Monitoring the parameters of printed striplines in the microwave range of electromagnetic waves

The article describes the imperfection of metrological support for measuring the parameters of microwave objects in non-standard guiding systems, including printed striplines, due to the current lack of a universally accepted accurate methods for determining the characteristic wave impedance of printed striplines. A method is proposed to enable experimental monitoring of the entire set of parameters of the printed strip transmission lines, such as characteristic wave impedance, relative effective dielectric permittivity, as well as phase velocity and attenuation coefficient of the propagating electromagnetic waves. The characteristic wave impedance is determined by the S-parameters of the connection of coaxial-to-stripline transitions with a segment of an electrically long line. The wave parameters measured in the coaxial channel are transformed in the area of contact of the coaxial and strip transmission lines, which makes it possible to obtain an analytical estimate of the wave impedance over the entire frequency range of the vector network analyzer or at least within its individual frequency windows. In the proposed method, the phase velocity, attenuation coefficient, and relative effective dielectric constant are determined by the phase-differencing method based on the results of measuring the transmission coefficients of coaxial strip junction connections transformed in the contact areas by sections of electrically long and short printed strip transmission lines. The functional capability of the proposed method for monitoring the parameters of printed striplines has been confirmed by computer-aided modeling, and its effectiveness—by a full-scale experiment. The obtained results can be used by engineers developing integrated microwave technology and specialists in the field of monitoring object parameters in non-standard guide systems.