Fabrication and Its Characteristics of Ka-Band Electroplated 3D Printed Waffle Type Waveguide

We report the fabrication results and its characteristics of Ka-band waffle type waveguide. The waffle type waveguide consists of electromagnetic wave transmission part and low pass filter parts. The incident electromagnetic waves having lower frequencies than a designed cut-off frequency travel into the low pass filters. Then, the electromagnetic waves having higher frequencies than a designed cut-off frequency only transmit through the waveguide. We verified the operation of the designed waffle type waveguide. In this study, in the fabrication of the waffle type waveguide, to obtain a low-cost and high-speed manufactured waveguide, we used a resin 3D printing technique by fused deposition modeling method. Moreover, to obtain a low insertion loss waveguide, the 3D printed waveguide was deposited with 10 µ m thick Ag electroplated layer after electroless plated seed layer. In S-parameter measurement, we obtained the insertion loss of -3.2 dB at 28 GHz. To improve the characteristics, the 3D printing method was changed to stereolithography method, and we sprayed Ag paste as seed layer for better adhesion of the Ag electroplated layer.