Dayan Pérez-Quintana, University of Siena, Italy; Erik Aguirre, Eduardo Olariaga, TAFCO Metawireless, Spain; Sergei A. Kuznetsov, Novosibirsk State University, Russia; Valeri I. Lapanik, Institute of Applied Physical Problems, Belarus; Vitaly S. Sutormin, Victor Ya. Zyryanov, Kirensky Institute of Physics, Russia; Jose Antonio Marcotegui, TAFCO Metawireless, Spain; Miguel Beruete, Universidad Pública de Navarra, Spain