Improvement of characteristics using cross patch in the LTCC filter

A TE/sub 10/ mode dielectric LTCC (low temperature co-fired ceramic) filter using a cross patch is proposed. The LTCC filter is designed as a lumped circuit without a cross patch. The filter is designed by lumped elements and converted to an LTCC filter. The characteristics of the filter are simulated by finite element methods (FEM). The center frequency of the filter is 6 GHz; and the bandwidth is 500 MHz. The simulated results of the filter are compared with the experimental ones and agree well. An LTCC filter, using the same design procedure, is applied to one using a cross patch. This cross patch is useful for making the attenuation poles. It works as the TEM transmission in the LTCC filter. As a result, it realizes an attenuation pole. An LTCC filter using a cross patch is designed at a center frequency of 25 GHz.