Design Of LTCC Filters

LTCC(Low Temperature Co-fired Ceramic) is a newest way of high frequency layout technology with the characters of three-directions which makes a great difference to the design method between LTCC filters and traditional microstrip or stripline filter. Many layers of metal strip in this multi-layer structure are planted inside the LTCC unit or model. There are horizontal coupling between strips in the same layers and vertical coupling between strips between different layers. Then, greater flexibility than traditional microstrip and cavity can be gotten by LTCC technology. Units and models with particular performance, smaller volume and less power consumption can be designed with LTCC.This thesis mainly about the design methods and process of LTCC filters. Based on the traditional filter design theory, circuit of the filter is decided in advance. Then every elements of the circuit are designed in LTCC one by one. Finally, they are connected to simulate and tune by 3-D EDA software. The method of designing a discrete LTCC filter is based on the traditional filter design theory, too. After altering the traditional theory and formulae to meet the actual LTCC manufacture condition and constructing a usable structure, the discrete filter can be designed and tuned by EDA software using a DOE (Design Of Experiments) method.By these methods, a lumped filter and a discrete filter are designed and tested. A good agreement between the simulated filters and manufactured ones are shown by the result which proves the reliability of these design methods.