Strong coupling (crosstalk) between printed microstrip transmission lands on printed circuit boards

In this paper, strong coupling (crosstalk) between microstrip transmission lands on printed circuit board is investigated from an electromagnetic compatibility (EMC) point of view. Near-end and Far-end crosstalk expressions between microstrip transmission lines were derived analytically and then validated using ADS Momentum and circuit simulator. For experimental validation, three cases of coupled microstrip transmission lines (3mm, 5mm and 10mm separation) on three separate PCBs were fabricated on Rogers FR4 substrate with the relative permittivity of 4.6 and thickness of 1.6 mm. The near- and far-end crosstalk were measured using in-house Agilent network analyzer. The measured results of near- and far-end crosstalk closely match with the ADS Momentum results. The developed analytical model can be used both for weak and strong coupling computation.