Hybrid S-parameters for analysis of mixed RF-digital circuits subject to external electromagnetic interference

We extend the port analysis technique to accommodate external plane wave coupling. In other words, we propose a frequency domain method which overcomes the CPU bottleneck of time domain techniques and concurrently yields increased accuracy as compared to MTLT. As part of this formalism we introduce additional hybrid S-parameters to establish a link between the existing board ports and external plane waves. Thus, we can handle both on-board and off-board EMI problems simultaneously. This approach can be easily integrated into circuit solvers such as HSPICE and Advanced Design System (ADS, Agilent Technologies). This is achieved by exporting new hybrid S-parameters. The method allows both time domain simulations via broadband network characterization and harmonic balance simulation of nonlinear RF components.