Modeling of superconducting integrated structures in the frequency range was carried out 300...750 GHz by two methods: 1) using ABCD matrices associated with each element of the circuit; 2) using the Ansys HFSS program. The surface impedance values of superconducting films are calculated numerically using expressions from the Matthies–Bardeen theory. It was found that for samples with microstrip line widths less than a quarter of the wavelength, both models are in qualitative agreement with each other and with experimental data. Shown that with an increase in the width of the lines and the geometric dimensions of other structural elements, transverse modes arise, as well as curvature of the wave front propagating along the lines waves, which causes differences between the semi-analytical and numerical calculations, which coincide with the experiment for all samples.