Here is the abstract you requested from the rf_2008 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Electromagnetic Bandgap Structure Integrated within an LTCC Package For Millimeterwave Parasitic Mode Suppression|
|Keywords: parasitic mode suppression, EBG structures, LTCC packages|
|Many microwave and millimeterwave systems require shielded packages with metal covers and sidewalls for EMI and EMC reasons. A major design issue is that parasitic resonant modes can be excited inside shielded packages or enclosures. Significant loss of system performance can occur at these resonant frequencies. This contribution focuses on the use of millimeterwave electromagnetic bandgap (EBG) structures in LTCC packages where an air gap exists between the ceramic base and lid. The EBG structure is a periodic metallic array of vias and patches which may be fabricated as an integral part of the base and the lid of a two-part ceramic package. To the author’s knowledge, this is the first reported work of an EBG structure that is integrated into both the lid and base of a package. The exterior metal shielding layers of the package form a parallel-plate waveguide that ordinarily supports propagating electromagnetic modes. The introduction of the EBG structure will suppress propagation of these modes over a limited band of frequencies regardless of the direction of propagation. In this paper, we present simulated results for EBG structures designed for parasitic mode suppression over the IMS band at 24 GHz. A typical period of an isotropic unit cell is only 500 um, allowing multiple unit cells to be designed into conventional LTCC package sizes. Various examples of EBG structures will be shown where the periodic structures are designed into only the package lid, or into the base and the lid of the package. The later case will be shown to have a wider stopband and greater attenuation. The impact of different cover heights on stopband performance will also be presented.|
|William E. McKinzie III, President