Monolithic 3D printed waveguide filters with wide spurious‐free stopbands using dimpled spherical resonators

Employing a family of dimpled and slotted spherical resonators, set X-band waveguide bandpass filters (BPFs) is presented in this study. The resonators originated from with depression (hence, dimples are formed) cutting slots into the resonator shell. With large number experiments, combination using twisted coupling topology, slotting on results simultaneous low insertion loss (IL), good out-of-band rejection wide spurious-free stopband. Several BPFs designed 3D printed selective laser melting (SLM) technique where they made one piece. monolithic implementation these allowed by compatibility microwave mechanical design, which minimises required supporting structures inside filters. measurement show ILs 0.2–0.3 dB better than 15 return loss. There small frequency shift less 0.9%, measured stopband covering entire X–Ku bands (8.2–18 GHz) over 34 dB. Additionally, for SLM devices, influences temperature to S-parameter responses, as well polishing, lowers losses, included