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

This work demonstrates the integration of a low-pass 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.