Complex directional antenna consists of separate near-omnidirectional antennas (radiating elements) positioned in the space and driven by high-frequency …
Yury Vladimirovich Kosyakin, Senior Scientist of Research Institute (Kaluga, Russia), Head of the Branch of the Moscow State Industrial University in Zhukov (Kaluga Region), Candidate of Science in technics.
Development and research of microwave methods for controlling absorbent materials
The aim of the thesis is to develop and research new microwave methods and devices for nondestructive control over linear resistance in a high-resistance microwire and a nonmetallic electrically conductive thread and to measure the magnetic conductivity of thin and narrow tapes made of amorphous metal alloy (AMA).
The development of such control systems is used to solve the problem at hand — creating all kinds of measurement devices making it possible to carry out constant and nondestructive control over the linear resistance of a high-resistance microwire and a high-resistance electrically conductive thread with lacquer coating and also to measure the magnetic conductivity of thin tapes made of AMA with a large limit of their values within the range of high frequencies and microwaves having the effective resolution of linear resistance and magnetic conductivity. It is important to discover and research such measurement structures that would make it possible to implement the broadbandness of measurement devices for the above materials.
The thesis dwells on the development of new methods for controlling the linear resistance and magnetic conductivity of various materials, the development and research of new structures for measurement systems and their electrodynamic estimation. It allowed several structures to be estimated with the help of a uniform approach.
In particular, the following items were offered and considered for the first time:
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A below cutoff circular septate waveguide and also a system of two connected coaxial resonators with loaded capacitance having an axial bore connected with the help of a piece of a below cutoff circular waveguide for measuring the linear resistance of high-resistance wires.
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A helical decelerating system in the form of a metal rod with a deep helical groove in the screen and a contrary-direction double helical decelerating system with a central conductor for measuring the magnetic conductivity of thin tapes made of amorphous metal alloys for high frequencies and microwaves.
The practical value of the created measurement devices comes down to the following:
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Devices making it possible to control the linear resistance of a high-resistance wire in without a contact during its continuous motion within a wide range of frequencies in a non-contact way have been created.
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Now it is possible to create devices for measuring the magnetic conductivity of thin tapes made of AMA for high frequencies and microwaves.
The following statements are defended in the thesis:
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The following dependences are used for non-contact continuous control over the linear resistance of a high-resistant isolated wire for microwaves:
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The dependence of the attenuation coefficient in a below cutoff septate waveguide on the linear resistance of a wire located along the axis of the septate waveguide.
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The dependence of the bifurcation value of the resonance peak in the sensor based on two connected coaxial resonators with loaded capacitance on the linear resistance of a wire located in the center of the axial bore of this sensor.
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The values of the slowdown coefficient and the attenuation coefficient in a helical slowdown system in the form of a rod with a deep helical groove with a thin tape out of amorphous metal alloy located in it in the screen make it possible to determine the value of the complex magnetic conductivity of this tape.
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A change in the slowdown coefficient in connected helices in case of their in-phase excitation depending on the magnetic conductivity of thin tapes made of isomorphic metal alloy located between helices parallel to their longitudinal axis makes it possible to determine the value of the magnetic conductivity of these tapes.
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