Simulating a Microstrip Line with an Additional Conductor on Top under Different Boundary Conditions at its Ends

The paper presents the study of the time response of a microstrip line (MSL) with an additional conductor on top with different boundary conditions at its ends. Quasi-static simulation is performed in the TALGAT system. More specifically, the line cross-section is constructed, and the time responses to the ultra-short pulse (USP) at different boundary conditions at the conductor ends are calculated. It is shown that the investigated line can be used as a modal filter (MF) with certain parameters under the following boundary conditions: a short circuit (SC), a 50 Ohm, and their combination. With one set of cross-sectional parameters, the pulse amplitudes are equal only under the SC boundary condition and are 1.22 V (two-fold attenuation). The time responses with equalised amplitudes, when the line is matched and at 50-Ohm SC, are also shown separately. These are obtained for specific values of the line parameters. The results can be used to design stable transmission lines and protection devices based on them.