Flexible Design of EGB Structure for Antenna Appliations

Abstract

In  this paper,  we  present  a  flexible  design of  electromagnetic  bandgap  (EBG)  structure,  which  is constructed  based  on  Fractal  geometry,  for  antenna applications.  These  Fractals,  which  are  the  Sierpinski triangles,  are  arranged  to  repeat  each 600to  introduce the  hexagonal  unit  cells.  By  changing  the  gap  between two adjacent Sierpinski triangles inside EBG unit cell, it can  be  introducing  two  EBG  structuresseparately  that have  broadband  and  dual  bandgap.  By  using  the suspending  microstrip  method, two arrays 3×4  of  EBG unit  cells  areutilized  to  investigate  the  bandgap  of  the EBG  structures.  The  EBG  operation  bandwidth  of  the broadband  structure  and  the  dual-band  structure  are about  87%  and  40%;  35%  at  the  center  bandgap frequencies,  respectively.  Moreover,  a  comparison between  the  broadband  EBG  and  the  conventional mushroom-like  EBG  has  been  done.  Experimental results  of  the  proposed  design  show  good  agreement  in comparison  with  simulation  results.  Finally,  the proposed  EBG  structures  are  studied  as  a  high impedance  ground  plane  for  enhancing  the  radiation properties of a patch antenna.