Electromagnetic band-gap (EBG) structures using combined inductive and capacitive elements and chirping-and-tapering technique

Purpose - To perform studies and comparisons on the electromagnetic band-gap (EBG) structures, which are constructed by using a combination of inductive and capacitive elements printed on guided-wave transmission lines, and by applying a chirping-and-tapering technique.Design methodology approach - An in-house solver based on finite-difference time-domain (FDTD) method is adopted for analysis. Conventionally, EBG characteristics are formed by a series of perforations, considered as capacitive elements, on the ground plane(s). To enhance the performance, an additional inductive element is implemented, which is realized by narrowing the strip over the respective perforated regions. For further enhancement, a chirping-and-tapering technique is applied on the combined EBG structures for comparisons.Findings - Through scattering parameter analysis, it was found that the EBG structures using combined inductive and capacitive elements exhibit a band-gap behavior superior to the ones built with only inductive or capacitive elements. In another set of comparisons, the modified EBG structures combined with a chirping-and-tapering technique resulted in further widening of band-gap, as well as lower side-lobes and a smoother transition towards the band-gap region.Research limitations implications - Research was mainly limited to studying solely the EBG structures printed on guided-wave transmission lines.Practical implications - The proposed EBG structures may be applied into various areas, such as microelectronics and mobile communications for harmonic suppressions, and into other practical electronic circuit structures.Originality value - The ideas on applying combined inductive and capacitive elements on various guided-wave transmission lines to induce EBG characteristics, together with applications of a chirping-and-tapering technique on the combined EBG structures give rise to the research originality.