Analysis of Different Defect Configurations in CEBG Structures for Directive Patterns Arezou Edalati, Tayeb A. Denidni, and Halim Boutayeb INRS-EMT, University of Quebec, Montreal, Canada.

CEBG principle CEBG: Cylindrical electromagnetic band gap, Radially and circularly periodic, Feed in the centre, Present pass-band and stop-band to cylindrical EM wave, applying a defect  reconfigurable directive pattern, Defect can be create by using active element

EBG structure CEBG Structure

Previous work: applying horn-shape defect for reconfigurable directive pattern Advantage: 360 degree turning of the radiation pattern draw back: need a lot of diodes (all the wires have to loaded with active element and more power supply CEBG antenna with horn-shape defect LwLw w a Active components (ex.: Diodes) Reconfigurable EBG structure

Solution1 previous work structure composed of discontinuous metallic wires, defects consisting of continuous wires. Advantage: Reduction the power supply dc current by 75% Drawback: Narrowband Number of diode is the same

Solution 2 Apply different defect configuration

Directivity of different configuration far-field proprieties are investigated through an examination of the two- dimensional directivity Ez is the transverse component of the total electric field in the far filed region, calculated with the FDTD method

Directivity vs. Frequency

Radiation Pattern HornDefect 1

Defect 3Defect 2 Radiation Pattern

Defect 5 Defect 4 Radiation Pattern

Conclusion The best defect configuration is Defect1 in term of radiation pattern, directivity and band width 60% reduction of active element and power supply compare to Horn configuration They have almost the same band width