Convergence of Characteristics of a Microstrip Line with Rectangular and Rounded Conductors of Different Widths

In this paper a microstrip line (MSL) with rectangular and rounded conductor shapes is investigated. For each conductor shape, simulation in the TALGAT system is performed and values of the per-unit-length capacitance (C), the per-unit-length capacitance in vacuum (C
0
), the per-unit-length delay (τ) and the impedance (Z) at different values of segment length (S) (with uniform auto-segmentation of all conductor and dielectric boundaries) and the conductor width (w) are calculated. Convergence results for the two conductor shapes are presented. It is found that with decreasing S the maximum changes decrease from 1.6% to 0.3% on average for ΔC, ΔC
0
and ΔZ and from 0.7% to 0.06% for Δτ. Increasing w from 0.2 mm to 0.4 mm improves the convergence for all characteristics of the MSL.