Silicon-based terahertz (THz) integrated circuits (ICs) have made rapid progress over the past decade. The demonstrated basic component performance, as well as the maturity of design tools and methodologies, have made it possible to build high-complexity THz integrated systems. Such implementations are undoubtedly highly attractive due to their low cost and high integration capability; however, their unique characteristics, both advantageous and disadvantageous, also call for research investigations into unconventional systematic architectures and novel THz applications. In this paper, we review Manuscript