Metal additive manufacturing processes, such as laser beam melting (LBM), can play a key role in developing antenna-feed chains because monolithic and multifunctional parts can be manufactured with high geometric freedom in the design phase. Using LBM technology, lighter and more compact antennas can be produced and manufacturing costs can be reduced. However, the surface roughness of internal surfaces in waveguides produced by LBM is much higher (about 10 μm Ra) than that produced by conventional manufacturing technologies. Consequently, such high surface roughness of the internal surface can affect electrical current propagation through the waveguide and corresponding transmitted power. In this paper, abrasive flow machining (AFM) was used to reduce the surface roughness of the internal surfaces of four different waveguides used at both K and Q bands. A significant reduction in the transmission loss at both K and Q bands was observed as their internal surface roughness decreased from about 10 μm to 1 μm Ra. This was assumed to be due to an increase of the internal surface electrical conductivity with the decrease of roughness in waveguides channels.

金属增材制造工艺，如激光束熔化 (LBM)，可以在开发天线馈电链中发挥关键作用，因为可以在设计阶段以高几何自由度制造单片和多功能部件。使用 LBM 技术，可以生产更轻​​、更紧凑的天线，并降低制造成本。然而，LBM 制造的波导内表面的表面粗糙度要高得多（约 10 μm Ra) 比传统制造技术生产的产品。因此，内表面的这种高表面粗糙度会影响通过波导的电流传播和相应的传输功率。在本文中，使用磨料流加工 (AFM) 来降低在 K 和 Q 波段使用的四种不同波导的内表面的表面粗糙度。观察到 K 和 Q 波段的传输损耗显着降低，因为它们的内部表面粗糙度从大约 10 μm Ra降低到 1 μm Ra。这被认为是由于内表面电导率随着波导通道粗糙度的降低而增加。