An Antenna Array Approach for Propagation of Electromagnetic Waves - PowerPoint PPT Presentation

An Antenna Array Approach for Propagation of Electromagnetic Waves Author: António E. M. S. Casimiro Email: acasimi@ualg.pt Affiliation: Science and Technology Faculty-CEFAT, University of Algarve, Mailing address: Campus de Gambelas, 8000-117 Faro, Portugal Effort made in the framework of COST 296, sponsored by the Air Force Office of Scientific Research, USAF, and presented at the 2nd COST IC0603 Workshop as a COST cooperation activity. COST IC0603 Workshop, 9-11 April 2008 Limassol, Cyprus

The Huygens principle COST IC0603 Workshop, 9-11 April 2008 Limassol, Cyprus

The “array approach” Phase shift with sinusoidal waves "virtual antenna" v 1 � medium 1 1 f 2 � d sin � 2 d (d)= d= � � 2 � 2 medium 2 v 2 � 2 f � 2 COST IC0603 Workshop, 9-11 April 2008 Limassol, Cyprus

The shift in the Fourier Transform F A( � ) A(d) <--------> F d � � ) A(d)e A( ��� 2 <--------> 2 COST IC0603 Workshop, 9-11 April 2008 Limassol, Cyprus

The Fourier Relation = 2 � sin � 2 2 � � A 2 � A � 2 � � F d � e j � d A A F � � d � (the particular case of transversal � and endfire arrays) COST IC0603 Workshop, 9-11 April 2008 Limassol, Cyprus

The shift in the “antenna” pattern A 2 � 2 � 1 = � � � 1 1 medium 1 � 1 � sin � 1 = � 2 sin � 2 > � 1 � 2 1 > � 2 � 1 v n 2 sin � 1 = � 1 1 = v 2 = n � � 2 sin � 2 1 � 2 medium 2 � 2 2 � 2 � � = - � � 2 2 2 COST IC0603 Workshop, 9-11 April 2008 Limassol, Cyprus

The Snell’s law � 1 n medium 1 v n 2 = v 2 1 sin � 1 1 = n sin � 2 n 2 1 medium 2 � The Snell’s law does not take 2 in hand the reflected ray COST IC0603 Workshop, 9-11 April 2008 Limassol, Cyprus