Design and manufacturing reliability of passive components for LTCC millimeterwave hybrid circuits

The design reliability of LTCC circuits up to millimeter wave frequencies and the tolerances associated with the manufacturing process are studied. Representative circuit elements are analyzed, i.e. a planar bandpass filter, a buried DC-block filter and a vertical DC-feed network, which take advantage of fine line printing and high permittivity layer inclusions. In order to distinguish between manufacturing tolerances and variations occurring during the measurement, a reference sample method is introduced. All samples show good to excellent agreement with simulations as well as very little manufacturing variations up to 40 GHz.