The development of interconnections suitable for radio- frequency (RF) and millimeter-wave (mm-wave) applications is of foremost importance for the feasibility of high-quality substrate-integrated devices. For this purpose, we introduce and validate the technology to implement fine-pitch high- aspect ratio tungsten-filled through-silicon vias (W-TSVs) adapted for high-frequency applications. The presented technology is optimized for integration with RF MEMS, for which we propose a compatible fabrication process flow. We designed and characterized RF test structures to assess the quality of the W-TSVs and their suitability for radio- frequency integrated circuits (RFIC) applications, showing low insertion loss for TSV in coplanar waveguides (CPW) and high-performance wideband mm-wave antennas.