Defense Session of PhD Thesis

  Abstract

  In this thesis some electromagnetic bandgap(EBG) structures such as defected microstrip structure(DMS) , cacadesd defected microstrip structure(CDMS) and defected ground structure(DGS) are analyzed and modeled by some new approaches. The physical dimensions and how current circulations are used for modeling. The frequency responses of proposed models show good agreement with full wave simulations. To verify these models, the comparison in response not only has been considered in amplitude but also in phase of all S-parameters of proposed model and full wave analysis. Also some modeling results are validated simultaneously by comparison with simulations of the structures and experimental results.

  Throughout the thesis many new applications for DMS, CDMS and DGS such as all types filtering, noise and harmonic suppressing, improvement input impedance of narrow and broad band microstrip antenna, very compact filter called island DMS (I-DMS) with more than 900% compactness, millimeter filter design and so on are introduced. Also to model these structures, some useful formulas are extracted to obtain the lumped element parameters. Also the error diagrams are presented for better comparison.

  Place: Seminar Room of Electrical Faculty