Ultra-Wideband LTCC Ridge Waveguide Filters

The design and experimental validation of an ultra-wideband (UWB) filter in a low temperature co-fired ceramic (LTCC) is presented. The bandpass filter uses ridge waveguide resonators realized in LTCC by printing parallel planar conductors for the top and bottom walls and closely spaced metal filled vias for the lateral walls. Filter coupling scheme and stripline transitions are developed for the UWB requirement. The mode-matching method is used in their design. The LTCC via effect and the measurement setup are also addressed. Finally, experimental results of a nine-order filter (design passband from 3 to 9GHz) are presented