V- and W-band Two-Way Waveguide Splitters Fabricated by Metal Additive Manufacturing

V-band andW-band two-way rectangular waveguide splitters are designed and fabricated using additive manufacturing by direct metal laser sintering of AlSiMg and maraging steel. The designs include a septum and tapers which improve performance but are difficult to achieve using conventional split-block machining. Standard WR-15 and WR-10 waveguide flanges are manufactured together with the waveguides and then alignment pin holes are tapped after printing. Otherwise, no post-processing is applied to the components. Measurements show that the maraging steel has better feature fabrication. The measured return loss is below 20 dB over both bands. The measured coupling ranges from 4 to 6 dB in V band and 5 to 8 dB at W band, between waveguide flanges. The estimated loss increase due to surface roughness ranges from 10.8 dB/m at 62.5GHz to 33.9 dB/m at 92.5 GHz. Measured asymmetries in the coupled port responses are explained by full-wave simulations of the actual fabricated geometry.