Slow-wave microstrip line on nanowire-based alumina membrane

This paper proposes a new technology for slow wave microstrip lines based on a low-cost metallic-nanowire-filled-membrane substrate (MnM-substrate). These transmission lines can operate from RF to millimeter-wave frequencies. The MnM-substrate consists in a dielectric material containing vertical metallic nanowires connected to a bottom ground plane. The innovative concept of the slow-wave microstrip lines on MnM-substrate is presented, as well as the electromagnetic considerations, fabrication process, and measurement results. Initial results show high relative dielectric constants (up to 43). Hence, it is possible to reach high-quality factor transmission lines within a great range of impedances, from 20 to 100 Ω, without critical dimensions.