractive index, absorption coefficient, thickness, and constants related to dispersion models. The fitted curve closely matched the measured transmission curve, indicating the optical constants and thickness were accurately determined through this MATLAB curve fitting method.
Numerical ray tracing through a modified cladding fiber optic segment sensorsRadhi Chyad
1) The document investigates light transmission through an optical fiber with a modified cladding segment using 3D geometric optics modeling.
2) It analyzes how the intensity of transmitted light is affected by the refractive index and length of the modified cladding segment.
3) The modeling shows that if the modified cladding has a higher refractive index than the core, light transmission is very low due to partial reflection and losses. But if the modified cladding has a lower refractive index, transmission reaches saturation after a short segment length, making it suitable for sensor applications.
2009 measurement of focal ratio degradation in optical fibers used in astronomySiddartha Verma
1. The document describes a study that measured the focal ratio degradation (FRD) and throughput of optical fibers used in astronomy.
2. A simple experimental setup was used, involving a light source, lenses, and CCD camera to measure FRD for different input beam speeds. FRD causes the output beam to have a faster speed than the input.
3. The results showed throughput values of 85-90% for input f-numbers between 3-5. Quantifying FRD is important for optimizing astronomical instrumentation performance.
This document summarizes a research paper that presents a novel design of a complementary symmetry U-slot equilateral triangular microstrip antenna for pentaband operation between 1.83-8.73 GHz. The antenna is fabricated using a low-cost glass epoxy substrate and measures 8x5x0.16 cm3. It achieves a maximum bandwidth of 19.23% and peak gain of 2.19 dB. The antenna design and experimental results demonstrating its pentaband performance are described. Potential applications of the antenna include systems operating in DCS1900, IEEE 802.11a, HIPERLAN/2, and C band frequencies.
This document summarizes the design and simulation of an octal stepped microstrip patch antenna with a slotted section for wireless communications. The antenna was designed to operate at 4.52 GHz within the C-band range of 4-8 GHz, which is useful for satellite communications. The antenna structure and various design parameters were modeled and optimized using IE3D simulation software. The simulated results showed that Design 3 achieved the best impedance matching with a bandwidth of 3.26% at the target frequency. The proposed antenna design was concluded to be suitable for satellite communication and television applications due to its C-band operating range and optimized performance metrics obtained from simulation.
This document summarizes a research paper on the design and development of a complementary symmetry rectangular microstrip antenna for triple wideband operation. The antenna has dimensions of 80 x 50 x 1.6 mm3 and operates between 3.96-11.56 GHz with a maximum bandwidth of 29.45%. It is fabricated on a low-cost glass epoxy substrate using a simple photolithography process. Experimental results show that the antenna achieves triple wideband operation through the use of complementary E-slots on the patch and an H-slot on the ground plane. The antenna exhibits broadside radiation characteristics with a peak gain of 2.64 dB, making it suitable for applications in C and X-band communication systems.
Phase weighting of shaped pattern for base station antenna arrays marwaeng
The document discusses phase weighting techniques for synthesizing shaped radiation patterns in base station antenna arrays. It presents an algorithm that uses genetic optimization and particle swarm optimization to determine the phase weights needed to generate a desired shaped pattern. This is achieved by first using statistical sampling to get an initial approximation, then refining it with the optimization algorithms. Examples are given showing shaped patterns produced that meet requirements like low sidelobe levels and filled nulls. Phase-only weighting is preferred over amplitude weighting because it is easier to implement physically in the antenna feed network.
This document describes the simulation and design of a wideband E-shaped microstrip patch antenna that is conformed to a cylindrical surface. Simulation results using HFSS show that decreasing the substrate permittivity and increasing the substrate thickness can increase the antenna bandwidth. Bandwidths over 29 GHz were achieved with a thickness of 2.6 mm using lower permittivity substrates like RO3203 and Teflon. The compact size and ultra wideband performance of this cylindrical E-shaped patch antenna make it suitable for applications like high-speed wireless communication and avionics.
The document describes the design and simulation of a novel star-shaped fractal slot antenna. The antenna was modified from a triangular microstrip antenna into a star-shaped patch with fractal geometry. This increased the antenna's impedance bandwidth. Simulation results showed the antenna achieved a wide bandwidth of 56.67% from 4.8 GHz to 7.1 GHz, covering WLAN and X-band applications. Within this band, the antenna maintained stable radiation patterns and a gain ranging from 6.33 dBi to 10.02 dBi. Introducing a fractal iteration further improved the bandwidth and gain.
Design and Optimization of a High Gain Multiband Patch Antenna for Millimeter...IJECEIAES
The document describes the design and optimization of a quad-band patch antenna for millimeter wave applications between 27-51 GHz. The proposed antenna incorporates two symmetric "U" shaped slots and a central "I" shaped slot etched into the ground plane of a circular patch antenna. Simulation results show that the antenna resonates at four frequencies in the Ka, V and W bands. Tuning the dimensions and positions of the slots can shift the resonant frequencies. The optimized antenna design achieves high gain across the operating bands making it suitable for millimeter wave applications.
IRJET- Improving Performance of Circularly Polarized Patch Antenna by Varying...IRJET Journal
This document describes research on improving the performance of a circularly polarized patch antenna by varying the position of a stub. The antenna studied is a three-layer stacked microstrip patch antenna. Initially, the antenna without a stub showed poor return loss and axial ratio, indicating random polarization. A stub was then introduced at the radiating edge to generate circular polarization. By varying the stub position, the researchers measured parameters like return loss, axial ratio, and radiation efficiency. The best results were a return loss of -21.091 dB, axial ratio of 1.643 dB, and 100% antenna efficiency, indicating the design achieved circular polarization.
International Journal of Computational Engineering Research(IJCER)ijceronline
This document discusses using a triangular lattice electromagnetic bandgap (EBG) structure in the ground plane of a 2x2 triangular microstrip patch antenna array to improve its bandwidth. The EBG structure provides better antenna gain and a 110% increase in bandwidth compared to the antenna array without EBG. Keywords discussed include equilateral triangular microstrip patch antenna, antenna array, EBG, impedance bandwidth, and triangular lattice.
Radiation effect of fractal sierpinski square patch antennaIJECEIAES
Biological tissue interaction with Electromagnetic fields became one of the interesting studies in the last years. Wide variety wireless electronic devices are emerged in day to day life each providing a wireless connection for a certain service such as Global Positioning System, broadcasting systems, mobile communication systems, and networking. In this research article, fractal sierpinski square patch antenna is proposed and simulated to operate over L1 frequency range of 1.575 GHz for GPS applications using CST studio Suite where the proposed antenna has been investigated on Carpet shaped substrate made of Arlon 250 AD lossy. The dielectric constant equals to 2.5 and thickness of 1.6 mm. Thickness of patch is 0.6 mm. Also, the electromagnetic fields absorption on the human fingers is investigated where SAR levels are calculated for 0th, 1st, 2nd and 3rd iteration of the Fractal Sierpinski Square Patch Antenna. The results reported that the SAR limit of human finger tissue is enhanced with increasing the number of iteration: finger, human, tissue, GPS, SAR, absorption.
This document summarizes an adaptive traffic control system based on an embedded Linux board and image processing. The system uses a Raspberry Pi single board computer and OpenCV to process video frames from a digital camera mounted at an intersection. Vehicle counts on each road are determined using background subtraction and a Kalman filter algorithm. Based on the vehicle densities, different signal times are assigned to each road to improve traffic flow. The system also prioritizes emergency vehicles using GSM and GPS modules. Traffic data is stored on a web server to synchronize signals across intersections. The system aims to provide smoother traffic flow compared to fixed-time traffic signals.
Gain Comparison between NIFTY and Selected Stocks identified by SOM using Tec...IOSR Journals
This document discusses a study that uses self-organizing maps (SOM) and technical indicators to identify stocks with potential for investment gains. The study selects stocks and compares their returns over 1.5 months to the NIFTY index. The stocks identified using SOM and technical indicators performed 37.14% better than the NIFTY index over that period. The document provides background on technical analysis indicators like RSI, MACD, and OBV that were used in the analysis. It also describes how SOM can be used to classify stocks based on technical indicator values and select stocks that closely match the properties of the best performing class.
Android Malware: Study and analysis of malware for privacy leak in ad-hoc net...IOSR Journals
This document discusses analyzing Android malware that can leak privacy information in ad-hoc networks. It proposes using static and dynamic analysis methods to detect malware. In static analysis, reverse engineering is used to detect malicious code by decompiling Android app install files. In dynamic analysis, apps are run in an emulator to monitor their network behavior using tools like Snort. Destinations are then white-listed or blacklisted based on safety. The approach is compared to third party apps and is shown to also be effective at detecting malware that uses internet permissions to leak privacy data in small datasets.
Improvement of Congestion window and Link utilization of High Speed Protocols...IOSR Journals
This document summarizes a research paper that proposes using a k-nearest neighbors (k-NN) algorithm to help high-speed transport layer protocols like CUBIC better distinguish between packet drops due to network congestion versus other factors like noise. The k-NN algorithm would analyze patterns in packet drop history to classify new drops, helping protocols avoid unnecessary window size reductions when drops are not actually due to congestion. The document provides background on high-speed protocols, issues like underutilization from treating all drops as congestion, and how incorporating k-NN classification could improve protocols' performance in noisy network conditions.
Automated Surveillance System and Data CommunicationIOSR Journals
This document summarizes an automated video surveillance system that uses fuzzy color histograms (FCH) for background subtraction. It begins with an introduction to automated video surveillance and challenges with background subtraction. It then describes how the system works, including:
1) Calculating FCH features for each pixel using fuzzy membership values to color bins, which allows robustness to noise and quantization errors.
2) Comparing FCH features between current and background model frames using a similarity measure to classify each pixel as background or foreground.
3) Adaptively updating the background model at each pixel position over time using an online learning approach.
The key advantage of this approach is that the fuzzy color histograms allow efficient attenuation of
Implementation of Various Cryptosystem Using ChaosIOSR Journals
The document discusses implementing various cryptosystems using chaos. It first summarizes AES, IDEA, RC5, RSA, and ElGamal cryptographic algorithms. It then explains how chaos is applied to improve the security and speed of each algorithm. Chaos is used to generate new S-boxes for AES and mix the plaintext for IDEA, RC5 and ElGamal. The document claims that applying chaos in this way increases both security against attacks and encryption/decryption speeds compared to the original cryptographic algorithms.
A Low Power Delay Buffer Using Gated Driver TreeIOSR Journals
This document describes a low power delay buffer circuit that uses several techniques to reduce power consumption. It uses a ring counter addressing scheme with double-edge triggered flip-flops to reduce the clock frequency in half. It also proposes a novel gated clock driver tree to reduce activity on the clock distribution network. The gated driver tree idea is also applied to the input and output ports of the memory block to decrease loading and further reduce power. Simulation results show the effectiveness of these techniques in reducing power consumption for the delay buffer circuit.
IOSR Journal of Humanities and Social Science is an International Journal edited by International Organization of Scientific Research (IOSR).The Journal provides a common forum where all aspects of humanities and social sciences are presented. IOSR-JHSS publishes original papers, review papers, conceptual framework, analytical and simulation models, case studies, empirical research, technical notes etc.
An Automated Model to Detect Fake Profiles and botnets in Online Social Netwo...IOSR Journals
This document discusses an automated model for detecting fake profiles and botnets in online social networks. It begins with background on the prevalence of fake accounts, which can compromise user privacy and security. Next, it reviews related work on using data hiding techniques like steganography and watermarking to embed information in profile pictures in order to identify suspicious accounts. The proposed model aims to automatically detect fake profiles and botnets to replace current manual methods that are costly and labor-intensive.
Analysis of Stress Distribution in a Curved Structure Using Photoelastic and ...IOSR Journals
1. The document analyzes stress distribution in a curved structure subjected to uniaxial tension using photoelastic and finite element methods.
2. It introduces circular and elliptical stress relievers in the low stress region to reduce weight without affecting strength. The elliptical stress reliever with major axis normal to loading reduced stress intensity by 2% compared to the original structure.
3. Results from photoelastic experiments matched well with finite element analysis simulations. The experimental method provided precise stress values regardless of geometric complexity, while finite element analysis was less time consuming and helped optimize the stress reliever geometry.
Distributed Path Computation Using DIV AlgorithmIOSR Journals
This document summarizes research on distributed path computation algorithms that aim to prevent routing loops. It introduces the Distributed Path Computation with Intermediate Variables (DIV) algorithm, which can operate with any routing algorithm to guarantee loop-freedom. DIV generalizes previous loop-free algorithms and provably outperforms them by reducing synchronous updates and helping maintain paths during network changes. The document also reviews link-state routing, distance-vector routing, and existing loop-prevention techniques like the Diffusing Update Algorithm and Loop Free Invariance algorithms.
Role of soluble urokinase plasminogen activator receptor (suPAR) as prognosis...IOSR Journals
This document summarizes a study that examined the role of soluble urokinase plasminogen activator receptor (suPAR) as a prognostic marker for neonatal sepsis. The study measured suPAR levels in infants at risk of infection on days 0, 3, and 7 and compared them to a control group. It found that suPAR levels were higher in infants with sepsis and increased over time. suPAR levels on day 7 best predicted sepsis outcome, with higher levels associated with worsening sepsis and lower levels with improvement. The study concluded that suPAR could be used as a prognostic factor for neonatal sepsis.
This document summarizes a research paper that proposes a modified channel shortener filter (MCSF) to improve the spectral efficiency of OFDM systems. The MCSF exploits the null space of an underdetermined system of equations to provide multiple independent equivalent channels to the receiver. It is shown that the MCSF can achieve a higher spectral efficiency than conventional OFDM when the cyclic prefix length is significantly smaller than the channel delay spread. Simulation results demonstrate that the MCSF improves bit error rate performance and can provide up to 2dB gain compared to full cyclic prefix OFDM systems. The MCSF has the potential to reduce receiver complexity compared to existing channel shortening approaches.
A Novel Edge Detection Technique for Image Classification and AnalysisIOSR Journals
Abstract: The main aim of this project is to propose a new method for image segmentation. Image
Segmentation is concerned with splitting an image up into segments (also called regions or areas) that each
holds some property distinct from their neighbor. Simply, another word for the Object Detection is
“Segmentation “. Segmentation is divided into two types they are Supervised Segmentation and Unsupervised
Segmentation. Segmentation consists of three types of methods which are divided on the basis of threshold, edge
and region. Thresholding is a commonly used enhancement whose goal is to segment an image into object and
background. Edge-based segmentations rely on edges found in an image by edge detecting operators. Region
based segmentations basic idea is to divide an image into zones of maximum homogeneity, where homogeneity
is an important property of regions. Edge detection has been a field of fundamental importance in digital image
processing research. Edge can be defined as a pixels located at points where abrupt changes in gray level take
place in this paper one novel approach for edge detection in gray scale images, which is based on diagonal
pixels in 2*2 region of the image, is proposed. This method first uses a threshold value to segment the image
and binary image. And then the proposed edge detector. In order to validate the results, seven different
kinds of test images are considered to examine the versatility of the proposed edge detector. It has been
observed that the proposed edge detector works effectively for different gray scale digital images. The results of
this study are quite promising. In this project we proposed a new algorithm for edge Detection. The main
advantage of this algorithm is with running mask on the original image we can detect the edges in the images by
using the proposed scheme for edge detection.
Keywords: Edge detection, segmentation, thresholding.
The document presents closed-form expressions for determining the bending moments in two directions of a rectangular two-way slab under a concentrated load uniformly distributed over a defined area. Equations (16) and (17) provide the bending moment expressions for the short and long directions, respectively, as functions of the span ratio, load area dimensions ratios, and other geometric properties. Comparisons are made between results from the proposed analysis method, Egyptian code approximate method, Pigweed's theory, and finite element analysis, showing better accuracy of the proposed method and Pigweed's theory over the Egyptian code method.
Review On Google Android a Mobile PlatformIOSR Journals
This document reviews Google's Android mobile platform. It begins by providing background on the increasing popularity of smartphones and how Android was launched as an open-source platform to compete with other mobile platforms. It then describes the architecture of the Android software stack, including the Linux kernel, runtime environment, and application framework. Finally, it discusses the Android application execution process and how Android improved on the conventional mobile approach by giving all applications equal access to system resources.
This document discusses channel estimation in space-time trellis coding (STTC) for orthogonal frequency division multiplexing (OFDM) using multiple-input multiple-output (MIMO) systems with 4G networks. It presents the STTC-based MIMO-OFDM system model and describes how STTC achieves transmit diversity. It also discusses channel estimation and different decoding techniques for STTC codes, including minimum mean square error, zero forcing, and maximum likelihood decoding using the Viterbi algorithm. The goal is to achieve a low bit error rate and high signal-to-noise ratio to evaluate system performance.
A Robust Approach in Iris Recognition for Person AuthenticationIOSR Journals
The document describes a robust approach for iris recognition used for person authentication. It proposes using eight main stages: 1) scanning the iris image, 2) converting it to grayscale, 3) applying median filters to reduce noise, 4) detecting the pupil center, 5) using canny edge detection to identify iris and pupil edges, 6) determining the iris and pupil radii, 7) localizing the iris, and 8) unrolling the iris texture. It then uses k-means clustering to compare images and match them to authenticate individuals in a database. The approach aims to improve on previous iris recognition methods by more accurately detecting non-circular iris and pupil shapes.
Investigation of Reducing Process of Uneven Shade Problem In Case Of Compact ...IOSR Journals
This document investigates reducing uneven shade problems in compact single jersey cotton knit fabrics dyed with turquoise reactive dyes. Scanning electron microscopy shows that stripping and scouring combined increases fabric porosity compared to scouring alone, allowing better dye penetration. Color measurement testing finds that combining stripping and scouring results in more consistent dye absorption and less uneven shading than separate processes, with CMC ΔE values below 1 indicating acceptable color matches. In conclusion, performing stripping and scouring simultaneously on compact single jersey fabrics before dyeing with turquoise reduces uneven dyeing compared to conventional pretreatment methods.
IOSR Journal of Humanities and Social Science is an International Journal edited by International Organization of Scientific Research (IOSR).The Journal provides a common forum where all aspects of humanities and social sciences are presented. IOSR-JHSS publishes original papers, review papers, conceptual framework, analytical and simulation models, case studies, empirical research, technical notes etc.
This document summarizes research on using particle swarm optimization (PSO) to enhance the radiation pattern of a phase array antenna. It begins by introducing the problem of high sidelobes in phase array antenna patterns. It then provides background on phased array antennas and array pattern modeling. A 24-element linear array modeled in MATLAB is used as a case study. Standard PSO and a modified PSO algorithm are applied to optimize the current excitations and minimize the sidelobe levels. Simulation results show that both PSO approaches reduce sidelobes compared to uniform excitation, with the modified PSO performing better. Overall, the document presents research on using computational optimization methods to improve phase array antenna radiation patterns by controlling sidelobe levels
Elements Space and Amplitude Perturbation Using Genetic Algorithm for Antenna...CSCJournals
A simple and fast genetic algorithm (GA) developed to reduce the sidelobes in non-uniformly spaced linear antenna arrays. The proposed GA algorithm optimizes two vectors of variables to increase the Main lobe to Sidelobe power ratio (M/S) of array’s radiation pattern. The algorithm, in the first phase calculates the positions of the array elements and in the second phase, it manipulates the amplitude of excitation signals for each element. The simulations performed for 16 and 24 elements array structure. The results indicated that M/S improved in first phase from 13.2 to over 22.2dB meanwhile the half power beamwidth (HPBW) left almost unchanged. After element replacement, in the second phase, by using amplitude tapering further improvement up to 32dB was achieved. Also, the simulations shown that after element space perturbation, some antenna elements can be merged together without any performance degradation in radiation pattern in terms of gain and sidelobes level.
Synthesis of Optimized Asymmetrical Sum Patterns Using Conventional MethodIOSR Journals
Abstract: Sum patterns find applications in Radar for searching and ranging of the targets. A sum pattern with low sidelobe level is a desirable feature in these applications, in order to reduce EMI problems. Sum patterns with Asymmetrical sidelobe topography are considered, in applications where only certain angular regions of pattern are required to have low sidelobe level. Asymmetrical pattern characteristics can have lower beam widths for given design specifications as compared to symmetrical patterns. In view of this, a conventional method of synthesis is carried out in this paper, to produce asymmetrical sidelobe level patterns using discrete arrays. The effect of beam scanning on the pattern behavior is also analyzed for the above synthesized patterns. Keywords: sum pattern, asymmetrical sidelobe level, beam width, complex excitation weights, and discrete array.
Diagnosis of Faulty Sensors in Antenna Array using Hybrid Differential Evolut...IJECEIAES
In this work, differential evolution based compressive sensing technique for detection of faulty sensors in linear arrays has been presented. This algorithm starts from taking the linear measurements of the power pattern generated by the array under test. The difference between the collected compressive measurements and measured healthy array field pattern is minimized using a hybrid differential evolution (DE). In the proposed method, the slow convergence of DE based compressed sensing technique is accelerated with the help of parallel coordinate decent algorithm (PCD). The combination of DE with PCD makes the minimization faster and precise. Simulation results validate the performance to detect faulty sensors from a small number of measurements.
In the recent years the development in communication systems requires the development of low cost, minimal weight, low profile antennas that are capable of maintaining high performance over a wide spectrum of frequencies. This technological trend has focused much effort into the design of a micro strip patch antennas. Nowadays Evolutionary Computation has its growth to extent. Generally electromagnetic optimization problems generally involve a large number of parameters. Synthesis of non-uniform linear antenna arrays is one of the most important electromagnetic optimization problems of the current interest.
Synthesis of a Sparse 2D-Scanning Array using Particle Swarm Optimization for...Sivaranjan Goswami
The document describes a method for synthesizing a sparse 2D phased array antenna using particle swarm optimization to reduce side lobes. A 16x16 uniform rectangular array is used as a starting point. An artificial neural network is trained to map the excitation phase shifts to the main radiation angles. Particle swarm optimization is then used to determine a sparse array configuration and excitation weights that maintain low side lobe levels while removing half the elements. The results show the synthesized sparse array achieves similar side lobe performance to the original uniform array.
The document summarizes research on thinning semi-elliptical and quarter-elliptical antenna arrays using genetic algorithm optimization to reduce side-lobe levels. Key points:
1) Genetic algorithms were used to optimize thinning of semi-elliptical and quarter-elliptical arrays with uniform excitation and spacing to produce narrow beams without degrading performance.
2) Simulation results showed thinning using genetic algorithms reduced side-lobe levels of the arrays compared to fully populated arrays.
3) Maximum side-lobe levels, beamwidths, and other metrics were tabulated for various array sizes and geometries, indicating thinning effectively lowered side-lobes.
The document describes a hybrid method for simultaneously calculating the resonant frequencies of rectangular, circular, and triangular microstrip antennas (MSAs). The hybrid method combines an artificial neural network (ANN) and fuzzy inference system (FIS). The ANN is first used to compute resonant frequencies, and the fuzzy inference system corrects any inaccuracies in the ANN computations. The hybrid method allows for a single model to calculate resonant frequencies across different antenna geometries simultaneously. Results from the hybrid method show very good agreement with experimental data in the literature, improving upon results from previous single neural network models.
For high performance communication systems, Side Lobe Level (SLL) reduction and improved directivity are the goal of antenna designers. In the recent years, many optimization techniques of antenna design are occupying demanding place over the analytical techniques. Though they have contributed attractive solutions, it is often obvious to select one that meets the particular design need at hand. In this paper, an optimization technique called Self-adaptive Differential Evolution (SaDE) that can be able to learn and behave intelligently along with hyper beam forming is integrated to determine an optimal set of excitation weights in the design of EcAA. Non-uniform excitation weights of the individual array elements of EcAA are performed to obtain reduced SLL, high directivity and flexible radiation pattern. To evaluate the improved performance of the proposed SaDE optimized hyper beam, comparison are done with uniformly excited, SaDE without hyper beam and Genetic Algorithm (GA). In general, the proposed work of pattern synthesis has resulted in much better reduction of SLL and FNBW than both the uniformly excited and thinned EcAA. The results of this study clearly reveal that the SLL highly reduced at a very directive beamwidth.
Rabid Euclidean direction search algorithm for various adaptive array geometriesjournalBEEI
This document summarizes the Rabid Euclidean direction search (REDS) algorithm for adaptive beamforming in different antenna array geometries. The REDS algorithm is analyzed for linear, circular, and planar array configurations. Simulation results show that the REDS algorithm provides significant improvements over other algorithms, including faster convergence, lower mean square error, better interference reduction, and lower sidelobe levels. Specifically, the REDS algorithm cyclically searches and updates weights along individual Euclidean directions to minimize error, offering computational advantages over algorithms like least mean square and recursive least squares.
Particle Swarm Optimization with Constriction Factor and Inertia Weight Appro...IDES Editor
In this paper, an evolutionary optimization
technique, Particle Swarm Optimization with Constriction
Factor and Inertia Weight Approach (PSOCFIWA) is adopted
for the complex synthesis of three-ring Concentric Circular
Antenna Arrays (CCAA) with non-isotropic elements and
without and with central element feeding. It is shown that by
selection of a fitness function which controls more than one
parameter of the array pattern, and also by proper setting of
weight factors in fitness function, one can achieve very good
results. For each optimal design, optimal current excitation
weights and optimal radii are determined having the objective
of maximum Sidelobe Level (SLL) reduction. The extensive
computational results show that the CCAA designs having
central element feeding with non-isotropic elements yield
much more reduction in SLL as compared to the same not
having central element feeding. Moreover, the particular
CCAA containing 4, 6 and 8 number of elements in three
successive rings along with central element feeding yields
grand minimum SLL (-46.4 dB). Standard Particle Swarm
Optimization (PSO) is adopted to compare the results of the
PSOCFIWA algorithm.
Generation of Asymmetrical Difference Patterns from Continuous Line Source to...iosrjce
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
A hybrid method for designing fiber bragg gratings with right angled triangul...Andhika Pratama
This document proposes a hybrid method for designing fiber Bragg gratings (FBGs) with right-angled triangular spectra using the discrete layer peeling (DLP) approach and quantum-behaved particle swarm optimization (QPSO) algorithm. The DLP approach is used to generate an initial guess of the complex coupling coefficients. Then the QPSO technique optimizes the initial coefficients by minimizing the mean squared error between the target and computed reflectivity spectra. Simulation results show the method can design single and multi-channel right-angled triangular spectrum FBGs with linear edges and spectra consistent with the target.
performance analysis of different radiation pattern using genetic algorithmijtsrd
In most applications of antenna arrays, side lobe levels SLLs are commonly unwanted. Especially, the first side lobe level which determines maximum SLL is the main source of electromagnetic interference EMI , and hence, it should be lowered. In this thesis proposed a very simple and powerful method for the synthesis of linear array antenna. This method reduced the desired level of side lobe level SLL as well as to steer the main beam at different different angle. In this paper we draw the radiation pattern for N = 24 elements with main beam are shifted by 30° and the simulation result analysis by Matlab R2013a tool. Rahul Pandya | Praveen Kumar Patidar "Performance Analysis of Different Radiation Pattern using Genetic Algorithm" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-5 , August 2020, URL: https://www.ijtsrd.com/papers/ijtsrd33020.pdf Paper Url :https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/33020/performance-analysis-of-different-radiation-pattern-using-genetic-algorithm/rahul-pandya
Investigation on the Pattern Synthesis of Subarray Weights for Low EMI Applic...IOSRJECE
In modern radar applications, it is frequently required to produce sum and difference patterns sequentially. The sum pattern amplitude coefficients are obtained by using Dolph-Chebyshev synthesis method where as the difference pattern excitation coefficients will be optimized in this present work. For this purpose optimal group weights will be introduced to the different array elements to obtain any type of beam depending on the application. Optimization of excitation to the array elements is the main objective so in this process a subarray configuration is adopted. However, Differential Evolution Algorithm is applied for optimization method. The proposed method is reliable and accurate. It is superior to other methods in terms of convergence speed and robustness. Numerical and simulation results are presented.
Comparative and comprehensive study of linear antenna arrays’ synthesisIJECEIAES
In this paper, a comparative and comprehensive study of synthesizing linear antenna array (LAA) designs, is presented. Different desired objectives are considered in this paper; reducing the maximum sidelobe radiation pattern (i.e., pencil-beam pattern), controlling the first null beamwidth (FNBW), and imposing nulls at specific angles in some designs, which are accomplished by optimizing different array parameters (feed current amplitudes, feed current phase, and array elements positions). Three different optimization algorithms are proposed in order to achieve the wanted goals; grasshopper optimization algorithms (GOA), ant lion optimization (ALO), and a new hybrid optimization algorithm based on GOA and ALO. The obtained results show the effectiveness and robustness of the proposed algorithms to achieve the wanted targets. In most experiments, the proposed algorithms outperform other well-known optimization methods, such as; Biogeography based optimization (BBO), particle swarm optimization (PSO), firefly algorithm (FA), cuckoo search (CS) algorithm, genetic algorithm (GA), Taguchi method, self-adaptive differential evolution (SADE), modified spider monkey optimization (MSMO), symbiotic organisms search (SOS), enhanced firefly algorithm (EFA), bat flower pollination (BFP) and tabu search (TS) algorithm.
A Survey on Applications of Neural Networks and Genetic Algorithms in Fault D...IOSR Journals
This document summarizes research on using neural networks and genetic algorithms for fault diagnosis in antenna arrays. It provides background on smart antenna arrays and issues with traditional fault diagnosis methods. It then describes how neural networks like multilayer perceptrons and radial basis function networks can be trained to map damaged radiation patterns to faulty antenna locations. Genetic algorithms are also discussed as an approach to minimize differences between measured and expected radiation patterns. Various studies applying these methods to different antenna array configurations are summarized, demonstrating the effectiveness of neural networks and genetic algorithms for fast and accurate fault diagnosis in antenna arrays.
Bandwidth density optimization of misaligned optical interconnectsIJECEIAES
In this paper, the bandwidth density of misaligned free space optical interconnects (FSOIs) system with and without coding under a fixed bit error rate is considered. In particular, we study the effect of using error correction codes of various codeword lengths on the bandwidth density and misalignment tolerance of the FSOIs system in the presence of higher order modes. Moreover, the paper demonstrates the use of the fill factor of the detector array as a design parameter to optimize the bandwidth density of the communication. The numerical results demonstrate that the bandwidth density improves significantly with coding and the improvement is highly dependent on the used codeword length and code rate. In addition, the results clearly show the optimum fill factor values that achieve the maximum bandwidth density and misalignment tolerance of the system.
Segmentation Based Multilevel Wide Band Compression for SAR Images Using Coif...CSCJournals
Synthetic aperture radar (SAR) data represents a significant resource of information for a large variety of researchers. Thus, there is a strong interest in developing data encoding and decoding algorithms which can obtain higher compression ratios while keeping image quality to an acceptable level. In this work, results of different wavelet-based image compression and segmentation based wavelet image compression are assessed through controlled experiments on synthetic SAR images. The effects of dissimilar wavelet functions, number of decompositions are examined in order to find optimal family for SAR images. The choice of optimal wavelets in segmentation based wavelet image compression is coiflet for low frequency and high frequency component. The results presented here is a good reference for SAR application developers to choose the wavelet families and also it concludes that wavelets transform is rapid, robust and reliable tool for SAR image compression. Numerical results confirm the potency of this approach.
This document provides a technical review of secure banking using RSA and AES encryption methodologies. It discusses how RSA and AES are commonly used encryption standards for secure data transmission between ATMs and bank servers. The document first provides background on ATM security measures and risks of attacks. It then reviews related work analyzing encryption techniques. The document proposes using a one-time password in addition to a PIN for ATM authentication. It concludes that implementing encryption standards like RSA and AES can make transactions more secure and build trust in online banking.
This document analyzes the performance of various modulation schemes for achieving energy efficient communication over fading channels in wireless sensor networks. It finds that for long transmission distances, low-order modulations like BPSK are optimal due to their lower SNR requirements. However, as transmission distance decreases, higher-order modulations like 16-QAM and 64-QAM become more optimal since they can transmit more bits per symbol, outweighing their higher SNR needs. Simulations show lifetime extensions up to 550% are possible in short-range networks by using higher-order modulations instead of just BPSK. The optimal modulation depends on transmission distance and balancing the energy used by electronic components versus power amplifiers.
This document provides a review of mobility management techniques in vehicular ad hoc networks (VANETs). It discusses three modes of communication in VANETs: vehicle-to-infrastructure (V2I), vehicle-to-vehicle (V2V), and hybrid vehicle (HV) communication. For each communication mode, different mobility management schemes are required due to their unique characteristics. The document also discusses mobility management challenges in VANETs and outlines some open research issues in improving mobility management for seamless communication in these dynamic networks.
This document provides a review of different techniques for segmenting brain MRI images to detect tumors. It compares the K-means and Fuzzy C-means clustering algorithms. K-means is an exclusive clustering algorithm that groups data points into distinct clusters, while Fuzzy C-means is an overlapping clustering algorithm that allows data points to belong to multiple clusters. The document finds that Fuzzy C-means requires more time for brain tumor detection compared to other methods like hierarchical clustering or K-means. It also reviews related work applying these clustering algorithms to segment brain MRI images.
1) The document simulates and compares the performance of AODV and DSDV routing protocols in a mobile ad hoc network under three conditions: when users are fixed, when users move towards the base station, and when users move away from the base station.
2) The results show that both protocols have higher packet delivery and lower packet loss when users are either fixed or moving towards the base station, since signal strength is better in those scenarios. Performance degrades when users move away from the base station due to weaker signals.
3) AODV generally has better performance than DSDV, with higher throughput and packet delivery rates observed across the different user mobility conditions.
This document describes the design and implementation of 4-bit QPSK and 256-bit QAM modulation techniques using MATLAB. It compares the two techniques based on SNR, BER, and efficiency. The key steps of implementing each technique in MATLAB are outlined, including generating random bits, modulation, adding noise, and measuring BER. Simulation results show scatter plots and eye diagrams of the modulated signals. A table compares the results, showing that 256-bit QAM provides better performance than 4-bit QPSK. The document concludes that QAM modulation is more effective for digital transmission systems.
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D010212029
1. IOSR Journal of Electronics and Communication Engineering (IOSR-JECE)
e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 10, Issue 2, Ver.1 (Mar - Apr.2015), PP 20-29
www.iosrjournals.org
DOI: 10.9790/2834-10212029 www.iosrjournals.org 20 | Page
Comparision of Radiation Patterns for Thinned and Thicked
Arrays
D. Ramadevi1
, Dr.G.S.N.Raju2
1
Associate Professor, Department of ECE, MVGR College of Engineering, Vizianagaram
2
Professor in Department of ECE, Andhra University, Visakhapatnam
Abstract: It is possible to thin an array as well as to improve radiation pattern characteristics with an
appropriate spacing function. Array thinning plays a very important role in array synthesis. To analyze the
effect of thinning by considering a modulated spacing function. Using a specified spacing function, radiation
patterns are evaluated for different array lengths. It is found that the near-in-side lobe level is reduced for a
modulated spacing function and that the main beam width is found to remain constant. These advantages are
not found in the case of uniform spacing. Even after thinning the array, the modulated spacing function is found
to improve the overall radiation pattern characteristics.
Although some studies are made by the researchers on thinning, the effect of thickening is not reported
in the literature. In view of the above facts, intensive studies are carried out to investigate linear arrays with
thickening as well as thinning. The patterns are numerically evaluated for different arrays and the radiation
patterns are presented for different arrays. The investigations reveal that thickening has caused the reduction of
null to null beam width without deteriorating the side lobe levels. On the other hand thinning has resulted in
raising the side lobe levels as well as the beam width. If thinning is not carried out properly the resultant
radiation patterns contain even grating lobes.
I. Introduction
Hamici et al. [1] proposed a novel genetic algorithm called Immunity Genetic Algorithm (IGA) based
on stochastic crossover evolution to solve the synthesis problem of thinned arrays. A new expression of the
array factor for a specific number of elements N is expressed as a linear Discrete Cosine Transform (DCT).
Using IGA to generate thousands of array bit patterns and the DCT to compute the fitness function will result in
a very high speed computation compared to traditional computation techniques. This high performance allows
us to find a good approximation of the absolute minimum SLL of synthesized thinned arrays. Simulation results
of this novel array signal processing technique show the effectiveness for pattern synthesis with low SLL.
Basu et al. [2] have proposed the Inverse Fast Fourier technique (IFFT) combined with Artificial Bees
Colony (ABC) and Modified Particle Swarm Optimization (MPSO) which is used for the synthesis of thinned
mutually coupled linear array with uniform element spacing. Coupling effect has been taken into account via
induced EMF method and used to calculate the induced current on each element. Proposed technique is
employed to thin the array optimally to yield a minimum possible SLL and low return loss (RL). Performances
of both the algorithms are compared to show the effectiveness of each optimizer. Introduction of Inverse Fast
Fourier transform to calculate the array factor reduces the computation time significantly. The effectiveness of
the proposed technique is demonstrated for 100-element linear array and results are compared with that of a
fully populated array. This method is very popular for array designers.
A novel algorithm on beam pattern synthesis for linear aperiodic arrays with arbitrary geometrical
configuration was presented by Ling Cen et al. [3]. Linear aperiodic arrays are attractive for their advantages on
higher spatial resolution and lower side-lobe. However, the advantages are attained at the cost of solving a
complex non-linear optimization problem. In this paper, we explain the Improved Genetic Algorithm (IGA) that
simultaneously adjusts the weight coefficients and inter-sensor spacing of a linear aperiodic array in more details
and extend the investigations to include the effects of mutual coupling and the sensitivity of the Peak Sidelobe
Level (PSL) to steering angles. Numerical results show that the PSL of the synthesized beam pattern has been
successfully lowered with the IGA when compared with other techniques published in the literature. In addition,
the computational cost of our algorithm can be as low as 10% of that of a recently reported genetic algorithm
based synthesis method. The excellent performance of IGA makes it a promising optimization algorithm where
expensive cost functions are involved[10-12].
Intensive studies are carried out by Raju et al. [4-6] to investigate linear arrays with gradual thickening
as well as gradual thinning. The patterns are numerically evaluated for different arrays and the radiation patterns
are presented for different arrays. The investigations reveal that thickening has caused the reduction of null to
null beam width without deteriorating the side lobe levels. On the other hand thinning has resulted in raising the
2. Comparision of Radiation Patterns for Thinned and Thicked Arrays
DOI: 10.9790/2834-10212029 www.iosrjournals.org 21 | Page
side lobe levels as well as the beam width. If thinning is not carried out properly the resultant radiation patterns
contain even grating lobes.
The non-resonant spacing is proposed using a well-developed formula. This formula is useful for the
determination of space distribution for even and odd elements of the array. Introducing space distribution so
determined, the sector beams of specified width are realized. The radiation patterns are compared with those of
specified ones. The patterns are presented in u (sinθ) – domain.
Symmetric linear antenna arrays are described using Genetic Algorithm (GA) by Das etal. [6] Genetic
Algorithm has many advantages over other conventional optimization techniques. Real coded GA (RGA) is a
high performance evolutionary optimization algorithm. It is used in this paper to find optimum inter-element
spacing and excitation coefficients for the symmetric linear antenna array in order to minimize the maximum
relative sidelobe level (SLL) in the radiation pattern of the array for minimum possible First Null Beamwidth
(BWFN) increment.
Hsing Hsu et al. [7] described an innovative optimal radiation pattern of an adaptive linear array which
is derived by phase-only perturbations using a Particle Swarm Optimization (PSO) algorithm. An antenna array
is often made as an adaptive antenna. An optimal radiation pattern design for an adaptive antenna system is not
only to suppress interference by placing a null in the direction of the interfering source but also to derive the
maximum power pattern in the direction of the desired signal. The Signal Interference Ratio (SIR) can be
maximized. The PSO algorithm is a new methodology in this study area, which can handle adaptive radiation
pattern of antenna array. In this paper, an optimal radiation pattern of linear array is derived by phase-only
perturbations using a PSO algorithm.PSO algorithms will be stated and computed for this problem. Then, the
optimal solution can be derived, and simulation results are also presented [13-15].
Mandal et al. [8] proposed an evolutionary swarm intelligence technique; Craziness Particle Swarm
Optimization (CRPSO) is propounded for nullifying the radiation pattern of asymmetrical linear antenna array
in a particular direction. Multiple wide nulls are achieved by optimum perturbations of elements current
amplitude weights to have symmetric nulls about the main beam. Different numerical examples are presented to
illustrate the capability of CRPSO for pattern synthesis with a prescribed wide nulls locations and depths.
Further, the peak sidelobe levels are also reduces when compared to a uniformly excited array having equal
number of elements[9].
II. Formulation
Geometry of a 2N-element symmetric linear array along the x-axis
The free space far field pattern E(u) in X-Y plane along the X-axis is shown below and is
Given by Eq (1) for thinning
E u = 2 𝑎 𝑛 cos[(n − 0.5
N
𝑛=1
β d cos(u )]) (1)
u = sinθ
an =Amplitude excitation of the nth
element
If an =1 turn ON
If an =0 turn OFF
d=Inter element spacing= λ / 2
β =
2 π
λ
The free space far field pattern E(u)
for thickening is given by Eq (2)
(2)
a(x)=Amplitude excitation
u= sin θ
N
n
xuxlj n
exauE
1
)]()/2[(
)()(
3. Comparision of Radiation Patterns for Thinned and Thicked Arrays
DOI: 10.9790/2834-10212029 www.iosrjournals.org 22 | Page
x n = spacing=(2n – N -1) / N (ishmaru) [12]
Φ(x) = phase excitation =0
III. Results
Table1: Comparison of SLL and Beamwidth for thinned and thicked arrays
S.NO Number of Elements
Thinning Thickening
SLL in dB Beam width SLL Beam width
1 10 -30.4 0.2458 -19.0 0.328
2 20 -24.3 0.12 -18.8 0.18
3 30 -23.34 0.0792 -17 0.132
4 50 -22.5 0.04 -15.45 0.08
5 70 -19.19 0.04 -14.82 0.06
6 90 -18.28 0.02 -14.5 0.04
Table 2: Amplitude and spacing values for thinned and thicked arrays for N=10
S.NO
Amplitude distribution
for thinning
Spacing for thinning
Amplitude
distribution for
thickening
Spacing for
thickening
1 1 -2.5 1 -0.9000
2 1 -2 1,1 -0.700,-0.800
3 1 -1.5 1 -0.5000
4 1 -1 1 -0.3000
5 1 -0.5 1 -0.1000
6 1 0.5 1 0.1000
7 0 1 1 0.3000
8 0 1.5 1 0.5000
9 1 2 1,1 0.7000,0.8000
10 1 2.5 1 0.9000
-0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5
-40
-35
-30
-25
-20
-15
-10
-5
0
u
IE(u)IindB
thinning
thickening
Fig1: Radiation pattern for thinned and thicked array for N=10
Table 3: Amplitude and spacing values for thinned and thicked arrays for N=20
S.NO
Amplitude distribution for
thinning
Spacing for
thinning
Amplitude
distribution for
thickening
Spacing for
thickening
1 1 -5 1 -0.9500
2 1 -4.5 1,1 -0.8500,-0.9
3 1 -4 1 -0.7500
4 1 -3.5 1 -0.6500
5 1 -3 1 -0.5500
6 1 -2.5 1 -0.4500
7 1 -2 1 -0.3500
8 1 -1.5 1 -0.2500
9 1 -1 1 -0.1500
10 1 -0.5 1 -0.0500
11 1 0.5 1 0.0500
10. Comparision of Radiation Patterns for Thinned and Thicked Arrays
DOI: 10.9790/2834-10212029 www.iosrjournals.org 29 | Page
[12] R. Harrington, 1961. " Sidelobe reduction by nonuniform element spacing," IRE Transactions on Antennas and propagation, Vol. 9,
no. 2, pp. 187-192.
[13] Ishimaru, 1962. "Theory of unequally spaced arrays," IEEE Transactions on Antennas and Propagation, Vol. AP11, pp. 691–702,
Nov.
[14] D. G. Kurup, M. Himdi, and A. Rydberg, 2003. "Synthesis of uniform amplitude unequally spaced antenna arrays using the
differential evolution algorithm," IEEE Transactions on Antennas and Propagation, Vol. 51, no. 9 pp. 2210–2217.
[15] X. S. Yang, 2010. "Nature-Inspired metaheuristic algorithms," second edition, Luniver press.
[16] X. S, Yang, 2010. "Firefly algorithm, stochastic test functions and design optimizaiton," Int J Bio-Inspired Comput 2, 78-84.
Author’s Information
Ms.D.Ramadevi did her B.E in Electronics and Communication Engineering from Andhra
Universtiy in 1999. In 2006, she obtained her M.Tech (Instrumentation and control systems)
degree from J.N.T.Universty. She is having 15 years of teaching experience and presently
she is working as an Associate Professor in Department of ECE, MVGR College of
Engineering, Vizianagaram. She is also pursuing Ph.D in the Department of ECE,
J.N.T.University, Kakinda. She presented many papers in various national and international
conferences and journals of repute. Her research interests include Applied Electromagnetics,
Array Antennas and EMI/EMC. Ms. D.Ramadevi is the life member of IETE,SEMCE,ISOI.
Dr. G.S.N. Raju received his B.E., M.E. with distinction and first rank from Andhra
University and Ph.D. from IIT, Kharagpur. He is presently Vice-Chancellor, Andhra
University Visakhapatnam, India. He is in teaching and research for the last 30 years in
Andhra University. He guided 29 Ph.D.s in the fields of Antennas, Electro Magnetics,
EMI/EMC and Microwave, Radar Communications, Electronic circuits. Published about 300
technical papers in National/International Journals/Conference Journals and transactions. He
is the recipient of The State Best Teacher Award‟ from the Government of Andhra Pradesh
in 1999, ‟The Best Researcher Award‟ in 1994, ‟Prof. Aiya Memorial National IETE Award‟ for his best
Research guidance in 2008 and Dr. Sarvepalli Radhakrishnan Award for the Best Academician of the year 2007,
He was a visiting Professor in the University of Paderborn and also in the University Karlsruhe, Germany in
1994. At present he holds the positions of Vice-Chancellor, Andhra University, Visakhapatnam. He was Chief
Editor of National Journal of Electromagnetic Compatibility. Prof. Raju has published five textbooks Antennas
and Wave Propagation, Electromagnetic Field Theory and Transmission Lines, Electronics Devices and
Circuits, Microwave Engineering, Radar Engineering and Navigational Aids. Prof. Raju has been the best
faculty performer in Andhra University with the performance index of 99.37.