Study of microwave electromagnetic radiation in multilayer QFN package

Electromagnetic radiation from parallel-plate planes of power-return and ground pairs are investigated. Such structures are widely used in microwave multilayer packages and could be the source of considerable electromagnetic interference (EMI) or simultaneously switching noise (SSI). Effective methods should be applied for damping and elimination of the radiated fields, especially in small areas and volumes. The developed threelayered LTCC microwave package possesses two separate grounding planes on different levels, connected through multiple vias. Estimation of the electromagnetic field distribution and radiation pattern is conducted by full-wave analysis. The article discusses the influence of the vias grid layout on the performance of an exemplary multi-port structure in the frequency band of interest - 10 to 30 GHz.