A300 GHz Waveguide Cavity Filter Fabricated by 3D Screen Printing Technology

This paper presents a waveguide cavity filter fabricated in metal by three-dimensional screen-printing technology. The bandpass filter operates at 300 GHz with a fractional bandwidth of 9%. The filter has a back-to-back structure formed of five capacitively coupled waveguide cavities and two right-angle bends. The filter was made of tungsten-copper (W-Cu) and it was additively built, forming a monolithic device. The as-printed filter initially had a slight curvature that was later straightened using heat treatment to allow better connection between the device and the flanges of the test ports. The measured minimum bandpass insertion loss was 3 dB, with a return loss better than 11 dB. This paper also presents characterization results of the manufactured samples using X-ray computer tomography and optical microscopy.