LTCC wide-band ridge-waveguide bandpass filters

A ridge-waveguide tap-in coupling structure is applied to the design of wide-band ridge-waveguide bandpass filters using low-temperature cofired ceramic (LTCC). The design is based on rigorous mode-matching modeling, which takes the higher order mode interactions into account. A design procedure is described and design examples are given to demonstrate the features of the proposed coupling structure. A wide-band LTCC ridge-waveguide filter is simulated and successfully built. Good experimental results are obtained.