IEEE ACCESS, vol.11, pp.42234-42247, 2023 (SCI-Expanded)
Electromagnetic Bandgap (EBG) structures that exhibit various performances, such as preventing the electromagnetic wave propagation and reflecting an incident wave within the stopband, have unique
electromagnetic characterization. Due to this reason, accurate analysis and design of the EBG structures
are crucial to enhance the integrated system performance. This paper concentrates on the characterization of
some planar EBGs using the Auxiliary Functions of Generalized Scattering Matrix (AFGSM) methods, with
particular importance on an in-depth consideration of its bandgaps. The AFGSM method is applied to the
planar EBG structures in the literature for the first time. The well-known kinds (symmetric and asymmetric
cases) of mushroom type and multilayer EBG structures are considered to verify the presented method.
Analysis results are compared with the Conventional Eigenvalue Equation (C-EIV) and the Generalized
Scattering Matrix based Eigenvalue Equation (GSM-EIV) methods. Low computation load and accurate
results are obtained to analyze the planar EBG structures with the AFGSM method due to using transmission
line model. In addition, a design methodology is proposed for a chosen planar EBG structure using the
AFGSM methods. Geometrical parameters of interested EBG problems are determined for acquiring the
stopband frequency region of interest using the scattering parameters of unit cell configuration. The mushroom EBG model along one and two-dimensional axes is used in an antenna application to decrease mutual
coupling between antenna elements. Three different scenarios are simulated in the HFSS electromagnetic
simulation design environment to understand the effect of mutual coupling reduction in the antenna problem
of the designed EBG structure via the AFGSM method. All designed antennas are manufactured, and
the measurement results are in good agreement with the simulation results. The measurement results of
the fabricated antenna application example including designed EBG using the proposed AFGSM method
are compared with the existing similar problems with the same and different EBG models. It has been
demonstrated that bandgap analysis, design of the planar EBG structures and integration of considered EBG
model to a design application can be accurately and quickly achieved with the given methodology using the
AFGSM method.