1- I found formulas for mushroom like ebg , if it is considered as a filter LC
band width of ebg bw = 1/n (sqrt (L/c) n:impedance free space
and L has its forumule also C (capacity)
can be based on its formulas very simple for design ebg mushroom?
2-for array patch application , ebg is used to delete surface wave , but in certain publication , he said "...band gap is higher than the resonant frequency fr. Therefore, the mutual coupling is not reduced..."
to impose the bandgap of ebg , normally we should be based on the frequency of surface waves , and not on the resonance frequency of the patch antenna ,...???