Homogenization models for the analysis of reflection properties of mushroom structures

1 Department of Radio Science and Engineering / SMARAD Center of Excellence, TKK Helsinki University of Technology, P.O. Box 3000, FI-02015 TKK, Finland, email: olli.luukkonen@tkk.fi 2 Department of Electrical Engineering Instituto de Telecomunicacoes, University of Coimbra, 3030 Coimbra, Portugal 3 Department of Electrical Engineering, University of Mississippi, University, MS 38677, USA Abstract