Design of LTCC Filters Using a Cross Patch


IEICE TRANSACTIONS on Electronics   Vol.E86-C   No.12   pp.2412-2416
Publication Date: 2003/12/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Recent Trends on Microwave and Millimeter Wave Application Technology)
Category: Passive(Filter)
dielectric waveguide filter,  LTCC,  attenuation pole,  cross patch,  

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A conventional waveguide filter is usually composed of a waveguide which is set with irises and posts inside. When dielectric material is not loaded inside the filter, the filter is too large to mount it on a planar circuit even if the frequency band is as high as the millimeter-wave band. In this paper, we propose a dielectric waveguide filter using LTCC (Low-Temperature Co-fired Ceramics) which can be mounted on a planar circuit. The dielectric waveguide filter using LTCC is composed of a dielectric-loaded waveguide including posts (via holes) and TEM-TE10 converters. The design method of the filter is shown and comparison of the simulated and the experimental results in the 6 GHz band is demonstrated. The simulated results agreed well with the experimental ones. To improve the attenuation characteristics, particularly at the above pass-band frequencies, an attenuation pole is added using a cross patch set inside the LTCC filter in the 25 GHz band. The effect of the cross patch is confirmed using the same simulation method as used for the 6 GHz band. As a result, it is confirmed that the cross patch is very useful for improving the attenuation characteristics at the above pass-band frequencies.