Build and review time-domain and frequency-domain models for package, board, socket, connector, interposer, and fixture interconnect structures, including insertion loss, return loss, crosstalk, mode conversion, skew, impedance discontinuity, and resonances. Support package-level power distribution network planning and review activities, including target impedance, decoupling strategy, current-density review, DC IR drop, AC droop or noise behavior, plane or cavity resonance, extraction strategy, and measurement correlation.