Authors
Izabela Stępińska
Tele and Radio Research Institute, Ratuszowa 11, 03-450, Warsaw, Poland
Elżbieta Czerwosz
Tele and Radio Research Institute, Ratuszowa 11, 03-450, Warsaw, Poland
Mirosław Kozłowski
Tele and Radio Research Institute, Ratuszowa 11, 03-450, Warsaw, Poland
Halina Wronka
Tele and Radio Research Institute, Ratuszowa 11, 03-450, Warsaw, Poland
Piotr Dłużewski
Institute of Physics PASc., Al. Lotników 32/46, 02-668, Warsaw, Poland