Study and Design of Frequency Selective Surfaces and their Applications for Beam-Switching Antennas with Gain Enhancement.

Elzwawi, Ghada Hussain (2020). Study and Design of Frequency Selective Surfaces and their Applications for Beam-Switching Antennas with Gain Enhancement. Thèse. Québec, Doctorat en télécommunications, Université du Québec, Institut national de la recherche scientifique, 125 p.

Prévisualisation

PDF Télécharger (6MB) | Prévisualisation

Résumé

This dissertation proposes new active frequency selective surface (AFSS) elements. These unit cells have simple structures and can convert the omnidirectional radiation pattern of the antenna source into a directional one to enhance the gain and forming a new class of beam-switching antennas. A new switched beamforming antenna using a novel active triangular frequency selective surfaces (ATFSSs) is introduced. This design consists of a source of electromagnetic waves (EM waves) and a novel active triangular frequency selective surface (ATFSS) surrounding the source. By switching the embedded pin-diode between ON and OFF the omnidirectional radiation pattern of the source will be converted into a directional one. By using this design, the main beam can be steered in different directions in the azimuth plane with 120º radiation beamwidth. A novel corner-reflector antenna with a tunable gain based on AFSSs is proposed. This structure contains a dipole antenna as a source with an omnidirectional radiation pattern, and three reconfigurable AFSS layers with different sizes. The AFSS layers are arranged on the same side of the dipole and form a corner reflector. By using this design, the omnidirectional radiation pattern of the source can be converted into a directional radiation pattern with a tunable gain. To our best knowledge, it is the first time to propose a corner-reflector antenna with a tunable and variable gain directional pattern. A reconfigurable reflector antenna with beam-tilting capability (RRA) operating in the WLAN band is also presented. An array of AFSS elements and a WLAN-band patch antenna are used to design this structure. A mechanical beam tilting technique is also applied to the proposed antenna. This technique has the ability to tilt the main beam without adding any extra layers or setups to the main structure. As far as we know, this structure is the first design where AFSS is used to provide the beam reconfigurability when AFSS is arranged in a parabolic shape. To validate the concept of all the proposed antennas, the prototypes of these antennas are fabricated and measured. A good agreement between simulations and measurements in terms of beam directions, reflection coefficient, and gain has been achieved.

Type de document:	Thèse Thèse
Directeur de mémoire/thèse:	Denidni, Tayeb A.
Mots-clés libres:	télécommunications
Centre:	Centre Énergie Matériaux Télécommunications
Date de dépôt:	15 oct. 2021 13:22
Dernière modification:	15 oct. 2021 13:22
URI:	https://espace.inrs.ca/id/eprint/12049

Gestion Actions (Identification requise)

Modifier la notice