Polyjet-Printing-Compatible Planar Transmission Lines with Partially Air-Filled Substrate and Meshed Ground

In this study, a structural design scheme compatible with Polyjet 3-D printing technology is presented for microwave planar transmission lines (TLs), including microstrip and grounded coplanar waveguide (GCPW). The scheme involves strategically removing the dielectric substrate and meshing the ground, resulting in uniquely shaped cross-sectional profiles for these TLs. The primary goal of this design scheme is to reduce the time and cost of Polyjet-printing these TLs while maintaining their RF performance. Microstrip and GCPW prototypes with partially air-filled substrate and meshed ground are designed, manufactured, and tested. The Polyjet-printed air-filled microstrip demonstrates an attenuation factor ranging from 0.012 to 0.049 dB/mm within the frequency range of 1–6 GHz. The Polyjet-printed air-filled GCPW exhibits an attenuation factor of 0.014-0.074 dB/mm within 1–12 GHz.