This paper presents a circuit analysis method for electromagnetic band gap (EBG) structures using transmission line theory. The EBG structure is modeled as a pure imaginary surface impedance. This allows calculating the reflection phase as a function of frequency and surface impedance. The analysis shows that the bandwidth of the EBG structure is defined by the frequency range where the reflection phase is between +90 and -90 degrees. The results of this analysis are validated by comparing with previously published full-wave simulations and good agreement is found.
Non-split Perfectly Matched Layer Boundary Conditions for Numerical Solution ...ijeljournal
This paper developed a non - split perfectly matched layer (PML) boundary condition (BC) for Finite Difference Time Domain (FDTD) simulation of electromagnetic wave propagation in 2D structure. The point source for electric field has been exploited for propagation of electromagnetic field through 2D structures to validate developed approach. The identity of resulted field distribution to that obtained for split PML BC have been demonstrated.
NON-SPLIT PERFECTLY MATCHED LAYER BOUNDARY CONDITIONS FOR NUMERICAL SOLUTION ...ijeljournal
This paper developed a non - split perfectly matched layer (PML) boundary condition (BC) for Finite Difference Time Domain (FDTD) simulation of electromagnetic wave propagation in 2D structure. The
point source for electric field has been exploited for propagation of electromagnetic field through 2D structures to validate developed approach. The identity of resulted field distribution to that obtained for split PML BC have been demonstrated.
This paper presents the effect of strain, temperature on Bragg wavelength of Fiber Bragg
Grating.Effect on reflectivity of Fiber Bragg Grating is analyzed by Keeping constant grating length and
increasing strain and temperature. The effect of Apodization functions on side lobe level and the reflectivity of
the reflection spectrum are studied using coupled mode theory. Apodization function have the best performance
in reducing side lobes, where side lobe oscillations are reduced. Simulation is carried out using Opti-grating
software.
A design of novel bendable Artificial Magnetic Conductor (AMC) structures has been presented in this paper in two selected of frequencies at 5G application. These designs started with a square patch shape and continued with the combination of circular and Jerusalem shape which resonate at a frequency of 18 GHz and 28 GHz. Details of the theory and the structures of AMCs are explained. The reflection phase, bandwidth, angular stability and dispersion diagram were studied. The simulated results plotted that the novel AMC has good bandwidth and size is reduced by 53 % and 55 % for both frequencies. Other than that, it is also proved that the novel AMC has a stable reflection phase and no band gap performs at the specific frequency. The good performances of this novel AMC make it useful in order to improve antenna’s performance.
Non-split Perfectly Matched Layer Boundary Conditions for Numerical Solution ...ijeljournal
This paper developed a non - split perfectly matched layer (PML) boundary condition (BC) for Finite Difference Time Domain (FDTD) simulation of electromagnetic wave propagation in 2D structure. The point source for electric field has been exploited for propagation of electromagnetic field through 2D structures to validate developed approach. The identity of resulted field distribution to that obtained for split PML BC have been demonstrated.
NON-SPLIT PERFECTLY MATCHED LAYER BOUNDARY CONDITIONS FOR NUMERICAL SOLUTION ...ijeljournal
This paper developed a non - split perfectly matched layer (PML) boundary condition (BC) for Finite Difference Time Domain (FDTD) simulation of electromagnetic wave propagation in 2D structure. The
point source for electric field has been exploited for propagation of electromagnetic field through 2D structures to validate developed approach. The identity of resulted field distribution to that obtained for split PML BC have been demonstrated.
This paper presents the effect of strain, temperature on Bragg wavelength of Fiber Bragg
Grating.Effect on reflectivity of Fiber Bragg Grating is analyzed by Keeping constant grating length and
increasing strain and temperature. The effect of Apodization functions on side lobe level and the reflectivity of
the reflection spectrum are studied using coupled mode theory. Apodization function have the best performance
in reducing side lobes, where side lobe oscillations are reduced. Simulation is carried out using Opti-grating
software.
A design of novel bendable Artificial Magnetic Conductor (AMC) structures has been presented in this paper in two selected of frequencies at 5G application. These designs started with a square patch shape and continued with the combination of circular and Jerusalem shape which resonate at a frequency of 18 GHz and 28 GHz. Details of the theory and the structures of AMCs are explained. The reflection phase, bandwidth, angular stability and dispersion diagram were studied. The simulated results plotted that the novel AMC has good bandwidth and size is reduced by 53 % and 55 % for both frequencies. Other than that, it is also proved that the novel AMC has a stable reflection phase and no band gap performs at the specific frequency. The good performances of this novel AMC make it useful in order to improve antenna’s performance.
Analysis of Highly Birefringent Photonic Crystal Fiber Employing Different Ge...ijsrd.com
In this paper we are proposed three different types of photonic crystal fibers and compared them for higher birefringence by using finite element method. Using elliptical holes instead of circular air holes we are getting high birefringence. We also obtained low dispersion for the same structure consist of a defect in the center design flexibility and high index contrast give a better birefringence in the range of 10-3 to 10-2.Also the characteristics of PCF are plotted for a range of wavelength
NOVEL BAND-REJECT FILTER DESIGN USING MULTILAYER BRAGG MIRROR AT 1550 NMcscpconf
Novel band-reject filter is proposed using multilayer Bragg mirror structure by computing reflection coefficient at 1550 nm wavelength for optical communication. Dimension of different
layers and material composition are modified to study the effect on rejection bandwidth, and no of layers is also varied for analyzing passband characteristics. GaN/AlxGa1-xN composiiton is taken as the choice for simulation purpose, carried out using propagation matrix method. Refractive indices of the materials are considered as function of bandgap, perating wavelength and material composition following Adachi’s model. One interesting result arises from the computation that band-reject filter may be converted into band-pass one by suitably varying ratio of thicknesses of unit cell, or by varying Al mole fraction. Simulated results can be utilised to design VCSEL mirror as optical transmitter.
Polarization insensitive switchable metamaterial absorber/reflector for X-ban...journalBEEI
A unit cell of squared shaped polarization-insensitive switchable metamaterial absorber/reflector is presented. The structure operates at 10.20 GHz under both absorber mode and reflector mode configurations. Copper wire bridging the gaps to form a circular shape structure were used as switches for operation mode selections. The structure was designed on an FR4 substrate, and the incidental wave angles were varied from 0 to 50 degrees. The structure demonstrated almost 100% absorption at resonance, 3.314 GHz percentage bandwidth at 80% as an absorber. On the other hand, as reflector, it demonstrated almost a 90% reflection and a usable bandwidth of 3.327 GHz.
Electronic bands structure and gap in mid-infrared detector InAs/GaSb type II...IJERA Editor
We present here theoretical study of the electronic bands structure E (d1) of InAs (d1=25 Å)/GaSb (d2=25 Å) type
II superlattice at 4.2 K performed in the envelope function formalism. We study the effect of d1 and the offset ,
between heavy holes bands edges of InAs and GaSb, on the band gap Eg (), at the center of the first Brillouin
zone, and the semiconductor-to-semimetal transition. Eg (, T) decreases from 288.7 meV at 4.2 K to 230 meV
at 300K. In the investigated temperature range, the cut-off wavelength 4.3 m ≤ c ≤ 5.4 m situates this sample
as mid-wavelength infrared detector (MWIR). Our results are in good agreement with the experimental data
realized by C. Cervera et al.
Design, Electrostatic and Eigen Frequency Analysis of Fixed– Fixed Beam MEMS ...IOSR Journals
The objective of this paper is to design of fixed–fixed MEMS Resonator. The beam of resonator is
made up of poly-silicon. This paper also presents the electrostatic and Eigen frequency analysis of MEMS
resonator. The resonator used in oscillator which can be fabricated on chip. It can also be used as Switch. The
size of crystal oscillator is in order of centimeter but the size of MEMS Resonator is in order of microns, so by
replace a crystal oscillator by MEMS Resonator, we can reduce the size of the system. The dc voltage is given to
the beam of resonator for electrostatic analysis & Eigen frequency analysis in different modes
Numerical Simulation and Efficiency Improvement of Solar Cell using Multi Lay...Dr. Amarjeet Singh
Efficiency improvement of solar cell has been
achieved using design and simulation of anti-reflecting
coating. Anti-Reflecting coating helps in deploying new
geometries shape for the evaluation of different methods to
provide for light trapping in all directions and enables full
space utilization when bringing together into device arrays.
Efficiency improvement strategies have been discussed using
efficient selection of modules and surface texturing using
TCAD tools. Significant improvement in yield and
minimization of losses was achieved using device simulation
and process simulation platform using silvaco tools. Multilayer anti reflecting coating has been designed which can be
studied to analyze the performance of system. It was observed
that multi-layer coating helps in improvement of available
current for similar light beam under simulation.
Structural, Electronic and Gamma Shielding Properties of BxAl1-xAsIJMERJOURNAL
ABSTRACT: The structural and electronic properties of BxAl1-xAs ternary alloys in the zincblende structure were systematically investigated by using the first principles calculations. The local density approximation was used for exchanged and correlation interaction. The calculated band gap bowing parameter was discovered to be mightily composition dependent of the Boron concentration. Additionally, we have calculated some gamma shielding parameters of BxAl1-xAs ternary alloys. Primarily, the values of mass attenuation coefficients (μρ) were calculated using WinXCom computer program and then these parameters were utilized to calculate the values of electron density (Nel) and effective atomic number (Zeff) in the wide energy range (1 keV - 100 GeV).
Design and Simulation of a Fractal Micro-TransformerIJERA Editor
Due to advancement in smart technologies, the issues like renewable energy integrations into the existing power
systems, reduced weight and size of power equipments is required. In this regard, this work is focused on the
study and design of fractal type micro-transformer for day-to-day applications. An air core transformer is
designed using finite element modeling. The obtained results showed far better implementation parameters in
comparison to the macro transformers.
Impact of Gouy-Chapman-Stern model on conventional ISFET sensitivity and stab...TELKOMNIKA JOURNAL
Utilizing Gouy-Chapman-Stern model can improve ISFET sensitivity and stability using Stern layer in direct contact with electrolyte in ISFET sensing window. However, this model remains a challenge in mathematical way, unless it’s re-applied using accurate simulation approaches. Here, we developed an approach using a commercial Silvaco TCAD to re-apply Gouy-Chapman-Stern model as ISFET sensing membrane to investigate its impact on sensitivity and stability of conventional ISFET. Sio2 material and high-k Ta2O5 material have been examined based on Gouy-Chapman and Gouy-Chapman-Stern models. Results shows that the ISFET sensitivity of SiO2 sensing membrane is improved from ~38 mV/pH to ~51 mV/pH and the VTH shift stability is also improved. Additionally, the results indicate that the sensitivity of Ta2O5 is 59.03 mV/pH that hit the Nearnst Limit 59.3 mV/pH and achieves good agreements with mathematical model and previous experimental results. In conclusion, this investigation introduces a real validation of previous mathematical models using commercial TCAD approach rather than expensive fabrication that paves the way for further analysis and optimization.
A MORPHOLOGICAL MULTIPHASE ACTIVE CONTOUR FOR VASCULAR SEGMENTATIONijbbjournal
This paper presents a morphological active contour ideal for vascular segmentation in biomedical images.
The unenhanced images of vessels and background are successfully segmented using a two-step
morphological active contour based upon Chan and Vese’s Active Contour without Edges. Using dilation
and erosion as an approximation of curve evolution, the contour provides an efficient, simple, and robust
alternative to solving partial differential equations used by traditional level-set Active Contour models. The
proposed method is demonstrated with segmented data set images and compared to results garnered from
multiphase Active Contour without Edges, morphological watershed, and Fuzzy C-means segmentations.
Design of Square Shaped Miniaturized Split Ring ResonatorsIJERA Editor
Microwaves are constantly experiencing changes for many years. Microwave circuits use microstrip lines because it allows easy integration of active and passive surface mount components and it is less costly. In addition to a large number of benefits, microstrip lines have some disadvantages such as narrow-band loss, interference and low efficiency. To overcome the disadvantages, metamaterials are introduced. The proposed work shows various concentric U-shaped multi-split ring resonators(SRRs) metamaterial structures with & without broadside coupling. As compared to the conventional split ring resonators , broadside coupled resonators shows decrease in the LC resonance frequency and provide an electrically small and easy-to-fabricate alternative to the present multi-band metamaterial structures. The multi-band magnetic resonator topologies are simulated using CST Microwave Studio (MWS) to compute and compare their electrical sizes. Different types of U-shaped structures with inner and outer rings of SRR are used to realize transmission spectra, resonant frequencies and electrical sizes. This topology has the flexibility of adjusting the resonance frequencies by changing the design parameters such as the gap width, metal width and inter-ring distances. The broadside-coupled multiple U-Shaped magnetic resonator topology is considered to be a useful contribution to multi-band metamaterial research applications.
A Front Surface Optimization Study for Photovoltaic ApplicationTELKOMNIKA JOURNAL
In this paper, we presented a possible front surface optical enhancement of Si solar cell by
optimizing the Antireflection (AR) and light trapping (LT) schemes. Conventional plasma enhanced
chemical vapor deposition (PECVD) and in house hot wire chemical vapor deposition (HWCVD) tool was
used to deposit Silicon Nitride (SiNX) layer and optimized at 668nm wavelength. This was followed by
surface texturing of random pyramids to further enhance the broadband reflectance of the front surface.
Broadband reflectance measurement using integrating sphere method showed achieved weighted average
reflectance (WAR) value of as low as 1.8% and 1.5%, when 85nm SiNX was deposited on top of random
pyramids structure using HWCVD and PECVD methods, respectively.
The metal-insulator-semiconductor (MIS) capacitor is the most useful device in the study of semiconductor surfaces. Since most practical problems in the reliability and stability of all semiconductor devices are intimately related to their surface conditions, an understanding of the surface physics with the help of MIS capacitors is of great importance to device operations.
Circular Patch Antenna Performance using EBG StructureIDES Editor
Electromagnetic Band-Gap (EBG) structures are a
popular and efficient technique for microwave applications.
EBG may be combined with microstrip antenna to increase
the diversity gain, the radiation efficiency and/or to suppress
surface waves, to reduce the side lobes of the radiation pattern
and to increase the bandwidth. In this paper, two different
structures will be presented and discussed, which involve: (1)
EBG structure fed by circular patch antenna, and (2) circular
patch antenna surrounded by one row of EBG structure. The
influence of the EBG structure on the radiation patterns is
investigated. The effect of the surface waves is also considered.
Finally, the reduction of the side lobes of the radiation pattern
to increase the bandwidth is presented.
A new hybrid method for mutual coupling minimization of an antenna array IJECEIAES
In this paper, a simultaneous application of geometric modification on patch elements and electromagnetic band gap (EBG) electromagnetic bandgap structures (hybrid method) has been suggested for 3.5 GHz wireless communication applications, to minimize the mutual coupling between radiating elements of microstrip array antennas. The suggested EBG slotted structure is composed of a one square ring and three squares placed on Rogers RO3010 having 10.2 and h=1.27 mm which presents respectively its dielectric constant and thickness. In this approach, the patch elements are geometrically modified, while also employing EBG structures, formed by four EBG cells, placed between the array elements at a near distance. The modification of the geometry of the antenna and the introduction of EBG reduces the mutual coupling of an array antenna with approximately 33 dB on the one hand and improves the antenna gain by approximately 0.43 dB on the other hand. Initially, slots are introduced in the patch geometry and then four EBG unit cells are inserted between two patches, operating at 3.5 GHz. The antenna array design parameters were optimized.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and 2D-EBG resembles like conventional plane reflector. The simulated results are presented.
Analysis of Highly Birefringent Photonic Crystal Fiber Employing Different Ge...ijsrd.com
In this paper we are proposed three different types of photonic crystal fibers and compared them for higher birefringence by using finite element method. Using elliptical holes instead of circular air holes we are getting high birefringence. We also obtained low dispersion for the same structure consist of a defect in the center design flexibility and high index contrast give a better birefringence in the range of 10-3 to 10-2.Also the characteristics of PCF are plotted for a range of wavelength
NOVEL BAND-REJECT FILTER DESIGN USING MULTILAYER BRAGG MIRROR AT 1550 NMcscpconf
Novel band-reject filter is proposed using multilayer Bragg mirror structure by computing reflection coefficient at 1550 nm wavelength for optical communication. Dimension of different
layers and material composition are modified to study the effect on rejection bandwidth, and no of layers is also varied for analyzing passband characteristics. GaN/AlxGa1-xN composiiton is taken as the choice for simulation purpose, carried out using propagation matrix method. Refractive indices of the materials are considered as function of bandgap, perating wavelength and material composition following Adachi’s model. One interesting result arises from the computation that band-reject filter may be converted into band-pass one by suitably varying ratio of thicknesses of unit cell, or by varying Al mole fraction. Simulated results can be utilised to design VCSEL mirror as optical transmitter.
Polarization insensitive switchable metamaterial absorber/reflector for X-ban...journalBEEI
A unit cell of squared shaped polarization-insensitive switchable metamaterial absorber/reflector is presented. The structure operates at 10.20 GHz under both absorber mode and reflector mode configurations. Copper wire bridging the gaps to form a circular shape structure were used as switches for operation mode selections. The structure was designed on an FR4 substrate, and the incidental wave angles were varied from 0 to 50 degrees. The structure demonstrated almost 100% absorption at resonance, 3.314 GHz percentage bandwidth at 80% as an absorber. On the other hand, as reflector, it demonstrated almost a 90% reflection and a usable bandwidth of 3.327 GHz.
Electronic bands structure and gap in mid-infrared detector InAs/GaSb type II...IJERA Editor
We present here theoretical study of the electronic bands structure E (d1) of InAs (d1=25 Å)/GaSb (d2=25 Å) type
II superlattice at 4.2 K performed in the envelope function formalism. We study the effect of d1 and the offset ,
between heavy holes bands edges of InAs and GaSb, on the band gap Eg (), at the center of the first Brillouin
zone, and the semiconductor-to-semimetal transition. Eg (, T) decreases from 288.7 meV at 4.2 K to 230 meV
at 300K. In the investigated temperature range, the cut-off wavelength 4.3 m ≤ c ≤ 5.4 m situates this sample
as mid-wavelength infrared detector (MWIR). Our results are in good agreement with the experimental data
realized by C. Cervera et al.
Design, Electrostatic and Eigen Frequency Analysis of Fixed– Fixed Beam MEMS ...IOSR Journals
The objective of this paper is to design of fixed–fixed MEMS Resonator. The beam of resonator is
made up of poly-silicon. This paper also presents the electrostatic and Eigen frequency analysis of MEMS
resonator. The resonator used in oscillator which can be fabricated on chip. It can also be used as Switch. The
size of crystal oscillator is in order of centimeter but the size of MEMS Resonator is in order of microns, so by
replace a crystal oscillator by MEMS Resonator, we can reduce the size of the system. The dc voltage is given to
the beam of resonator for electrostatic analysis & Eigen frequency analysis in different modes
Numerical Simulation and Efficiency Improvement of Solar Cell using Multi Lay...Dr. Amarjeet Singh
Efficiency improvement of solar cell has been
achieved using design and simulation of anti-reflecting
coating. Anti-Reflecting coating helps in deploying new
geometries shape for the evaluation of different methods to
provide for light trapping in all directions and enables full
space utilization when bringing together into device arrays.
Efficiency improvement strategies have been discussed using
efficient selection of modules and surface texturing using
TCAD tools. Significant improvement in yield and
minimization of losses was achieved using device simulation
and process simulation platform using silvaco tools. Multilayer anti reflecting coating has been designed which can be
studied to analyze the performance of system. It was observed
that multi-layer coating helps in improvement of available
current for similar light beam under simulation.
Structural, Electronic and Gamma Shielding Properties of BxAl1-xAsIJMERJOURNAL
ABSTRACT: The structural and electronic properties of BxAl1-xAs ternary alloys in the zincblende structure were systematically investigated by using the first principles calculations. The local density approximation was used for exchanged and correlation interaction. The calculated band gap bowing parameter was discovered to be mightily composition dependent of the Boron concentration. Additionally, we have calculated some gamma shielding parameters of BxAl1-xAs ternary alloys. Primarily, the values of mass attenuation coefficients (μρ) were calculated using WinXCom computer program and then these parameters were utilized to calculate the values of electron density (Nel) and effective atomic number (Zeff) in the wide energy range (1 keV - 100 GeV).
Design and Simulation of a Fractal Micro-TransformerIJERA Editor
Due to advancement in smart technologies, the issues like renewable energy integrations into the existing power
systems, reduced weight and size of power equipments is required. In this regard, this work is focused on the
study and design of fractal type micro-transformer for day-to-day applications. An air core transformer is
designed using finite element modeling. The obtained results showed far better implementation parameters in
comparison to the macro transformers.
Impact of Gouy-Chapman-Stern model on conventional ISFET sensitivity and stab...TELKOMNIKA JOURNAL
Utilizing Gouy-Chapman-Stern model can improve ISFET sensitivity and stability using Stern layer in direct contact with electrolyte in ISFET sensing window. However, this model remains a challenge in mathematical way, unless it’s re-applied using accurate simulation approaches. Here, we developed an approach using a commercial Silvaco TCAD to re-apply Gouy-Chapman-Stern model as ISFET sensing membrane to investigate its impact on sensitivity and stability of conventional ISFET. Sio2 material and high-k Ta2O5 material have been examined based on Gouy-Chapman and Gouy-Chapman-Stern models. Results shows that the ISFET sensitivity of SiO2 sensing membrane is improved from ~38 mV/pH to ~51 mV/pH and the VTH shift stability is also improved. Additionally, the results indicate that the sensitivity of Ta2O5 is 59.03 mV/pH that hit the Nearnst Limit 59.3 mV/pH and achieves good agreements with mathematical model and previous experimental results. In conclusion, this investigation introduces a real validation of previous mathematical models using commercial TCAD approach rather than expensive fabrication that paves the way for further analysis and optimization.
A MORPHOLOGICAL MULTIPHASE ACTIVE CONTOUR FOR VASCULAR SEGMENTATIONijbbjournal
This paper presents a morphological active contour ideal for vascular segmentation in biomedical images.
The unenhanced images of vessels and background are successfully segmented using a two-step
morphological active contour based upon Chan and Vese’s Active Contour without Edges. Using dilation
and erosion as an approximation of curve evolution, the contour provides an efficient, simple, and robust
alternative to solving partial differential equations used by traditional level-set Active Contour models. The
proposed method is demonstrated with segmented data set images and compared to results garnered from
multiphase Active Contour without Edges, morphological watershed, and Fuzzy C-means segmentations.
Design of Square Shaped Miniaturized Split Ring ResonatorsIJERA Editor
Microwaves are constantly experiencing changes for many years. Microwave circuits use microstrip lines because it allows easy integration of active and passive surface mount components and it is less costly. In addition to a large number of benefits, microstrip lines have some disadvantages such as narrow-band loss, interference and low efficiency. To overcome the disadvantages, metamaterials are introduced. The proposed work shows various concentric U-shaped multi-split ring resonators(SRRs) metamaterial structures with & without broadside coupling. As compared to the conventional split ring resonators , broadside coupled resonators shows decrease in the LC resonance frequency and provide an electrically small and easy-to-fabricate alternative to the present multi-band metamaterial structures. The multi-band magnetic resonator topologies are simulated using CST Microwave Studio (MWS) to compute and compare their electrical sizes. Different types of U-shaped structures with inner and outer rings of SRR are used to realize transmission spectra, resonant frequencies and electrical sizes. This topology has the flexibility of adjusting the resonance frequencies by changing the design parameters such as the gap width, metal width and inter-ring distances. The broadside-coupled multiple U-Shaped magnetic resonator topology is considered to be a useful contribution to multi-band metamaterial research applications.
A Front Surface Optimization Study for Photovoltaic ApplicationTELKOMNIKA JOURNAL
In this paper, we presented a possible front surface optical enhancement of Si solar cell by
optimizing the Antireflection (AR) and light trapping (LT) schemes. Conventional plasma enhanced
chemical vapor deposition (PECVD) and in house hot wire chemical vapor deposition (HWCVD) tool was
used to deposit Silicon Nitride (SiNX) layer and optimized at 668nm wavelength. This was followed by
surface texturing of random pyramids to further enhance the broadband reflectance of the front surface.
Broadband reflectance measurement using integrating sphere method showed achieved weighted average
reflectance (WAR) value of as low as 1.8% and 1.5%, when 85nm SiNX was deposited on top of random
pyramids structure using HWCVD and PECVD methods, respectively.
The metal-insulator-semiconductor (MIS) capacitor is the most useful device in the study of semiconductor surfaces. Since most practical problems in the reliability and stability of all semiconductor devices are intimately related to their surface conditions, an understanding of the surface physics with the help of MIS capacitors is of great importance to device operations.
Circular Patch Antenna Performance using EBG StructureIDES Editor
Electromagnetic Band-Gap (EBG) structures are a
popular and efficient technique for microwave applications.
EBG may be combined with microstrip antenna to increase
the diversity gain, the radiation efficiency and/or to suppress
surface waves, to reduce the side lobes of the radiation pattern
and to increase the bandwidth. In this paper, two different
structures will be presented and discussed, which involve: (1)
EBG structure fed by circular patch antenna, and (2) circular
patch antenna surrounded by one row of EBG structure. The
influence of the EBG structure on the radiation patterns is
investigated. The effect of the surface waves is also considered.
Finally, the reduction of the side lobes of the radiation pattern
to increase the bandwidth is presented.
A new hybrid method for mutual coupling minimization of an antenna array IJECEIAES
In this paper, a simultaneous application of geometric modification on patch elements and electromagnetic band gap (EBG) electromagnetic bandgap structures (hybrid method) has been suggested for 3.5 GHz wireless communication applications, to minimize the mutual coupling between radiating elements of microstrip array antennas. The suggested EBG slotted structure is composed of a one square ring and three squares placed on Rogers RO3010 having 10.2 and h=1.27 mm which presents respectively its dielectric constant and thickness. In this approach, the patch elements are geometrically modified, while also employing EBG structures, formed by four EBG cells, placed between the array elements at a near distance. The modification of the geometry of the antenna and the introduction of EBG reduces the mutual coupling of an array antenna with approximately 33 dB on the one hand and improves the antenna gain by approximately 0.43 dB on the other hand. Initially, slots are introduced in the patch geometry and then four EBG unit cells are inserted between two patches, operating at 3.5 GHz. The antenna array design parameters were optimized.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and 2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and
2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and
2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and 2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and 2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and 2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and
2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and 2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and 2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and 2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and
2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and 2D-EBG resembles like conventional plane reflector. The simulated results are presented.
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and
2D-EBG resembles like conventional plane reflector. The simulated results are presented.
Performance Improvement of Microstrip antenna using Fractal EBG structure and...iosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Performance Investigation and Enhancement of Fiber Bragg Gratingfor Efficient...IOSRJECE
In this paper, the performance of various windowfunctions for Fiber Bragg Grating Sensor (FBGS)is investigated and evaluated in order to get optimized reflection spectrum with high reflectivity and an efficient side lobe suppression for efficient sensing measurement applications.For this purpose, a wide range of design parameters which include grating length and refractive index modulation amplitudehas been chosen to evaluate the sensor design. The performances of the different windowfunctions have been then compared in terms of reflectivity, full width half maximum bandwidth (FWHM), and sidelobe level(SLL) so as to get the most suitable design parametersto be used for sensing measurement.The simulation results presented in this paper show the effectiveness of the optimizedFBG sensor, which can be further implemented for high performance sensing applications.
MODELING OF PLANAR METAMATERIAL STRUCTURE AND ITS EFFECTIVE PARAMETER EXTRACTIONIAEME Publication
This paper is about designing a Metamaterial structure and the Scattering Parameter Extraction Method that has become a prime tool for Metamaterial characterization so that there is a better understanding of relation between their configuration and associated properties of these materials in terms of negative permittivity and negative permeability to explore application potential. A 2D planar Metamaterial structure has been designed, fabricated and analyzed. It consists of conducting patches and meander lines on a dielectric substrate. Electromagnetic modeling was carried out using Finite Difference Time Domain method based simulation tool EMPIRE XCcel.
Dual Band to Wideband Pentagon-shaped Patch Antenna with Frequency Reconfigur...IJECEIAES
A dual band to wideband reconfigurable pentagon-shaped antenna with EBG unit cell is proposed. A minimal number of two EBG unit cell is deployed to realize frequency reconfigurable mechanism. By varying the state of the EBG the antenna is capable to change its dual band operation to wideband alternately. There are three cases that have been analysed, first case is the EBG incorporated antenna with ideal and second is with the active EBG. Subsequently, the third cases is the fabricated ideal EBG incorporated antenna. The dual band operation is at 1.8 GHz and 5.2 GHz while the wide band from 1.6 GHz to 2.37 GHz (770 MHz). The proposed reconfigurable antenna is suitable to be implemented for LTE (1.6 GHz), Wi-Fi (5.2 GHz), WiMAX (2.3 GHz) and cognitive radio application.
Dual Band to Wideband Pentagon-shaped Patch Antenna with Frequency Reconfigur...
21AM1D_01
1. Circuit Analysis of Electromagnetic Band Gap (EBG)
Structures
S. Palreddy2,3
, A.I. Zaghloul*1, 2
1
US Army Research Laboratory, Adelphi, MD 20783, USA
amir.zaghloul.civ@mail.mil
2
Virginia Tech, VA 24061, USA
amirz@vt.edu
3
Microwave Engineering Corporation, North Andover, MA 01845, USA
S_Palreddy@microwaveeng.com
Abstract—This paper presents a circuit analysis of
electromagnetic band gap structures (EBG). Microwave
transmission line theory is used to accurately analyze EBG
structures. The results of this analysis are compared with
previously published results, including more time-intensive full-
wave analysis result, and this analysis is validated. The analysis
applies to any type of EBG structure, including conventional
periodic EBGs and progressive-dimensions EBG with broadband
response.
I. INTRODUCTION
Electromagnetic band gap (EBG) structures are usually
periodic structures [1], [2], [3], [4]. EBG structures are
equivalent to a magnetic surface at the frequency of resonance
and thus have very high surface impedance; this makes a
tangential current element close to the EBG structure
equivalent to two current elements oriented in the same
direction without the EBG structure. This helps enhance the
forward radiation instead of completely cancelling it, as
indicated by the image theory. This makes the EBG structures
useful when mounting an antenna close to ground, provided
the antenna’s currents are parallel to the EBG surface.
EBG structures are equivalent to a tank circuit. Equations
(1) through (3) give the impedance, frequency of resonance
and bandwidth respectively of an EBG structure [1], [2], [3],
[4]. The bandwidth of the EBG structure is defined as the
band of frequencies where the reflection phase is between
+900
to –900
.
2
0
1
Lj
Zs
(1)
LC
1
0
(2)
C
L
BW
120
1
(3)
II. ANALYSIS
Assuming a plane wave incidence and using transmission
line theory, the reflection phase of the EBG structure can be
found. Transmission line theory is used to find the complex
reflection coefficient from the EBG surface and then the
reflection phase is found. The reflection coefficient from a
load ZL in a transmission line with a characteristic impedance
of Z0 is given by:
(4)
The reflection coefficient from a perfect electric conductor
(PEC) is -1. The reflection coefficient from a perfect magnetic
conductor (PMC) is +1. In both cases the magnitude is the
same, but the phase is different. So, to accurately analyse the
reflection phase, we need to come up with an approach that
does not change the magnitude of the reflection with
frequency, but changes the reflection phase with frequency.
How can this be done when the reflection coefficient has
difference of impedances in the numerator and sum of the
impedances in the denominator? We know that a complex
number and its complex conjugate have the same magnitude.
Free space has real impedance, so we need to model the EBG
structure as pure imaginary surface impedance. This is a good
approximation as EBG structures have low loss, which
implies the real part of the surface impedance is very small
compared to imaginary part. This analysis assumes that the
EBG structure is lossless. Let Zs be the surface impedance of
the EBG structure. The reflection coefficient and the
reflection phase can be calculated as:
(5)
0
0
ZZ
ZZ
L
L
jXZs
Copyright 2013 IEICE
Proceedings of the "2013 International Symposium on Electromagnetic Theory"
21AM1D-01
67
2. 0
0
s
s
Z
Z
(6)
1 (7)
0
1
tan2
x
(8)
The bandwidth of EBG structure is defined as the band
where the reflection phase is between +900
to -900
. Using this
with equation (8), we can find the required conditions on the
surface impedance.
00
9090
0
0
100
90tan218090
x
0
0
10
90tan2270
x
0
0
10
45tan135
x
11
0
X
00 X (9)
Equation (9) shows the required conditions to operate in the
bandwidth of the EBG. Figure 1 shows the relationship
between surface impedance and the reflection phase.
Fig. 1: Relationship between surface impedance and
reflection phase of EBG structure.
The band edges of the EBG structure, as shown in Figure 1,
are where the reflection phase is +900
(where the surface
0) and -900
(where the surface
impedance is equal to - 0 1 be the radian frequency
0
2
0
1
Lj
Zs
jXZs
2
0
1
1
0
1
L
0
1
2
0
1
1
L
0
1
2
02
1
2
0
L
(10)
-
2
0
2
2
0
1
L
0
2
2
0
2
1
L
0
2
2
02
2
2
0
L
(11)
Subtracting equations (10) and (11) we get:
21
0
2
02
1
2
2
L
021
0
2
0
1221
L
0
0
2
0
1221
L
1 2) cannot be zero, so the only possible solution
is:
0
2
0
12
L
Where
LC
1
0
Bandwidth =
C
LL
00
0
0
12 1
(12)
This analysis can be performed for any desired reflection
phase (using equation 8) to get the required conditions on the
surface impedance of the EBG structure. This paper uses the
reflection phase condition to be within +900
to -900
as this
condition is widely used in defining the bandwidth of EBG
structures, and these results are used in comparing the
previously published results. This analysis represents any
EBG structure as surface impedance and gives the required
conditions on the surface impedance to get the desired range
of reflection phase. Different types of EBG structures differ in
Proceedings of the "2013 International Symposium on Electromagnetic Theory"
68
3. the way they are implemented to get the desired surface
impedance. Thus this analysis applies to any EBG structure.
III. VALIDATION
We see that equation (12) agrees with the published
bandwidth given in equation (3), hence validating this analysis.
Using this analysis the reflection phase of a uniform EBG
structure is found using Matlab [6] and compared with the
published results in [5], which were obtained using
FDTD/PBC for the case where patch width is 3 mm, gap
between the patches is 0.5 mm, via height is 1 mm and the
relative permittivity of the board is 2.20. All the dimensions in
figures 2 through 5 are given as a fraction of wavelength at 12
GHz. To find the surface impedance, closed form equations
for the capacitance and inductance of the EBG structure are
used [4]. Figure 2 shows the comparison of the effect of the
patch width on the reflection phase, while Figure 3 shows the
comparison of the effect of the gap width on the reflection
phase. Figure 4 shows the comparison of the effect of the
substrate height on the reflection phase, while Figure 5 shows
the comparison of the effect of the substrate permittivity on
the reflection phase. Figures 2 through 5 show good
agreement and validates this analysis.
Fig. 2: Comparison of the effect of the patch width on the
reflection phase: results published in [5] using FDTD/PBC,
top, versus present analysis, bottom
Fig. 3: Comparison of the effect of the gap width on the
reflection phase: results published in [5] using FDTD/PBC,
top, versus present analysis, bottom
Fig. 4: Comparison of the effect of the substrate height on
the reflection phase: results published in [5] using FDTD/PBC,
top, versus present analysis, bottom
Proceedings of the "2013 International Symposium on Electromagnetic Theory"
69
4. Fig. 5: Comparison of the effect of the substrate
permittivity on the reflection phase: results published in [5]
using FDTD/PBC, top, versus present analysis, bottom
IV. CONCLUSION
EBG structures are helpful when mounting an antenna
near a ground plane; they are compact in size and have low
loss. This paper showed the analysis and characterization of
EBG structures using transmission line theory, and the
required conditions for a desired range of reflection phase are
calculated using a closed-form equation approach and the
results are compared with the published results and they agree
very well.
REFERENCES
[1] E. Yablonovitch, “Photonic band-gap structure,” , J. Opt.
Soc. Amer. B, Opt. Phys., vol.10,pp.283-295,Feb.1993.
[2] J.D. Joannopoulos, R. D. Meade and J.N. Winn,
“Photonic Crystals,” Princeton, NJ: Princeton Univ.
Press, 1995.
[3] D. Sievenpiper, L. Zhang, R. Broas, N. Alexopolous, and
E. Yablonovitch, “High-impedance frequency selective
surface with forbidden frequency band,” IEEE Trans.
Microwave Theory Tech. ,vol. 47, pp.2059-
2074,Nov.1999.
[4] D. Sievenpiper, “High-impedance Electromagnetic
Surfaces,” Ph. D. dissertation, Dep. Elect.Eng. Univ.
California at Los Angeles, Los Angeles, CA,1999.
[5] Fan Yang, Yahya Rahmat-Samii, “Electromagnetic Band
Gap Structures in Antenna Engineering”, Cambridge
University Press, 2009.
[6] Matlab: The Language of Technical Computing.
http://www.mathworks.com/
Proceedings of the "2013 International Symposium on Electromagnetic Theory"
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