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This thesis is based on a concept of increasing the inverter circuit frequency by setting the working circuit resonance frequency by tripled frequency of power elements switching. Such a solution enables applying of standard controlling methods and increasing the working frequency of the inverter at the same time. A research for inverter working with resonance frequency of maximum 455 [kHz] was carried out on a practical model. The results of the research were satisfactory and have confirmed prior theoretical calculations and simulations. Source

The subject of the paper is a model of symmetrical transmission stripline provided transverse electromagnetic wave (TEM) with strictly defined value of homogenous electric field generated inside for testing electric, electronic devices from electromagnetic compatibility point of view. Applied two-dimensional stripline calculating model is much more simple than normally used three-dimensional model. Theoretical expressions were used to design the Crawford Cell TEM for verification calculated and measured values electric field density inside the chamber. Source

Gasiorski A.,Czestochowa University of Technology | Posylek Z.,Instytut Telekomunikacji i Kompatybilnosci Elektromagnetycznej
Przeglad Elektrotechniczny

In this paper the identification of the electric component of electromagnetic field in the measurement space of GTEM cell was carried out by using computing method and measurement identification. The method of uniform electric field density recommended in European norms was used to value electric field density in measurement space. The normalized value of the perpendicular component of TEM wave electric field in the GTEM cell test space was calculated from an equation and it relates to cell dimensions and its characteristic impedance. The identification of this normalized perpendicular component of the field in the cell measurement space was carried out by doing measurements. After comparing obtained computing and measuring results it came out that there is a satisfied convergence between these results for frequencies up to 100[MHz]. Source

In this thesis the influence of the air gap and its shape on selected frequency parameters for induction coil with divisible ferrite core composed of two typical U-type cores was researched. On a real object the impedance module and phase of the whole circuit in function of frequency were determined by measuring. The measurements were carried out for ferrite cores without air gaps, with double-sided air gaps, onesided air gaps with bevel cut surface and in shape of one-sided step. The obtained results of measurements led to conclusions referring to usage of proper air gaps for ferrite cores in RF circuits. Source

In this thesis a research of laboratory models of wireless electric energy transmission circuit was carried out. Three structures where examined: coil by coil, coil on coil (in the air and on the same ferrite core) and transformer structure with bipartite ferrite core and changeable thickness of air gaps. Primary coil is supplied with sinusoidal voltage of frequency lower than RF. Characteristic parameters of the coil (with and without ferrite core) were calculated and then changes of coupling coefficient in function of frequency for different coil positions were derived. Transformator's self-induction, mutual induction and winding coupling coefficient were calculated. Obtained computing and measuring results it came out that there is a huge convergence between these results for the analyzed cell. Source

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