This paper presents an on-chip, interconnect-aware methodology for high-speed analog and mixed signal (AMS) design which enables early incorporation of on-chip transmission line (T-line) components into AMS design flow. The proposed solution is based on a set of parameterized T-line structures, which include single and two coupled microstrip lines with optional side shielding, accompanied by compact true transient models. The models account for frequency dependent skin and proximity effects, while maintaining passivity requirements due to their pure RLC nature. The signal bandwidth supported by the models covers a range from DC to 100 GHz. The models are currently verified in terms of S-parameter data against hardware (up to 40 GHz) and against EM solver (up to 100 GHz). This methodology has already been used for several designs implemented in SiGe (Silicon-Germanium) BiCMOS technology.