3-D Printed W-Band Waveguide Twist With Integrated Filtering

This work demonstrates the integration of a lowpass filter into a 90(?) waveguide twist at W-band (75-110 GHz), manufactured using polymer-based 3-D printing. For the first time, a 1-D periodic electromagnetic bandgap (EBG) structure is incorporated within a waveguide twist. Unlike conventional filters, implemented using irises and septa, EBG structures employing hollow cavities are structurally robust and mechanically insensitive to 3-D printing. The measured average passband insertion loss is only 0.48 dB at the W-band while using our unconventional split-block solution (H-plane a-edge split with raised lips). A nontwist thru filter has also been demonstrated, as a reference. Our approach demonstrates the potential for the low-cost manufacture of compact and high-performance multifunctional integrated waveguide components at millimeter wave frequencies.