The digital twin (DT) is a core technology for supporting digital transformation (DX) across industrial domains that has functions of monitoring, control, simulation, visualization, and prediction. However, there exist conceptual and terminological inconsistencies in DT due to industrial heterogeneity and technological complexity. We conduct patent-based network analysis to develop a technology reference model for DT technologies in order to uncover the core enabling technologies and technological structure. Two types of network analysis, co-word and co-citation, are constructed based on the 1201 DT-related patents. The co-word network analysis identifies 13 technology clusters, and the co-citation network analysis reveals 16 technology clusters. The combined results yield 17 technology components structured into three layers: (a) enabling technology, (b) core functionality, and (c) service according to technological role. A DT technology reference model is then developed based on the structured technology components. The proposed DT technology reference model offers comprehensive insights into the landscape of DT technologies and serves as a guide for researchers and policymakers seeking to systematically understand DT technologies for the DX paradigm.