The method of quality factor calculation of irregular transmission line resonator

DOI №______

Abstract

In the approximation of small losses obtained analytical expressions for determining the quality factor resonators based on irregular transmission lines. The study found that the synthesis resonator task is to determine the distribution of this law the total losses in dielectrics and conductors such law and impedance changes along the line, in which the value of merit will be maximum. Resonators are an essential element of selective devices that determine the basic characteristics of telecommunication systems. One of the main parameters of the resonance is known, is the quality factor characterizing selective properties of resonators determines the steepness of the slopes amplitude-frequency characteristics of filter devices built on them. One of the ways to increase selective properties resonators are increasing their quality factor by reducing losses and use of lines of varying the length of characteristic impedance (irregular lines). However, using irregular lines loss is a problem with the definition of quality factor resonators such as the exact solution of the telegraph equation for irregular lines there is only accurate solution for individual cases. In the synthesis resonators for the frequency spectrum (sections resonance frequencies) there is no need to find intermediate characteristics once defined characteristic impedance irregular lines and therefore the problem of determining quality factor is reduced to solving telegraph equations with variable coefficients or to solve nonlinear Riccati equation regarding impedance line. Decisions above equation is possible only in certain special cases, not to evaluate selective resonator properties to the full, particularly with complex resonator impedance changes in the law.

Keywords: Q-factor of the resonator; irregular transmission lines; selective properties; frequency range; electromagnetic field; wave resistance; slope steepness.

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