1. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 1 Gain Enhancement of a Dielectric Resonator Antenna Using a Cylindrical Electromagnetic Crystal Substrate Yacouba Coulibaly, Yacouba Coulibaly, Halim Boutayeb and Tayeb A. Denidni

2. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 2 Introduction Antenna Configuration Simulation Results Measurements Conclusion Outline

3. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 3 Inconvenient of a Dielectric Resonator Antenna: low gain Introduction Advantages of a Dielectric Resonator Antenna (DRA)  Low losses  Reduced sized  High radiation efficiency  High density integration

4. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 4 Introduction (cont.) To improve the radiations characteristics of the DRA, few studies have been proposed: The DRA has been placed on different ground planes shapes Coaxially corrugated. Strip corrugated. Mushroom-like Electromagnetic Bang Gap (EBG) substrate.

5. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 5 Introduction (cont.) Design Objectives  Use a circularly periodic EBG to increase the gain of a cylindrical DRA.  Exciting the fundamental mode  Have the same radiation pattern shapes with or without the EBG substrate

6. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 6 Antenna Design Description: A Dielectric Resonator (DR) : The DRA has a radius R=15mm, a height h d =10.5mm,and a permittivity ε dra =31.5.. A Coaxial feed line: The coaxial line is at a distance of 9 mm from the center. A circular EBG : Printed on a substrate of permittivity ε 2 =2.2 and thickness h=3.2mm. The distance from one strip to the following one is g=2mm. The periods for the strips is P r2 =24.6mm. The metallic via have a radius a=2mm, and they are disposed with the same transversal period and the same radial period P r2 =23.6mm.

7. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 7 Simulated return loss (with Ansoft HFSS)of the antenna with and without the EBG substrate Simulated return loss (with Ansoft HFSS) of the antenna with and without the EBG substrate Simulated results

8. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 8 Simulated gain (with Ansoft HFSS) of the antenna with and without the EBG substrate Results: The gain is increased by 3 dB due: to the reduction of the surface waves. to the coupling between the DRA and the circular EBG (mainly). Simulated results (cont)

9. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 9 Simulated radiation patterns at 2.25 GHz, in both the E- and H-Plane, with and without the EBG substrate Results: The EBG structure improves the gain The back radiation decrease Simulated results (cont)

10. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 10 Experimental results Photographs of the fabricated antenna prototypes DRA alone DRA with cylindrical EBG substrate

11. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 11 Experimental results Measured return loss of the antenna with and without the EBG substrate Network Analyzer

12. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 12 Experimental results (cont) Measured gain (in an anechoic chamber at INRS) with and without the EBG substrate

13. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 13 H-plane E-plane Measured radiation patterns with and without the EBG substrate Experimental results (cont)

14. INRS- Énergie Matériaux Télécommunications Montréal, Québec, Canada 14 The gain enhancement of a DRA has been investigated and good performances have been achieved By adding the EBG substrate, the radiation characteristics have been significantly improved The coupling between the cylindrical DRA and the reduction of the surfaces waves enhance the gain of the antenna Conclusion Perspectives: Investigation of elliptical EBG structures; Design of elliptical patch antennas and elliptical DRAs integrated on elliptical EBG substrates, for Satellites communications applications (circular polarization).