Wave Propagation Mechanisms for Intra-Chip Communications

Fundamental wave propagation mechanisms for intra-chip communications in a multilayered IC chip structure are studied theoretically and numerically. The well-known Green's function representation in terms of branch cuts (continuous spectrum), residues (discrete spectrum), and direct source-receiver radiation is used to clarify important wave processes for typical intra-chip antenna structures. It is found that surface waves may or may not provide the dominant propagation channel contribution, depending on frequency and chip structure. We generalize the concept of multipath to include multiple spectral (e.g., discrete and continuous) wave components, appropriate for the near- and intermediate-field problems of interest for chip-scale propagation. The effect of a guiding layer placed either below or above the silicon substrate is considered. It is found that a guiding layer can provide enhanced single-channel signal transmission via the surface wave channel, and thereby reduce dispersion associated with multi wave component effects.