Mathematical Apparatus to Analyze Interference-Suppressing Strip Devices With Asymmetric Structure

Abstract

A mathematical apparatus that is used to analyze protective devices based on a meander line (ML) turn. The apparatus takes into account the effect of asymmetry of cross-section on the propagation of pulse signal in a turn The developed mathematical apparatus includes: a model for calculating radiated emissions from a turn with an arbitrary cross-section; an analytical model for calculating the time response at the turn output; models for obtaining conditions that ensure the complete ultrashort pulse (USP) decomposition in multistage devices The proposed apparatus was evaluated on the example of structures with broad-side and side coupling (by the comparison with the results of computer simulation). As a result of comparison of frequency dependences of the maximum electric field strengths obtained using the model and numerically were produced ambiguous results. For the ML turn with broad-side coupling, the dependences were found to be in good agreement qualitatively in the frequency range up to 2.5 GHz. However, they can differ significantly in terms of quantity. More specifically, at some frequencies, there are pronounced maxima of the frequency dependences obtained numerically. For the turn with side coupling, the amplitudes of the maximum field strengths calculated by the model were found to be higher in the entire frequency range (with the exception of several maxima) than those calculated numerically. The constructed directional diagrams of the turn confirm the quantitative discrepancies. Meanwhile, the analysis of the obtained results allows us to claim that the real field strengths will be lower than those calculated by the model, so the model is applicable for preliminary estimates. As a result of evaluation of the analytical model for calculating the time response at the turn output revealed a complete coincidence of the time responses obtained on the basis of the model and numerically. Finally, the models to obtain the conditions for the complete pulse decomposition were evaluated on the example of 3-stage devices. The results demonstrated that the developed models were correct. The case was also considered when the conditions obtained using the models are not met, which leads to an increase in the signal amplitudes at the output of the devices. Thus, the entire presented mathematical apparatus can be used to analyze protective devices based on an ML turn with an asymmetric cross-section.