The document summarizes research investigating the influence of infinite impedance flanges on the electromagnetic field of a plane waveguide. It presents the theoretical background, describing the problem setup and boundary conditions considered. It then outlines the solution method, detailing the integral equations derived to relate the unknown tangential electric field on the waveguide surface. Numerical results are presented analyzing the effects of impedance flanges and edge features on the electromagnetic field and radiation patterns.
Optimization of Surface Impedance for Reducing Surface Waves between AntennasIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Determination of Surface Currents on Circular Microstrip AntennaswailGodaymi1
This work aims to present a theoretical analysis of the electric and magnetic surface current densities of a circular
microstrip antenna (CMSA) as a body of revolution.
The rigorous analysis of these problems begins with the application of the equivalence principle, which introduces
an unknown electric current density on the conducting surface and both unknown equivalent electric and magnetic
surface current densities on the dielectric surface. These current densities satisfy the integral equations (IEs) obtained
by canceling the tangential components of the electric field on the conducting surface and enforcing the continuity
of the tangential components of the fields across the dielectric surface. The formulation of the radiation problems is
based on the combined field integral equation. This formulation is coupled with the method of moments (MoMs) as
a numerical solution for this equation.
The main stake is to detect a defective component or likely to become it during manufacture or inservice inspections, while improving control productivity. In this context, we develop a simulation tool of EC fastened structures testing, integrated to the ANSYS platform, aimed at conceiving testing methods, optimizing and qualifying it. The finite element method has been chosen, it is suitable for this type of problem. Various configurations have been considered for the inspection of a target with a defect in different thicknesses. Due to the impossibility to detect a defect located at a distance much greater than the skin depth δ. Indeed, the eddy currents amplitude are less than 95% of the maximum amplitude beyond a depth greater than 3 δ. We are interested in the detection of defects located at depths higher to three times the skin depth.
Effect of Piezoelectric Layer on Beam Parameters using Zigzag TheoryIDES Editor
An efficient higher order theory is presented for
static analysis of multilayered composite beams with
piezoelectric layers embedded or bonded to the surface, under
static electromechanical load. In this theory, the in-plane
displacement field is taken as a combination of a layer-wise
linear variation and a cubic variation across the thickness.
Transverse normal strains are neglected. The electric field is
also approximated as piecewise linear across the sub layers.
The displacement field is expressed in terms of only three
primary displacement variables excluding electric potential
variables by enforcing the conditions of zero transverse shear
stress at top and bottom of the beam and its continuity at layer
interfaces under general electromechanical loading. The effect
of thickness of the piezo-layer is observed for various loading
conditions. Also, the effect of beam lay-up on various
parameters is studied.
Research on Transformer Core Vibration under DC Bias Based on Multi-field Cou...inventionjournals
The Mathematical models for DC bias vibration analysis of the transformer core are developed in this paper. The model is combined into multi-physical field coupling modeling for vibration analysis of the transformer. By applying the primary voltage as excitation and under different DC bias, vibrations of the transformer core is simulated and analyzed.
Optimization of Surface Impedance for Reducing Surface Waves between AntennasIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Determination of Surface Currents on Circular Microstrip AntennaswailGodaymi1
This work aims to present a theoretical analysis of the electric and magnetic surface current densities of a circular
microstrip antenna (CMSA) as a body of revolution.
The rigorous analysis of these problems begins with the application of the equivalence principle, which introduces
an unknown electric current density on the conducting surface and both unknown equivalent electric and magnetic
surface current densities on the dielectric surface. These current densities satisfy the integral equations (IEs) obtained
by canceling the tangential components of the electric field on the conducting surface and enforcing the continuity
of the tangential components of the fields across the dielectric surface. The formulation of the radiation problems is
based on the combined field integral equation. This formulation is coupled with the method of moments (MoMs) as
a numerical solution for this equation.
The main stake is to detect a defective component or likely to become it during manufacture or inservice inspections, while improving control productivity. In this context, we develop a simulation tool of EC fastened structures testing, integrated to the ANSYS platform, aimed at conceiving testing methods, optimizing and qualifying it. The finite element method has been chosen, it is suitable for this type of problem. Various configurations have been considered for the inspection of a target with a defect in different thicknesses. Due to the impossibility to detect a defect located at a distance much greater than the skin depth δ. Indeed, the eddy currents amplitude are less than 95% of the maximum amplitude beyond a depth greater than 3 δ. We are interested in the detection of defects located at depths higher to three times the skin depth.
Effect of Piezoelectric Layer on Beam Parameters using Zigzag TheoryIDES Editor
An efficient higher order theory is presented for
static analysis of multilayered composite beams with
piezoelectric layers embedded or bonded to the surface, under
static electromechanical load. In this theory, the in-plane
displacement field is taken as a combination of a layer-wise
linear variation and a cubic variation across the thickness.
Transverse normal strains are neglected. The electric field is
also approximated as piecewise linear across the sub layers.
The displacement field is expressed in terms of only three
primary displacement variables excluding electric potential
variables by enforcing the conditions of zero transverse shear
stress at top and bottom of the beam and its continuity at layer
interfaces under general electromechanical loading. The effect
of thickness of the piezo-layer is observed for various loading
conditions. Also, the effect of beam lay-up on various
parameters is studied.
Research on Transformer Core Vibration under DC Bias Based on Multi-field Cou...inventionjournals
The Mathematical models for DC bias vibration analysis of the transformer core are developed in this paper. The model is combined into multi-physical field coupling modeling for vibration analysis of the transformer. By applying the primary voltage as excitation and under different DC bias, vibrations of the transformer core is simulated and analyzed.
Design of Non-Uniform Linear Antenna Arrays Using Dolph- Chebyshev and Binomi...IJERA Editor
This paper explores the analytical methods of synthesizing linear antenna arrays. The synthesis employed is
based on non-uniform methods. In particular, the Dolph-Chebyshev and binomial methods are used, so as to
improve the directivity of the array and to reduce the level of the secondary lobes by adjusting the geometrical
and electric parameters of the array. The radiation patterns, the directivity, and the array factors of the uniform
and the non-uniform methods are presented. It is shown that the Chebyshev arrays have better directivity than
binomial arrays for the same number of elements and separation distance, while binomial arrays have very low
side lobes compared with Chebyshev and uniform excitation arrays. Finally, numerical results of both methods
are analyzed and compared.
Spherical array of annular ring microstrip antennaswailGodaymi1
The paper discusses the analytical study of spherical arrays of annular ring microstrip antenna (ARMSA) elements excited by electric dipole. A new empirical relation for calculating the nonunifrom current amplitude distributions of these elements has been obtained. The relation contains the information about the current amplitude factor ()Δ of the antenna elements of the spherical array. The narrow beamwidth and low side lobe levels can be obtain by choosing appropriate the current amplitude factor. It is found that for current amplitude factor ()5.0=Δ the radiation pattern have narrow beamwidth and low side lobe levels compared with uniform current distribution array. Circular polarization is realized by this study depends on the spherical array geometry. By using appropriate phase of each antenna elements in spherical arrays, radiation pattern is steered without change of gain and beamwidth.
Study on Transmission Probabilities for Some Rectangular Potential Barriersijtsrd
In this research, we apply the time independent Schroedinger equation for a particle moving in one dimensional potential barrier of finite width and height. We study the two cases which corresponds to the particle energies being respectively larger and smaller than the potential barrier. Then, we calculate transmission coefficient T as a function of particle energy E for a potential barrier by changing the barrier height V0 and width L using Propagation Matrix Method. If we keep the barrier width constant and varying the height, we see that the passing limit is shifting towards the higher energies when barrier height is increased. If we keep the barrier height constant and change the barrier width, we see significance change in oscillations. Aye Than Kyae | Htay Yee | Thida Win | Aye Aye Myint | Kyaw Kyaw Naing "Study on Transmission Probabilities for Some Rectangular Potential Barriers" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26813.pdfPaper URL: https://www.ijtsrd.com/physics/other/26813/study-on-transmission-probabilities-for-some-rectangular-potential-barriers/aye-than-kyae
Bending and free vibration analysis of isotropic and composite beamsSayan Batabyal
The report mainly deals with the bending and free vibration analysis of beams using Finite Element Analysis. Softwares like ANSYS has been used and related theory discussed alongwith.
Shoe making has been an established art for at least 3500 years and the history of cowboy roots must begin somewhere there. They are mainly distinguished from shoes as extending above the ankle bone.
LEAN STARTUP PT.1 EEN PROBLEEM VINDEN DAT OPGELOST MAG WORDENMisha de Sterke
Door Misha de Sterke
van De Sterke Consultancy
Volg me via @mishadesterke
Meer informatie? Ga naar www.mishadesterke.nl of mail naar desterkeconsultancy@gmail.com
The Inception and Evolution of EIA and Environmental Clearance Process – Layi...IJERA Editor
EIA which stands for environmental impact assessment is a domain which encompasses almost all areas of
environmental engineering. EIA and environmental clearance (EC) are two things which MoEF, Govt. Of India
has mandated for many categories of project before their commissioning. Buildings with built up area of more
than 20000 metre square and townships with area more than 50 Ha or 150000 square metre of built up area
comes under it. A thorough report is made for the possible outcomes of the project (i.e..it‟s impact on
surrounding environment). If the impact is within the limits as specified by MoEF and SEAC, it is sent for
approval otherwise client is suggested to take corrective steps. Scope of the topic trespasses the boundaries of
green house gas emissions and global warming, water and energy crises, carbon emission and sequestration,
environmental pollution of various kind. It was EIA that brought in an element on environment in all projects. It
lead to eco friendly and sustainable construction techniques which paved way for the concept of green building.
Today EIA and environmental clearance are the only protectors of environment from the greeds of corporate
sector across globe. If applied with stringency it will usher us to an era where any advancement will be
apsolutely in tune with nature.This technical paper deals with the birth and growth of EIA in the world and in
India. It deals with the processes that are involved in carrying out EIA for a project and subsequently providing
it with environmental clearance. Also it emphasizes on how EIA led to a general awareness and paved way for
the concept of sustainable construction.
Isotherm Studies for Performance Evaluation of Functionalized Carbon Nanotube...IJERA Editor
Composite Nanofiltration membranes were fabricated by incorporating Carbon Nanotubes (CNT) and Polyvinylidene Fluoride (PVDF) membranes. A suspension was prepared by dispersing CNT (30 minutes of sonication) in Dimethyl Sulfoxide (DMSO) solvent for 0.5 mg/ml. This suspension after vacuum filtration dispersed over PVDF membrane of pore size 0.22μm. Excess DMSO was removed by washing using Ethanol followed by Deionized water. Normal and various functionalized (Hydroxyl (-OH), Carboxylic (-COOH), Amine (-NH2)) SWCNTs and MWCNTs were purchased and the CNT based polymer composite nanofiltration membranes were fabricated by vacuum filtration method at a uniform loading of 10mg/cm2. The experimental results were used to evaluate the TDS removal efficiency of the fabricated membrane modules, which are normal and functionalized (4 composites in both SW and MW combinations) CNT. The TDS removal efficiency of all the 8 composite membranes were observed under varied operating conditions viz., varying flow rate (100,150,200 and 250 ml/hr) and influent TDS (2500, 3000, 4000 and 5000 mg/l). The flux of the membrane is varied 200 to 500 lit/m2.hr. The Isotherm studies using the experimental data on Langmuir and Freundlich isotherm models validated the results of the experiment and are indicative of the role of adsorption of the functionalized CNT based polymer composite nanofiltration membranes which removing the TDS. The results showed that the amino functionalized SWCNTs based polymer composite (PVDF/SWCNTs) nanofiltration membranes can be used as an effective adsorbent for desalination due to their high adsorption capacity.
Design of Non-Uniform Linear Antenna Arrays Using Dolph- Chebyshev and Binomi...IJERA Editor
This paper explores the analytical methods of synthesizing linear antenna arrays. The synthesis employed is
based on non-uniform methods. In particular, the Dolph-Chebyshev and binomial methods are used, so as to
improve the directivity of the array and to reduce the level of the secondary lobes by adjusting the geometrical
and electric parameters of the array. The radiation patterns, the directivity, and the array factors of the uniform
and the non-uniform methods are presented. It is shown that the Chebyshev arrays have better directivity than
binomial arrays for the same number of elements and separation distance, while binomial arrays have very low
side lobes compared with Chebyshev and uniform excitation arrays. Finally, numerical results of both methods
are analyzed and compared.
Spherical array of annular ring microstrip antennaswailGodaymi1
The paper discusses the analytical study of spherical arrays of annular ring microstrip antenna (ARMSA) elements excited by electric dipole. A new empirical relation for calculating the nonunifrom current amplitude distributions of these elements has been obtained. The relation contains the information about the current amplitude factor ()Δ of the antenna elements of the spherical array. The narrow beamwidth and low side lobe levels can be obtain by choosing appropriate the current amplitude factor. It is found that for current amplitude factor ()5.0=Δ the radiation pattern have narrow beamwidth and low side lobe levels compared with uniform current distribution array. Circular polarization is realized by this study depends on the spherical array geometry. By using appropriate phase of each antenna elements in spherical arrays, radiation pattern is steered without change of gain and beamwidth.
Study on Transmission Probabilities for Some Rectangular Potential Barriersijtsrd
In this research, we apply the time independent Schroedinger equation for a particle moving in one dimensional potential barrier of finite width and height. We study the two cases which corresponds to the particle energies being respectively larger and smaller than the potential barrier. Then, we calculate transmission coefficient T as a function of particle energy E for a potential barrier by changing the barrier height V0 and width L using Propagation Matrix Method. If we keep the barrier width constant and varying the height, we see that the passing limit is shifting towards the higher energies when barrier height is increased. If we keep the barrier height constant and change the barrier width, we see significance change in oscillations. Aye Than Kyae | Htay Yee | Thida Win | Aye Aye Myint | Kyaw Kyaw Naing "Study on Transmission Probabilities for Some Rectangular Potential Barriers" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26813.pdfPaper URL: https://www.ijtsrd.com/physics/other/26813/study-on-transmission-probabilities-for-some-rectangular-potential-barriers/aye-than-kyae
Bending and free vibration analysis of isotropic and composite beamsSayan Batabyal
The report mainly deals with the bending and free vibration analysis of beams using Finite Element Analysis. Softwares like ANSYS has been used and related theory discussed alongwith.
Shoe making has been an established art for at least 3500 years and the history of cowboy roots must begin somewhere there. They are mainly distinguished from shoes as extending above the ankle bone.
LEAN STARTUP PT.1 EEN PROBLEEM VINDEN DAT OPGELOST MAG WORDENMisha de Sterke
Door Misha de Sterke
van De Sterke Consultancy
Volg me via @mishadesterke
Meer informatie? Ga naar www.mishadesterke.nl of mail naar desterkeconsultancy@gmail.com
The Inception and Evolution of EIA and Environmental Clearance Process – Layi...IJERA Editor
EIA which stands for environmental impact assessment is a domain which encompasses almost all areas of
environmental engineering. EIA and environmental clearance (EC) are two things which MoEF, Govt. Of India
has mandated for many categories of project before their commissioning. Buildings with built up area of more
than 20000 metre square and townships with area more than 50 Ha or 150000 square metre of built up area
comes under it. A thorough report is made for the possible outcomes of the project (i.e..it‟s impact on
surrounding environment). If the impact is within the limits as specified by MoEF and SEAC, it is sent for
approval otherwise client is suggested to take corrective steps. Scope of the topic trespasses the boundaries of
green house gas emissions and global warming, water and energy crises, carbon emission and sequestration,
environmental pollution of various kind. It was EIA that brought in an element on environment in all projects. It
lead to eco friendly and sustainable construction techniques which paved way for the concept of green building.
Today EIA and environmental clearance are the only protectors of environment from the greeds of corporate
sector across globe. If applied with stringency it will usher us to an era where any advancement will be
apsolutely in tune with nature.This technical paper deals with the birth and growth of EIA in the world and in
India. It deals with the processes that are involved in carrying out EIA for a project and subsequently providing
it with environmental clearance. Also it emphasizes on how EIA led to a general awareness and paved way for
the concept of sustainable construction.
Isotherm Studies for Performance Evaluation of Functionalized Carbon Nanotube...IJERA Editor
Composite Nanofiltration membranes were fabricated by incorporating Carbon Nanotubes (CNT) and Polyvinylidene Fluoride (PVDF) membranes. A suspension was prepared by dispersing CNT (30 minutes of sonication) in Dimethyl Sulfoxide (DMSO) solvent for 0.5 mg/ml. This suspension after vacuum filtration dispersed over PVDF membrane of pore size 0.22μm. Excess DMSO was removed by washing using Ethanol followed by Deionized water. Normal and various functionalized (Hydroxyl (-OH), Carboxylic (-COOH), Amine (-NH2)) SWCNTs and MWCNTs were purchased and the CNT based polymer composite nanofiltration membranes were fabricated by vacuum filtration method at a uniform loading of 10mg/cm2. The experimental results were used to evaluate the TDS removal efficiency of the fabricated membrane modules, which are normal and functionalized (4 composites in both SW and MW combinations) CNT. The TDS removal efficiency of all the 8 composite membranes were observed under varied operating conditions viz., varying flow rate (100,150,200 and 250 ml/hr) and influent TDS (2500, 3000, 4000 and 5000 mg/l). The flux of the membrane is varied 200 to 500 lit/m2.hr. The Isotherm studies using the experimental data on Langmuir and Freundlich isotherm models validated the results of the experiment and are indicative of the role of adsorption of the functionalized CNT based polymer composite nanofiltration membranes which removing the TDS. The results showed that the amino functionalized SWCNTs based polymer composite (PVDF/SWCNTs) nanofiltration membranes can be used as an effective adsorbent for desalination due to their high adsorption capacity.
Reliability Analysis of Slope Stability by Central Point MethodIJERA Editor
Given uncertainty and variability of the slope stability analysis parameter, the paper proceed from the perspective of probability theory and statistics based on the reliability theory. Through the central point method of reliability analysis, performance function about the reliability of slope stability analysis is established. What’s more, the central point method and conventional limit equilibrium methods do comparative analysis by calculation example. The approach’s numerical results are consistent with the traditional limit equilibrium method and meet the objective reality. The accuracy and practicality of reliability analysis is confirmed in order to provide reliability theory a scientific basis for the feasibility of slope stability analysis.
Discretizing of linear systems with time-delay Using method of Euler’s and Tu...IJERA Editor
Delays deteriorate the control performance and could destabilize the overall system in the theory of discretetime
signals and dynamic systems. Whenever a computer is used in measurement, signal processing or control
applications, the data as seen from the computer and systems involved are naturally discrete-time because a
computer executes program code at discrete points of time. Theory of discrete-time dynamic signals and systems
is useful in design and analysis of control systems, signal filters, state estimators and model estimation from
time-series of process data system identification. In this paper, a new approximated discretization method and
digital design for control systems with delays is proposed. System is transformed to a discrete-time model with
time delays. To implement the digital modeling, we used the z-transfer functions matrix which is a useful model
type of discrete-time systems, being analogous to the Laplace-transform for continuous-time systems. The most
important use of the z-transform is for defining z-transfer functions matrix is employed to obtain an extended
discrete-time. The proposed method can closely approximate the step response of the original continuous timedelayed
control system by choosing various of energy loss level. Illustrative example is simulated to demonstrate
the effectiveness of the developed method.\
A review on TIG welding for optimizing process parameters on dissimilar jointsIJERA Editor
Tungsten Inert Gas Welding (TIG) is relatively high strength welding technique. This technique are mostly used in fabrication and other industries to join the either similar or dissimilar materials. In particular, it can be used to join high-quality strength of metal and alloys.In this paper we discuss abouttheTungsten Inert Gas welding of joining heat treatableof stainless steel and mild steel.These welded joints have higher tensile strength to weight ratio and finer micro structure. Tungsten Inert Gas Weldingofdissimilar material such as stainless steel and mild steel have the potential to hold good mechanical and metallurgical properties.
A Review and study of the design technique of Microstrip Patch Antenna Techno...IJERA Editor
In this paper,study and survey of microstrip antenna elements is presented, with emphasis on theoretical and
practical design techniques and material used, as previous study have been proved that material used play
significant role in the performance such as gain ,directivity ,frequency of radiation Available substrate materials
are reviewed along with the relation between dielectric constant tolerance and resonant frequency of microstrip
patches. Several theoretical analysis techniques are summarized. Practical procedures are given for both
standard rectangular and circular patches. The quality, bandwidth, and efficiency factors of typical patch designs
are discussed.
A Brief Study of Video Encryption AlgorithmsIJERA Editor
Video is a set of images .Video encryption is encrypting those set of images .Thus video encryption is simply hiding your video from prying eyes .Video monitoring has always been in concerned .Multimedia security is very important for multimedia commerce on Internet such as video on demand and Real time video multicast. There are various video encryption algorithm. All have some kind of weakness .In this paper classification of various existing algorithm, its advantages and disadvantages is discussed.
Analysing The Composite Structure Of Riverted ,Hybrid And Bonded JointsIJERA Editor
Composite materials have been widely used as structural elements in aircraft structures due to their superior
properties. Aircraft structure is a huge assembly of skins, spars, frames etc. The structure consists of an
assembly of sub-structures properly arranged and connected to form a load transmission path. Such load
transmission path is achieved using joints. Joints constitute the weakest zones in the structure. Failure may occur
due to various reasons such as stress concentrations, excessive deflections etc. or a combination of these.
Therefore, to utilize the full potential of composite materials, the strength and stress distribution in the joints has
to be understood so that suitable configuration can be chosen for various applications
Radiation patterns account of a circular microstrip antenna loaded two annularwailGodaymi1
In this paper, theoretical study of circular microstrip antenna loaded two annular (CMSAL2AR) and calculation
of the radiation pattern using principle equivalence with moment of method formulation of electromagnetic
radiation in this these based on the bodies of revolution (BoR), which are generated by revolution a planar curve
about an axis called axis of symmetry to solving the electric fields integral equation (EFIE) and magnetic field
integral equation (MFIE). To find an unknown electric current density on the conductor surface ,and both
unknowns electric and magnetic density current on the dielectric surface which are responsible for the
generation of far fields radiation in the space for the components (Eθ ,Eφ) ,the surface currents was represented
by a set of basis functions that give the Fourier series because the body has a circular symmetry property and
then select a set of weighted functions to find a linear system by using Galerkin method which requires that the
weighted functions are equal to the complex conjugate of the current ( ) * W = J .from radiation pattern
calculated the Directive gain can be utilized to the directive gain increased to (G= 21.30 dB) when
( 0.015λ 1 = g R ) for the ratio of (Rab= 5.5), and bandwidth has been better (BW%= 19.9%) when
( 0.01λ 1 = g R ) for the ratio (Rab= 6.5) .
High impedance surface_his_ris_amc_nurmerical_analytical_analysis利 金
Features of an AMC such as dispersion diagram and reflection phase are discussed numerically and analytically, along with their experimental set up. Parametric study on polarization (TE and TM,substrate thickness and dielectric constant and unit cell size and spacing is carried out. Their design equations are included from different references.
On the Vibration Characteristicsof Electrostatically Actuated Micro\nanoReson...IJERDJOURNAL
Electrostatic actuation is one of the most prevalent methods of excitation and measurement in micron to Nano scale resonators. Heretofore, in the dynamical behavior analyses of these systems, the resonating beam has been assumed to be perfect conductor which is obviously an approximation. In this paper, effect of electrical resistivity on the vibrational response of these systems including natural frequency and damping, is investigated. The governing coupled nonlinear partial differential equations of motion are extracted and a finite element formulationby developinga new electromechanical element is presented. Calculated natural frequencies are compared with experimental measurements and a closer agreement is achieved in comparison with previousfindings. Results indicate there is a jump in frequency and damping of the system at a critical resistivity. As system size is decreased and applied voltage approaches toward pull-in voltage, electrical resistivity fully dominates the response nature of the system.
Numerical studies of the radiation patterns of resistively loaded dipolesLeonid Krinitsky
The far field radiation patterns of finite-size resistively loaded horizontal electric dipoles lying on a low-loss dielectric half-space are computed. The patterns are a superposition of the solutions for transient infinitesimal dipole elements, where the transient waveform for each element is synthesized from the exact steady-state solution. The current excitation for each dipole element is a half cycle of a sine squared waveform that propagates along the line of elements at a speed that can be varied. No reflections from the antenna ends are assumed. The time duration of the current half cycle governs the full period of the dominant part of the transient radiated waveform. The amplitude of the dipole excitation current is determined by a cosine distribution that accurately simulates the resistive loading. The transient radiation patterns differ from those of a steady-state dipole mainly by being more narrow in the E-plane, as is true for a finite-size steady-state dipole radiating in air. In addition, the far field waveforms are slightly distorted in directions off vertical in the E-plane. Two-way power radiation patterns are presented for both conductive and non-conductive dielectric media in a footprint mode, i.e. the power response to an isotropic point scatterer on a subsurface flat plane. The radar footprint in a conductive dielectric shows very narrow beamwidth due to the added conductive attenuation along the longer paths off the vertical direction. Field tests in water and glacial ice and laboratory observations show good agreement with the E-plane model results but suggest that the H-plane directivity is strongly affected by the separation between transmit and receive antennas and by the range.
Characteristic equation and properties of electron waves in periodic structuresVictor Solntsev
The difference theory of excitation of periodic waveguides is used to derive the characteristic equation for electron waves formed during interaction of an electron flow with forward and counter-propagating electromagnetic waves of periodic waveguides (slowﱹwave structures). The derived characteristic equation describes interaction of electrons and waves in passbands and stopbands of periodic waveguides and contains known solutions for “smooth” slow-wave structures and resonator slow-wave structures near cutoff frequencies as particular cases. Several analytical solutions allowing comparison of amplification and propagation properties of electron waves inside and at the edges of passbands and stopbands of periodic waveguides are found.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
The Influence Of Infinite Impedance Flanges On The Electromagnetic Field Of A Plane Waveguide
1. J François D. Essiben et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 2, ( Part -2) February 2015, pp.104-110
www.ijera.com 104 | P a g e
The Influence Of Infinite Impedance Flanges On The
Electromagnetic Field Of A Plane Waveguide
Jean-François D. Essiben1
, Eric R. Hedin2
, and Yong S. Joe2
1
Department of Electrical Engineering, Advanced Teachers’ College for Technical Education University of
Douala, B.P. 1872, Douala-Cameroon
2
Center for Computational Nanoscience, Department of Physics and Astronomy, Ball State University Muncie,
IN, 47306, USA
ABSTRACT
The problem of analysis of the electromagnetic field behaviour from the open end of the parallel-plate
waveguide with infinite impedance flanges is theoretically investigated. The case with the absence of impedance
flanges is also considered. Furthermore, we take into account particular features of the waveguide edges. The
effects of the impedance flanges and the edge features on the electromagnetic field and the radiation patterns of a
plane waveguide with flanges are demonstrated. The method of moments (MoM) technique which was used to
solve the integral equations is presented along with the numerical results.
Keywords - Impedance, method of moment, radiation pattern, waveguide.
I. INTRODUCTION
To change the characteristics of radar location of
military equipment, radar absorbing materials and
coverings are effective when applied to mobile
installations, as well as to those on which antennas
systems are placed [1]. From the point of view of
electrodynamics, the usage of radar absorbing
materials and coverings amounts to changing the
distribution of surface currents, by means of the
management of surface wave amplitudes formed on
the object by the attenuating structures. However,
the redistribution of fields on the surface of the object
leads to variations not only in the scattering
characteristics of the object but also in its radiation
characteristics, in relation to antennas located nearby.
Methods are known for decreasing the
interaction between antennas using an alteration of
amplitude and phase distributions on certain surfaces.
Among the accepted measures used to decrease the
coupling between antennas are mutual shielding of
antennas and placement of additional screens across
the interface. In the case of near-omnidirectional
antennas, two groups of additional measures are
applied: radio-wave absorbing materials, and surface
decoupling devices. Since the waveguide as a
radiating element finds much usage in antenna
techniques, the analysis of the radiation
characteristics of such a device represents a field of
significant scientific interest [2]. Furthermore, the
analysis of the impedance influence on the
electromagnetic field behaviour across the open-end
of the plane waveguide is one of the major applied
problems of electrodynamics. It is also known [3]
that varying the reactive resistance allows one to
change the phase field re-radiated by the structure,
which consequently facilitates managing the re-
radiated field.
For an approximate solution to the analysis of
electromagnetic wave radiation from a semi-infinite
waveguide with ideally conducting flanges, the
method of integral equations is often used [1]. It is
necessary to generalize this familiar approach when
considering a radiator with impedance flanges not
equal to zero [4].
The purpose of this paper is to analyse the
influence of an impedance on the electromagnetic
field behaviour of a radiating plane waveguide. In
particular, we investigate the behaviour of the
tangential field components on a waveguide surface
with infinite impedance flanges, taking into account
the specificities of the edges and the radiation pattern.
The paper is organized as follows: in section 2,
we consider the solution to the problem of the
electromagnetic field (EMF) radiation from the open
end of a parallel-plate waveguide with infinite
impedance flanges; numerical results are analyzed in
Section 3, and section 4 is devoted to the conclusion.
II. RADIATION OF A PARALLEL-PLATE
WAVEGUIDE WITH INFINITE IMPEDANCE
FLANGES
2.1. Statement of the problem
First, we consider the solution to the problem of
EMF radiation from the open end of a parallel-plate
waveguide with infinite impedance flanges in the
following setting (Figure 1). Let a parallel-plate
waveguide be excited by a wave characterized by
ii
H,E
, with components,
RESEARCH ARTICLE OPEN ACCESS
2. J François D. Essiben et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 2, ( Part -2) February 2015, pp.104-110
www.ijera.com 105 | P a g e
iky
0
i
z eHH
, iky
0
i
x eWHE
, 0y , (1)
where 120W is the characteristic resistance of
free space and oH is the amplitude of the incident
wave. On the infinite flanges
]0,(x;0y and ),a[ , the boundary im-
pedance conditions of Shukin-Leontovich are ful-
filled:
)Hn(nZEn
, (2)
zx ZHE ,
where yin
is the unit normal to the 0y plane,
and E
and H
are the electric and magnetic fields,
respectively. Z is the surface impedance, so that
0Z specifies a perfect conductor.
Figure 1. The open end of a parallel-plate wave-
guide with infinite impedance flanges.
It is necessary to find the EMF in both regions:
inside the waveguide ( 0y and ax0 , region 2)
and the upper half-space ( 0y , region 1).
The required EMF should satisfy Maxwell’s eq-
uations applied to radiation and the boundary condi-
tions on the flanges, as well as the conditions relevant
to the infinite character of tangential components in
the opening. We consider this problem two-
dimensionally.
2.2. Solution of the problem
For the solution of the proposed problem, we use
the Lorentz lemma in integral form for regions 1V
and 2V as in [4-6], and we choose a thread in-phase
with the magnetic current parallel to the z - axis:
0j .ex.e
and )q,p(Jij m
0z
.ex.m
,
where q,p is a two-dimensional delta-function,
p is the point of observation, q is the point of inte-
gration and, m
0J is the current amplitude.
As a result, the integral correlation for each re-
gion becomes:
xdx,xHxExH m
1z1x1z , (3)
a
0
m
2z2x02z xdx,xHxEH2xH (4)
where x,xH m
z1
and x,xH m
2z
are the subsidiary
magnetic fields in regions 1V and 2V , respectively
(defined below), and a is the dimension of the open
end of the waveguide.
2.3. Integral equations relative to xE .
Correlations (3) and (4) compose a system of
integral equations on the 0y plane. Taking into
account the equality of the tangential field
components, z2z1z HHH ,and x2x1x EEE
in the opening a,0x,0y , and the boundary
condition of equation (2) zx ZHE on the parts of
the flanges with finite impedance ( ])0,L[x(
and ])L,a[x( ), we can obtain a system of
integral equations relative to the unknown tangential
component of the electric field )x(Ex on the 0y
plane:
]L,a[xxdx,xHxE)x(ZxE
]a,[xHxdx,xHxE
xd)]'x,x(H)'x,x(H)[x(Exdx,xHxE
],L[xxdx,xHxE)x(ZxE
L
L
m
zxx
L
a
m
zx
m
z
a
m
zx
L
m
zx
L
L
m
zxx
0
02
00
1
01
2
0
1
0
1
1
(5)
where the subsidiary magnetic fields,
)kR(HW2kJx,xH )2(
0
m
0
m
z1
and
xcosxcoskWakx,xH nn
0n
nn
m
2z
,
are solutions of the non-uniform Helmholtz equation
for the complex amplitudes of the vector potential in
regions 1V and 2V , respectively. This equation can
be solved using the standard method of separation of
variables [7]. Here, 2k is the wave number,
is the wavelength, 22
)'yy()'xx(R is
3. J François D. Essiben et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 2, ( Part -2) February 2015, pp.104-110
www.ijera.com 106 | P a g e
the distance from the point of observation to the point
of integration, 2
0H is the zeroth-order Hankel func-
tion of the second kind,
22
nn kk is the
propagation constant of the wave
...2,1,0n;
a
n
n
, and
0.n2
,0n1
n is the
dielectric permittivity of layer n .
2.4. Effect of the waveguide edges
At the points 0x and ax , the sidewalls of
the waveguide 2V and the flanges converge at right
angles to form edges. Because of the presence of
these edges with zero curvature (see Figure 1), the
surface density of the electric charge becomes locally
infinite. As a result, the vector E
at these points
must be given special consideration [8]:
3/1
xE
,
where is the distance from an edge. In order to
properly take this edge into account in the solution,
we formulate the required value on the interval a,0
as follows:
x'xa
)'x(X
W
)'x(Ex
,
where 3/1 , and the new unknown value xX
is not specified. Equation (5) can then be rewritten as
follows:
].L,a[xxdx,xHxE)x(Z
xdx,xH
x'xa
)'x(X
)x(Zxdx,xHxE)x(ZxE
]a,[xHxdx,xHxE
xd)]'x,x(H)'x,x(H[
x'xa
)'x(X
xdx,xHxE
],L[xxdx,xHxE)x(Z
xdx,xHxE)x(Zxdx,xHxE)x(ZxE
L
a
m
zx
a
m
z
L
m
zxx
L
a
m
zx
m
z
a
m
z
L
m
zx
L
a
m
zx
a
m
zx
L
m
zxx
0
02
00
1
0
1
0
1
01
2
0
1
0
1
1
0
1
0
1
(6)
In the case of ideal conducting flanges
( 0)x(Z , which makes 0Ex on the flanges),
equation (6) turns into a single integral equation:
]a,[x,Hxd)]'x,x(H)'x,x(H[
x'xa
)'x(X m
z
a
m
z 02 02
0
1
.
(7)
The solution of equations (6) or equation (7) is
conveniently solved with the use of the Krylov-
Bogolyubov method [9], which is a piece-wise conti-
nuous approximation to the required value. In this
case, the integral equations (6) transform into a sys-
tem of linear algebraic equations (SLAE):
M,2,1n,H2CX 0m,n
M
1m
m
, (8)
where
xd)]'x,x(H)'x,x(H[
x'xa
1
C n
m
2z
x
x
n
m
1zm,n
m
m
,
x5.0 , )xx(x n1n ,
and )M,2,1n(xn are the lattice points.
II. Results and discussion
Figure 2a shows the results of the solution to the
integral equation (7) for )x(X (dashed line) and
xaxxXxEx (solid line) for a wave-
guide antenna with dimensions, 4.0a , with ideal
conducting flanges, and with the number of lattice
points 60M ( 01.0x ). Analogous results are
presented in Figure 2b for a waveguide with an open-
ing dimension of 8.0a . The discretization step,
x , in both cases is the same as in Figure 2a. Re-
search shows that the required precision in solving
the integral equation is reached with a number of
points across the opening equal to 8 or more.
Figure 3 shows the modulus of the reflection
coefficient (solid line) inside the waveguide, the ar-
gument of this coefficient (dotted curve) and the
modulus of the complete field inside (dashed curve),
which consists of the decaying fields and the reflect-
ed fields. Numerical analysis of the curves shows that
the reflection coefficient is equal to 0.6 and its argu-
ment represents a travelling wave inside the wave-
guide in the form of a saw-tooth curve. The complete
field represents a travelling wave in sinusoidal form.
4. J François D. Essiben et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 2, ( Part -2) February 2015, pp.104-110
www.ijera.com 107 | P a g e
Figure 2. Solution of the integral equation for a
waveguide antenna weith ideal conducting flanges.
The dimension of the open end of the antenna is
(a) 40.a and (b) 80.a . The width 40.L .
Figure 3. Modulus of the reflection coefficient (sol-
id curve), the argument of this coefficient (dotted
curve) and the modulus of the complete field
(dashed curve) inside the waveguide for the ra-
diated plane waveguide. Parameters used are
40.a and 40.L .
Figure 4. Behavior of vectors E
(solid red curve)
and H
(dashed blue curve) on the open end of
the waveguide (a) in the absence of impedance
flanges, 0Z , and (b-c) in the presence of the
flanges (b) iZ 10 , and (c) iZ 10 . Parameters
used are 40.a and 40.L in all cases.
Figures 4(a-c) show the behaviour of vectors E
and H
on the open end of the waveguide in the ab-
sence of impedance flanges (Figure 4a), and in the
presence of the flanges (Figures 4b and c). The para-
meters used are 4.0a and 4.0L in all cases.
As shown, vector E
in all cases has the form of a
parabola over the open end of the waveguide. This
form is inverted for the vector H
in all cases. In the
5. J François D. Essiben et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 2, ( Part -2) February 2015, pp.104-110
www.ijera.com 108 | P a g e
presence of impedance flanges, we note a large inten-
sity of the electric field vector on the flanges for the
case when i10Z , while for the case with
i10Z , the field exponentially decreases away
from the waveguide opening. Furthermore, the level
of the electric field in the open end and on the flanges
is higher for i10Z . Numerical calculations show
that these vectors are calculated with an error margin
not higher than 5 %.
Figure 5. Solution of the integral equation giving
the real and imaginary parts of )x(Ex for (a)
iZ 10 , (b) iZ 10 , and (c) WZ 1 , respec-
tively.
Let us consider the behavior of the tangential
vector components of the field on the 0y surface,
for a waveguide with impedance flanges. Figure 5a
presents the variation of the tangential component of
vector E
)x(Ex for an antenna with capacitive
impedance, i10Z , over the regions 0,L and
aL,a 4.0La of the flanges (the imped-
ance is normalized to 120W ). Corresponding
variations are presented in Figures 5b and 5c, for
inductive i10Z and resistive 1Z impedance
cases, respectively, for the same dimensions as in
Figure 5a ( ZRe , dashed line and ZIm , solid
line). As we can see, the presence of an inductive
impedance leads to the appearance of an electric field
anomaly at the edges of the waveguide antenna on
the sides of the impedance flanges. In addition, the
intensity of the electric field vector located on differ-
ent sides of the waveguide edges has opposite phases.
The presence of this specific feature at the edges of
the waveguide at 0x and ax can be taken into
account by introducing the required functional form
in the following way:
La,axaxx
a,0xxax
0,Lxxax
)x(X)x(Ex
, (9)
where )x(X is a new unknown function without any
specification, and and define the impedance of
the flanges with dimension L .
In this case, the system of integral equations (6),
in accordance with the Krylov-Bogolyubov method,
becomes a SLAE relative to )x(XX nn :
1201
1
2
0110
1
1
1
1
10
12
10
12
12
12
MMnUXfX
MMnHTX
MnUXfX
M
m
m,nmnn
M
m
m,nm
M
m
m,nmnn
, (10)
)x(ZZ nn ; 1M , M , 2M are the numbers of lat-
tice points in the regions 0,L , a,0 , 2La,a ,
respectively; 101 MMM ; 10112 MMM ;
nn
1
n xaxf ;
axxf nn
2
n ;
]M,1M[mD
]M,1M[mG
]M,1[mD
ZU
1201
2
m,n
011m,n
1
1
m,n
nm,n ;
],M,1M[mD
]M,1M[mC
]M,1[mD
T
1201
2
m,n
011m,n
1
1
m,n
m,n
6. J François D. Essiben et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 2, ( Part -2) February 2015, pp.104-110
www.ijera.com 109 | P a g e
and
0,Lxxd
x'xa
)'x,x(H
D n
x
x
n
m
1z1
m,n
m
m
La,axxd
xax
)'x,x(H
D n
x
x
n
m
1z2
m,n
m
m
;
a,0x,xd
x'xa
)'x,x(H
G n
x
x
n
m
1z
m,n
m
m
;
a,0x,xd
x'xa
)'x,x(H)'x,x(H
C n
x
x
n
m
2zn
m
1z
m,n
m
m
Numerical research shows that the smoothest
variation of the required function )x(X is obtained
with the following functional forms of the values of
and :
5,5
Q17.033.0 and 3,4
Q44.021.0 ,
where
Z1
Z
Q
.
As an example, in Figures 6(a-c), we present the
variation of )x(X (dashed line) and the tangential
component of vector E
)x(Ex (solid line) of an
antenna with 4.0a , 4.0LL , and with the
impedance flanges of i1Z (Figure 6a), i10Z
(Figure 6b) and iZ 100 (Figure 6c), respective-
ly. Research shows that with 10ZIm , the ano-
maly (seen in )x(X ) at edge of the impedance
flange is higher than in the waveguide opening. In
the reverse case, it is vice versa. Thus, taking into
account the anomaly of the electric field )x(Ex at
the edges allows us to reduce the solution of the
boundary problem to the search for a gradually
changing function )x(X and consequently, to a sig-
nificant reduction in equation (10) of the order of the
solved SLAE.
The radiation patterns of the single waveguide
antenna are shown in Figure 7 for the capacitive
(solid line), inductive (dashed line), and the ideal
conducting (dotted line) flanges. The impact on the
radiation pattern caused by including impedance re-
gions on the flanges ( 4.0a , 4.0L , 0Z ,
i10Z , and i10Z ), is seen as the difference
between the solid and dashed lines. As we can see,
the capacitive impedance significantly distorts the
wave by increasing the directivity of the antenna but,
the presence of inductive impedance leads to signifi-
cant distortion of the radiation pattern and to a sig-
nificant growth of lateral lobes along the impedance
structure, as well as the deviation of the main lobe,
which is due to the appearance of travelling surface
waves along the structure.
Figure 6. Solution of the integral equation, giving
)x(Ex (solid red curve) and )x(X (dashed blue
curve) for (a) iZ 1 , (b) iZ 10 , and (c)
iZ 100 .
7. J François D. Essiben et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 2, ( Part -2) February 2015, pp.104-110
www.ijera.com 110 | P a g e
Figure 7. Radiation patterns of a single waveguide
antenna for ideal conducting ( 0Z , dotted line),
capacitive ( iZ 10 , solid line), and inductive
( iZ 10 , dashed line) flanges, respectively. The
impact of the impedance part of the flanges on the
radiation patterns is demonstrated with the solid
and dashed lines. Parameters used are 40.a ,
40.L .
III. Conclusion
In summary, we have studied the radiation of a
parallel-plate waveguide antenna. We have calculated
a strict solution to the problem of analysis of the elec-
tromagnetic field behaviour of a single antenna in the
shape of an open end of a parallel-plate waveguide
with an infinite flat impedance flanges. We have
shown that to obtain a higher precision when solving
the integral equation we need to use a large number
of points across the opening of the waveguide, and
also to take into account the particular features of the
waveguide edges.
The electromagnetic field behaviour was investi-
gated by using the impedance approach and the Kry-
lov-Bogolyubov method, which is an iterative ap-
proximation to the required value. The choice of this
method is explained by the fact that it is the most
straightforward method and it allows us to obtain in
analytical form the matrix of coefficients of the sys-
tem of linear algebraic equations, thereby reducing
the computational time.
Finally, we have also shown that a capacitive
impedance distorts the wave by increasing the direc-
tivity of the antenna while, the inductive impedance
leads to significant distortion of the radiation pattern
and to a significant growth of lobes along the imped-
ance structure. We also note that the study of the im-
pedance influence on the electromagnetic field be-
haviour of a parallel-plate waveguide antenna is nec-
essary for solving the problem of coupling between
apertures antennas located on a common impedance
surface.
References
[1] M.Yu. Zvezdina, Influence of impedance
properties located on a mobile construction
on antennas parameters, Radio Electronics,
(3), 2004, 25-29.
[2] Yu.V. Pimenov, V.I. Volman, and A.D. Mu-
ravtsov, Technical Electrodynamics, (Mos-
cow: Radio and Communication Press,
2002).
[3] B.A. Michoustin, Radiation from the open
end of waveguide cylinder with infinite
flanges, Transactions of Higher Education
Institutions, Radio Physics, Gorky (Russia),
8(6), 1965, 1178-1186.
[4] Y.S. Joe, J.-F. D. Essiben, and E.M. Coo-
ney, Radiation Characteristics of Waveguide
Antennas Located on the Same Impedance
Plane, Journal of Physics D.: Applied Phys-
ics, 41(12), 2008, (125503) 1-11.
[5] J.-F. D. Essiben, E. R. Hedin, and Y. S. Joe,
Radiation Characteristics of Antennas on the
Reactive Impedance Surface of a Circular
Cylinder Providing Reduced Coupling,
Journal of Electromagnetic Analysis and
Applications, 2(4), 2010, 195-204.
[6] J.-F. D. Essiben, E. R. Hedin, Y.D. Kim, and
Y.S. Joe, Electromagnetic Compatibility of
Aperture Antennas Using Electromagnetic
Band Gap Structure, IET Microwaves, An-
tennas and Propagation, doi: 10.1049/iet-
map.2012.0100, 6(9), 2012, 982-989.
[7] T. Cwik, Coupling into and scattering from
cylindrical structures covered periodically
with metallic patches, IEEE Transactions on
Antennas and Propagation, 38(2), 1990,
220-226.
[8] G.F. Zargano, L.V. Ptyalin, V.S. Mik-
halevskiy, Y.M. Sinelnikov, G.P. Sin-
yavskiy, and I.M. Chekrygin, Waveguides
of Complicated Cuts, (Moscow: Radio and
Communication Press, 1986).
[9] O.N. Tereshin, V.M. Sedov, and A.F. Chap-
lin, Synthesis of Antennas on Decelerating
Structures, (Moscow: Radio and Communi-
cation Press, 1980).