scholarly journals The Investigation of Coupling between Matching Circuit and Input Resonators of Channels in a Microstrip Diplexer

2020 ◽  
pp. 871-881
Author(s):  
Aleksey O. Afonin ◽  
Andrey A. Leksikov ◽  
Alexander A. Leksikov ◽  
Ilya V. Govorun ◽  
Alexey M. Serzhantov ◽  
...  
Keyword(s):  
Computer Program ◽  
Microstrip Line ◽  
Coupling Coefficients ◽  
Fractional Bandwidth ◽  
Static Approximation ◽  
One Dimensional ◽  
Quasi Static Approximation ◽  
A Value ◽  
Mathematical Expressions ◽  
The Common

This paper deals with investigation of the coupling coefficients between the matching circuit and the input resonators of channels in a microstrip diplexer. Diplexer channels are two-section filters, and matching circuit is regular non-resonant segment of a microstrip line placed between input resonators of channels. The common port is connected to outer end of the segment and its second end is opened. Research was carried out theoretically using a computer program developed on the basis of mathematical expressions obtained by means of one-dimensional models and quasi-static approximation. The results show that a value of coupling is quite large and the use of the matching circuit in a form of a non-resonant segment of a microstrip line allows to design diplexers with wide fractional bandwidth of the channels

scholarly journals Analytical expressions for electrodynamic parameters of the shielded microstrip line

2021 ◽  
Vol 9 (4) ◽  
pp. 68-76
Author(s):  
A. N. Kovalenko ◽  
A. D. Yarlykov
Keyword(s):  
Mathematical Model ◽  
Power Series ◽  
Projection Method ◽  
Microstrip Line ◽  
Wave Resistance ◽  
Strip Conductor ◽  
Static Approximation ◽  
Quasi Static Approximation ◽  
Wide Range ◽  
Analytical Expressions

On the basis of an electrodynamic model of a screened microstrip line, built on the basis of the projection method using the Chebyshev basis, which explicitly takes into account the edge features of the field, a mathematical model of a microstrip line with a strip conductor was developed. The line width does not exceed the height of the substrate. In this case, the current density on the strip conductor is approximated by only one basis function. Analytical expressions are presented in the form of a sum of slowly and rapidly converging series to determine the main electrodynamic parameters of the line – wave resistance and deceleration coefficient. Due to logarithmic features, slowly converging series are summed up and transformed into rapidly converging power series. In addition, limit expressions in the form of improper integrals are given for the main electrodynamic parameters of an open microstrip line in the quasi-static approximation. Due to the logarithmic features, these integrals are also converted to rapidly converging power series. As a result, simple approximate formulas were obtained. They allow calculating the deceleration coefficient and wave impedance of the line with an error not exceeding 1%, when the width of the strip conductor is less than twice the thickness of the substrate. The results of calculating the electrodynamic parameters obtained on the basis of the developed mathematical model and on the basis of the projection method with an accuracy of up to 5 significant digits are presented. These results make it possible to establish the limits of applicability of the quasi-static approximation and to determine the error in calculating the deceleration coefficient and wave resistance using the obtained analytical expressions. The error does not exceed 0.1%, if the width of the strip conductor is less than twice the thickness of the substrate in a wide range of changes in the substrate dielectric constant and frequency.

Certain Problems with the Application of Stochastic Diffusion Processes for the Description of Chemical Engineering Phenomena. Stochastic Model of Non-Isothermal Flow Chemical Reactor

1996 ◽  
Vol 61 (2) ◽  
pp. 242-258 ◽  
Author(s):  
Vladimír Kudrna ◽  
Libor Vejmola ◽  
Pavel Hasal
Keyword(s):  
Stochastic Model ◽  
Chemical Engineering ◽  
Diffusion Processes ◽  
Dispersion Model ◽  
Chemical Reactor ◽  
Segregation Index ◽  
One Dimensional ◽  
A Value ◽  
Isothermal Case ◽  
Flow Through

Recently developed stochastic model of a one-dimensional flow-through chemical reactor is extended in this paper also to the non-isothermal case. The model enables the evaluation of concentration and temperature profiles along the reactor. The results are compared with the commonly used one-dimensional dispersion model with Danckwerts' boundary conditions. The stochastic model also enables to evaluate a value of the segregation index.

Numerical investigation on a melt-blowing die with internal stabilizers

2019 ◽  
pp. 152808371986693 ◽  
Author(s):  
Changchun Ji ◽  
Yudong Wang ◽  
Yafeng Sun
Keyword(s):  
Average Velocity ◽  
Fiber Diameter ◽  
Measurement Data ◽  
Melt Blowing ◽  
One Dimensional ◽  
Temperature Decay ◽  
Slot Die ◽  
The Common ◽  
The One ◽  
Peak Value

In order to decrease the fiber diameter and reduce the energy consumption in the melt-blowing process, a new slot die with internal stabilizers was designed. Using computational fluid dynamics technology, the new slot die was investigated. In the numerical simulation, the calculation data were validated with the laboratory measurement data. This work shows that the new slot die could increase the average velocity on the centerline of the air-flow field by 6.9%, compared with the common slot die. Simultaneously, the new slot die could decrease the back-flow velocity and the rate of temperature decay in the region close to the die head. The new slot die could reduce the peak value of the turbulent kinetic energy and make the fiber movements more gradual. With the one-dimensional drawing model, it proves that the new slot die has more edge on the decrease of fiber diameter than the common slot die.

scholarly journals Level of carbon dioxide diffuse degassing from the ground of Vesuvio: comparison between extensive surveys and inferences on the gas source

2013 ◽  
Vol 56 (4) ◽  
Author(s):  
Domenico Granieri ◽  
Maria Luisa Carapezza ◽  
Rosario Avino ◽  
Stefano Caliro ◽  
Carlo Cardellini ◽  
...  
Keyword(s):  
Emission Pattern ◽  
Diffuse Degassing ◽  
Summit Area ◽  
Gas Source ◽  
A Value ◽  
Volcanic Conduit ◽  
The Common ◽  
Soil Flux ◽  
Different Sources ◽  
Tectonic Line

<p>An extensive campaign of diffuse CO<span><sub>2</sub></span> soil flux was carried out at the cone of Vesuvio in October 2006 with two main objectives: 1) to provide an estimation of CO<span><sub>2</sub></span> diffusely discharged through the soils in the summit area and 2) to evidence those sectors of the volcano where structural and morphological conditions could favour the gas output. The survey consisted of 502 measurements of soil CO<span><sub>2</sub></span> flux homogenously distributed over an area of about 1.8 km<span><sup>2</sup></span>. Results of this survey were compared with those obtained during a similar campaign carried out by Frondini et al. in 2000, from which we have taken and reinterpreted a subset of data belonging to the common investigated area. Graphical statistical analysis showed three overlapping populations in both surveys, evidencing the contribution of three different sources feeding the soil CO<span><sub>2</sub></span> degassing process. The overall CO<span><sub>2</sub></span> emission pattern of 2006 is coherent with that observed in 2000 and suggests that a value between 120 and 140 t/day of CO<span><sub>2</sub></span> is representative of the total CO<span><sub>2</sub></span> discharged by diffuse degassing from the summit area of Vesuvio. The preferential exhaling area lies in the inner crater, whose contribution resulted in 45.3% of the total CO<span><sub>2</sub></span> emission in 2006 (with 62.8 t/day) and in 57.4% (with 70.3 t/day) in 2000, although its extension is only 13% of the investigated area. This highly emissive area correlated closely with the structural discontinuities of Vesuvio cone, mainly suggesting that the NW-SE trending tectonic line is actually an active fault leaking deep gas to the bottom of the crater. The drainage action of the fault could be enhanced by the “aspiration” effect of the volcanic conduit.</p>

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