Optimizing the Gain and Directivity of a Microstrip Antenna with Metamaterial Structures by Using Artificial Neural Network Approach. - Metin Sagik; Olcay Altintas; Emin Ünal; Ersin Özdemir; Mustafa Demirci; Sule Çolak; Muharrem Karaaslan (Wirel. Pers. Commun., 2021)