Estimation of influence of the substrate material of the modal filter with electromagnetic absorber on the difference of the modal delays

The paper presents the results of an estimation of the influence of the substrate material on delays of a modal filter with an electromagnetic absorber. The modal filter was simulated by using electrodynamic and quasistatic approaches in the frequency range from 0 to 10 GHz. The time responses to a trapezoidal pulse of short duration were estimated using N-norms. The minimum output pulse amplitude was 0.125 V for FSD220G material with a conductor length of 1000 mm. The maximum output pulse amplitude was 0.217 V for FR-4 material with a conductor length of 1000 mm. The maximum difference of per-unit-length delays of the propagation modes was 3.577 ns for the FSD220G material.