PTFE-Core Flexible Waveguide and Application to High-Data-Rate Interconnects at 80 GHz

This paper presents the design and experimental validation of a flexible/low-loss waveguide, operating in the single-mode condition from 70 GHz to the upper part of the E-band <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(86 \text{GHz})$</tex>. The waveguide's design and geometric parameters were numerically optimized using EM simulations. The fabrication is done using industrial-grade machines for PTFE extrusion and metal ribbon deposition. Performances of the waveguide are presented (effective index and losses), using vector network analysis in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$70-110 \text{GHz}$</tex> range. The flexible waveguide is also used as a flexible interconnect for millimeter-waves: in this work, 48 Gbit/s transmission is obtained using a QAM-64 signal centered at 80 GHz.