Integrated waveguide bandpass filters using thick-film technology

By integrating planar circuits, such as a microstrip line, and the rectangular waveguide with inductive posts onto the same substrate, the low-loss bandpass filter can be realized without resort to tuning or mechanical mounting. However, the design and performances of the filter are limited by the conventional PCB process restrictions, such as constant via-holes diameter and material characteristics. In this paper, a singlesubstrate integrated waveguide bandpass filter operating in UNII band is realized using thick-film technology