Effects and Models of Offset-Via in Electromagnetic Band Gap Structure

Via is an essential component in the design of an Electromagnetic Band Gap (EBG) structure. This paper investigates the effects of the via in a mushroom-like EBG structure and proposes an equivalent circuit model of the via. It is revealed that when the via in the mushroom-like structure is offset, the element reflection phase will vary within 720 degrees instead of 360 degrees phase range in a conventional design. This phenomenon can be explained by a new circuit model that introduces a mutual inductance, and the corresponding electromagnetic properties of mushroom-like EBG structure can be quantitatively analyzed by this model. In addition, the applicability and error analysis of the model are discussed in this paper. The theoretical modeling and analysis enable an efficient and in-depth exploration of the via functions in similar EBG structures, and also provide more theoretical guidance and assistance for the design of reflection and transmission units based on EBG structure.