scholarly journals Analytical Dispersion Equations of a Lossy Coaxial Waveguide in the Microwave and Visible Spectra

2021 ◽  
Vol 21 (2) ◽  
pp. 119-125
Author(s):  
Yong Heui Cho
Keyword(s):  
Coaxial Line ◽  
Coaxial Waveguide ◽  
Electric Conductor ◽  
Dispersion Equations ◽  
Mode Dispersion ◽  
Visible Spectra ◽  
Electrical Conductivities ◽  
Matching Technique ◽  
Complex Propagation ◽  
Coaxial Waveguides

Analytical hybrid-mode dispersion relations of a lossy coaxial waveguide were rigorously analyzed using a mode-matching technique. In order to model a practical coaxial line with inevitable losses, we adopted an all-dielectric coaxial waveguide surrounded by the perfect electric conductor (PEC) boundary. The rigorous dispersion characteristics of the TM<sub>01</sub>, TE<sub>01</sub>, and EH<sub>11</sub> modes were investigated for lossy coaxial waveguides filled with different electrical conductivities. Based on the exact solutions, approximate but accurate dispersion equations were proposed for the TM<sub>0<i>p</i></sub>, TE<sub>0<i>p</i></sub> , EH<sub><i>mp</i></sub>, and HE<sub><i>mp</i></sub> modes in order to estimate and compare the behaviors of complex propagation constants in the microwave and visible spectra.

scholarly journals Calculation of a non-reflective connection in a coaxial line

2021 ◽  
Vol 29 (1) ◽  
pp. 99-104
Author(s):  
V. M. Morozov ◽  
V. I. Magro
Keyword(s):  
Integral Equation ◽  
Reflection Coefficient ◽  
Coaxial Line ◽  
Integral Equation Method ◽  
Coaxial Waveguide ◽  
Equation Method ◽  
System Of Equations ◽  
T Wave ◽  
Significant Difference ◽  
Coaxial Lines

The calculation of the non-reflective connection in the coaxial line is performed by the integral equation method. The connection of coaxial lines with a significant difference in geometric dimensions is considered. A system of equations is obtained that allows calculating the reflection coefficient of the T-wave from such an inhomogeneity. This technique makes it possible to calculate a multistage coaxial waveguide in order to minimize the reflection coefficient from inhomogeneities.

Technique for Measuring the Dielectric Properties of Minerals as a Function of Temperature and Density at Microwave Heating Frequencies

1990 ◽  
Vol 189 ◽  
Author(s):  
Johanna B. Salsman
Keyword(s):  
Dielectric Properties ◽  
Microwave Heating ◽  
Research Effort ◽  
Coaxial Line ◽  
Dielectric Constants ◽  
Dielectric Constant And Loss ◽  
Electrical Conductivities ◽  
Natural Density ◽  
The Common ◽  
Method Of Measurement

ABSTRACTAs part of the research effort on investigating the effects of microwave energy absorption on the chemical and physical properties of minerals and ores, the Bureau of Mines, Tuscaloosa Research Center has developed a technique of measuring the dielectric constant and loss tangent of minerals at the common microwave heating frequencies. The objective was to establish a reliable data base to aid in predicting the effects of microwave heating on minerals.In this phase of microwave research, the Bureau measured the dielectric properties of powdered minerals with medium to high electrical conductivities (a ≥ 0.02 Mho/m) in the frequency range of 300 MHz to 3 GHz using an open-ended coaxial line probe connected to an HP 8753A network analyzer. Since the minerals were prepared as powders, techniques were used to relate the measured dielectric properties of the powdered minerals to the dielectric properties of the mineral at Its theoretical or natural density. Also, these measurements were performed as a function of temperature, from 25° to 325° C.The measured values of the dielectric constants and loss tangents using this method were accurate within ±5 percent. This report describes the method of measurement and discusses the results of the Bureau's investigations into dielectric properties of minerals.

Low-spurious-response coaxial-line BPF with saucer-loaded stepped-impedance resonators designed with mode-matching technique

2004 ◽  
Vol 14 (3) ◽  
pp. 227-235
Author(s):  
Hiromitsu Uchida ◽  
Tetsu Ohwada ◽  
Naofumi Yoneda ◽  
Norio Takeuchi ◽  
Moriyasu Miyazaki ◽  
...  
Keyword(s):  
Coaxial Line ◽  
Mode Matching ◽  
Matching Technique ◽  
Spurious Response ◽  
Mode Matching Technique

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

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