DIFFRACTION OF MICROWAVES BY LONG METAL CYLINDERS

1955 ◽  
Vol 33 (8) ◽  
pp. 407-419 ◽  
Author(s):  
Albert W. Adey
Keyword(s):  
Plane Wave ◽  
Electric Field ◽  
Transmission Line ◽  
Cross Section ◽  
Parallel Plate ◽  
Rectangular Cross Section ◽  
Circular Cylinders ◽  
Wave Conditions ◽  
Rectangular Cylinders ◽  
Good Agreement

A parallel-plate transmission line has been applied to the study of the amplitude and phase of the diffracted electric field near metal cylinders of circular, square, and rectangular cross-section. The transverse dimensions of the cylinders are comparable with the wavelength (3.280 cm.). A travelling dipole probe inserted in the line through a slot in one of the plates permits investigation of the field. Absorbing wedges at the boundary of the line make the plates effectively infinite in extent. Essentially plane wave conditions exist in the region utilized in the measurements. Good agreement is obtained between calculation and experiment for circular cylinders. Measured results are given for square and rectangular cylinders. For one orientation of the rectangles the measured results are compared with approximate calculations.

scholarly journals Plane Wave Coupling to a Transmission Line Above Ground with Terminating Loads

2019 ◽  
Vol 8 (1) ◽  
pp. 82-90
Author(s):  
L. K. Warne ◽  
S. Campione ◽  
R. S. Coats
Keyword(s):  
Plane Wave ◽  
Transmission Line ◽  
Radiation Effects ◽  
Short Circuit ◽  
Open Circuit ◽  
Simple Circuit ◽  
Transmission Line Model ◽  
Wave Coupling ◽  
Full Wave ◽  
Good Agreement

This paper considers plane wave coupling to a transmission line consisting of an aerial wire above a conducting ground. Simple circuit models are constructed for the terminating impedances at the ends of the line including radiation effects. We consider the following load topologies: open circuit, short circuit, and grounded rods. Results from the transmission line model with these loads show good agreement with full-wave simulations.  

In-Plane Vibrations of Thick Circular Rings With T or I Cross Sections

1979 ◽  
Vol 46 (2) ◽  
pp. 470-472
Author(s):  
H. Lecoanet ◽  
J. Piranda
Keyword(s):  
Experimental Data ◽  
Eigenvalue Problem ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Circular Rings ◽  
Theoretical Results ◽  
Good Agreement

This paper deals with the problem of eigenfrequencies and eigenvectors for rings whose cross section may be decomposed in basic rectangular cross sections. The solution is derived from a solution of the in-plane eigenvalue problem for rectangular cross-section thick rings. A good agreement between theoretical results and experimental data is obtained.

RADIATION AND RECEPTION PROPERTIES OF A WIDE SLOT IN A PARALLEL-PLATE TRANSMISSION LINE: I

1959 ◽  
Vol 37 (2) ◽  
pp. 144-159 ◽  
Author(s):  
R. F. Millar
Keyword(s):  
Plane Wave ◽  
Transmission Line ◽  
Free Space ◽  
Parallel Plate ◽  
Dominant Mode ◽  
Reciprocity Theorem ◽  
Polar Diagram ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Lorentz Reciprocity Theorem

A solution is obtained to the problem of radiation from a slot in a parallel-plate transmission line when excited by an E-polarized, dominant mode wave. Expressions are obtained for the reflection and transmission coefficients, and the polar diagram of the radiated field. Explicit calculations are performed when the width of the slot is much greater than the free-space wavelength of the incident radiation.An application of the Lorentz reciprocity theorem yields, without further analysis, the amplitude and phase of the propagated wave which is excited in the line by an incident cylindrical or plane wave.

SCATTERING OF ELECTROMAGNETIC WAVES BY COAXIAL CYLINDERS

1956 ◽  
Vol 34 (5) ◽  
pp. 510-520 ◽  
Author(s):  
Albert W. Adey
Keyword(s):  
Transmission Line ◽  
Electromagnetic Waves ◽  
Parallel Plate ◽  
Near Field ◽  
Experimental Results ◽  
Metal Cylinder ◽  
Scattering System ◽  
Coaxial Cylinders ◽  
Scattered Fields ◽  
Good Agreement

A scattering system comprising two coaxial, dielectric cylinders has been studied theoretically and experimentally. Calculations have been made of the forward and back scattered fields for several combinations of inner and outer radii. It has been found that, by covering a metal cylinder with a coaxial dielectric shield, it is possible to eliminate to some extent the deep near-field shadow. Experimental results obtained at a wavelength of 3.275 cm. using a parallel-plate transmission line are in good agreement with calculations.

RADIATION AND RECEPTION PROPERTIES OF A WIDE SLOT IN A PARALLEL-PLATE TRANSMISSION LINE: II

1959 ◽  
Vol 37 (2) ◽  
pp. 160-169
Author(s):  
R. F. Millar
Keyword(s):  
Plane Wave ◽  
Transmission Line ◽  
Parallel Plate ◽  
Slot Width ◽  
Reflection And Transmission Coefficients ◽  
Parallel Plates ◽  
Polar Diagram ◽  
Reflection And Transmission ◽  
Transmission Coefficients

The study initiated in Part I is continued, with consideration being given to the case in which only a TEM wave is propagated in the parallel-plate region. The reflection and transmission coefficients, and the polar diagram of the radiated field are determined.The amplitude and phase of the propagated wave excited in the line by an incident cylindrical or plane wave are determined by reciprocity arguments.Curves are presented to illustrate the dependence of the field on the slot width and the distance between the parallel plates, for the two field types considered here and in the previous paper.

Modal Curves of Pre-Twisted Beams of Rectangular Cross-Section

1969 ◽  
Vol 11 (1) ◽  
pp. 1-13 ◽  
Author(s):  
B. Dawson ◽  
W. Carnegie
Keyword(s):  
Cross Section ◽  
Rectangular Cross Section ◽  
Twist Angle ◽  
Ritz Method ◽  
Transformation Method ◽  
Mode Shapes ◽  
Modes Of Vibration ◽  
Vibrational Characteristics ◽  
Theoretical Results ◽  
Good Agreement

An important aspect of the theoretical study of the vibrational characteristics of turbine and compressor blading is the prediction of the modal curves from which the stresses along the length of the blading can be determined. The accurate prediction of the modal curves allowing for such factors as pre-twist, camber, size of cross-section, centrifugal tensile effects, aerodynamic effects, etc., is still not possible. However, a better understanding of the effects of some of these parameters can be obtained by a study of the modal curves of relatively simple idealized models. In this work the theoretical mode shapes of vibration of pre-twisted rectangular cross-section beams for various width to depth ratios and pre-twist angle in the range 0-90° are examined. The theoretical results are obtained by the transformation method given by Carnegie, Dawson and Thomas (1)† and the accuracy of these results is verified by comparison with results obtained by Dawson (2) using the Ritz method. The theoretical results are compared to modal curves determined experimentally and good agreement is shown between them. A physical explanation of the effects of the pre-twist angle upon the modal curves is given for the first three modes of vibration.

USING OF BEZIER FORMULATION FOR CALCULATION OF STREAMLINE, STRAIN DISTRIBUTION AND EXTRUSION LOAD IN RECTANGULAR CROSS SECTION OF ECAE PROCESS

2013 ◽  
Vol 10 (03) ◽  
pp. 1350005 ◽  
Author(s):  
K. NAROOEI ◽  
A. KARIMI TAHERI
Keyword(s):  
Cross Section ◽  
Strain Field ◽  
Deformation Zone ◽  
Equal Channel Angular Extrusion ◽  
Rectangular Cross Section ◽  
Extrusion Pressure ◽  
Complex Geometries ◽  
General Process ◽  
Volume Constancy ◽  
Good Agreement

In this research, a general solution of volume constancy differential equation is presented based on the equation of deformation field for a general process. As the Bezier method is suitable for construction of complex geometries, the solution is used in conjunction with the Bezier method to analyze the equal channel angular extrusion (ECAE) process of rectangular cross section. Thus, a generalized kinematically admissible velocity field is derived from the equation of deformation zone such that the compatibility of the surface representing the deformation zone is fulfilled. The effects of die angle, friction between the billet and die wall, and the angle of outer curved corner, on extrusion pressure are all considered in the analysis. It is found that extrusion pressure decreases with increasing both the die angle and the outer curved corner angle and with decreasing the friction coefficient. Also, the effect of die curvature on inhemogenity of strain is assessed. It is exhibited that increasing the angle of outer curved corner decreases the extrusion pressure and increases the inhomogeniety of strain field of deformation zone. A good agreement is found between the predicted and experimental results pertaining to two dies of different outer curved corner.

Sign in / Sign up

Export Citation Format

Share Document