A H-Band Direct Laser Written Leaky-Wave Fed GRIN Lens Antenna

Lens antennas are commonly used for communication and imaging applications in the terahertz band and are often fabricated from high-resistivity silicon due to its low dielectric loss. Drawbacks to silicon lens antennas are that they can be bulky, expensive and require specialized fabrication processes (e.g. DRIE). Additionally, silicon lens antennas are susceptible to Fresnel reflection losses and exhibit a strong Fabry-Perot response, primarily due to the high dielectric constant of silicon. A lower cost solution is to develop a polymeric lens antenna which can be fabricated using 3D printing processes. However, conventional 3D printing techniques (e.g. FDM and SLA) have limited resolution and cannot meet the fabrication tolerances required for operating frequencies above several hundred gigahertz. An alternate approach is to use Direct Laser Writing (DLW) based on Two-Photon Polymerization (2PP) of a photoresin (PR) which combines sub-micron fabrication accuracies with the ability to realize complex 3D geometries. A limitation of this approach is the typically high dielectric loss of the available PRs in the terahertz band.