The paper describes a method for the analysis of the four-port junction (X-junction) between two rectangular waveguides and a circular waveguide. The method is based on the computation by an efficient technique of the...
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The paper describes a method for the analysis of the four-port junction (X-junction) between two rectangular waveguides and a circular waveguide. The method is based on the computation by an efficient technique of the generalized admittance matrix (GAM) of the structure (conveniently divided into sub-blocks) with no restrictions on the geometrical dimensions. a typical analysis with about 100 modes in the overall structures requires 1-4 s per frequency point on a typical medium-power workstation.
Compact high-efficient TE10-TEq0-mode converters based on truncated H-plane angular junctions of single-mode and overmoded rectangular waveguides are designed and investigated. The comparison analysis of converters wi...
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Compact high-efficient TE10-TEq0-mode converters based on truncated H-plane angular junctions of single-mode and overmoded rectangular waveguides are designed and investigated. The comparison analysis of converters without and with an inductive iris in the input port is carried out. Iris-free converters are broader in bandwidth, while iris-matched ones provide a better purity and higher conversion efficiency. It is found that the same configuration can provide a high-efficient conversion to different TEq0 modes in different parts of the frequency operation range. Two interpretations of the conversion physical mechanism are discussed.
A new method for calculating the performance of an iris-loaded planar phased-array antenna of rectangular waveguides is presented. The method is based upon the expansion of the tangential electric aperture field in te...
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A new method for calculating the performance of an iris-loaded planar phased-array antenna of rectangular waveguides is presented. The method is based upon the expansion of the tangential electric aperture field in terms of judiciously chosen functions. Also, the influence of a dielectric sheet in front of an antenna the apertures of which are loaded with inductive irises is investigated. In the experiments, a sheet with a low relative permittivity ( \epsilon_{r} = 2.3 or \epsilon_{r} = 3.5 ) is spaced in front of a space-fed planar antenna of some 850 radiating elements, and the total transmitted power of the antenna is measured as a function of frequency and scan angle. The results indicate, that both in theory and in practice, an excellent match can be achieved with a polythene sheet ( \epsilon_{r} = 2.3 ) or a Perspex sheet ( \epsilon_{r} = 3.5 ).
An exact solution for the complex propagation constant in semiconductor loaded waveguides is obtained by superimposing a finite number of plane waves. The analysis is carried out through the study of the parallel-plat...
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An exact solution for the complex propagation constant in semiconductor loaded waveguides is obtained by superimposing a finite number of plane waves. The analysis is carried out through the study of the parallel-plate waveguide. Numerical results have been obtained by means of a numerical program previously set up. Reciprocal and nonreciprocal behavior of the electromagnetic (EM) structure, depending on the semiconductor parameters, geometrical parameters, and applied magnetic field, is illustrated. A good quantitative agreement between the theory and the experiments in [11] is shown.
The stationary expressions for the scattering coefficients are given for a finite planar waveguide array (FPWA) with dielectric plugs whose dielectric constants and lengths are arbitrary. The scattering coefficients d...
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The stationary expressions for the scattering coefficients are given for a finite planar waveguide array (FPWA) with dielectric plugs whose dielectric constants and lengths are arbitrary. The scattering coefficients defined at the air-dielectric interfaces in the waveguides are expressed in terms of the aperture electric fields only and evaluated from the ratio of two determinants. This method is useful for analyzing the mutual coupling effects in FPWA.
In this paper, we consider a method for null synthesis in the vector sum and difference beam patterns of a monopulse array of rectangular waveguides. The synthesis of nulls is reached due to variation of complex curre...
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It is shown that coaxial waveguides can have losses within a factor of 2.4 of rectangular waveguide. Furthermore, for impedance levels less than approximately 135 ohms, properly dimensioned coaxial guides are less los...
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It is shown that coaxial waveguides can have losses within a factor of 2.4 of rectangular waveguide. Furthermore, for impedance levels less than approximately 135 ohms, properly dimensioned coaxial guides are less lossy than rectangular guides of the same impedance level. The realization of this point is of significance in microwave solid-state circuit design.
A numerical analysis of an infinite phased array of open rectangular waveguides has been made which includes the effects of wall thickness. Two planes of scan, the H and quasi- E planes, have been considered. In these...
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A numerical analysis of an infinite phased array of open rectangular waveguides has been made which includes the effects of wall thickness. Two planes of scan, the H and quasi- E planes, have been considered. In these cases, the general vector problem can be expressed in the form of a scalar one-dimensional Fredholm integral equation of the first kind. The approximate fields obtained numerically from the integral equation are used for the evaluation of the input complex reflection coefficient. A variational expression for the reflection coefficient is developed and used for improving the accuracy. Numerical results for the H and quasi- E plane scans are presented as a function of wall thickness and scan angle. Agreement with experimental results is very good.
rectangular waveguide junctions are widely used in antennas and waveguide devices and, in this connection, the study and optimization of their electrodynamic characteristics is very important for practical application...
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An exact method is developed for the calculation of the electrical performance of the rectangular waveguide T-junction. This method is used to find the equivalent circuit of a rectangular waveguide T-junction in which...
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An exact method is developed for the calculation of the electrical performance of the rectangular waveguide T-junction. This method is used to find the equivalent circuit of a rectangular waveguide T-junction in which both cross-sectional dimensions of the side waveguide are different from the cross-sectional dimensions of the through waveguide. The theoretical calculations for a particular T-junction of this type are verified by experimental measurements. In this method the electrical performance is analyzed by using equivalent-circuit concepts applied to waveguide modes to calculate an admittance matrix relating propagating and cutoff waveguide modes to each other. Then the cutoff modes are terminated in their characteristic impedance, and an equivalent admittance matrix of the junction is found relating only the propagating modes in each waveguide to each other. The anlysis is valid when any number of modes can propogate in the waveguides forming the junction. The Inversion of an infinite matrix is required; however, any desired accuracy can be obtained by considering a matrix of finite but sufficient size or equivalently by considering a sufficient number of cutoff modes.
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