NISAA YASMIN BT NOR IZUDDIN; OSMAN BIN AYOP; FARID BIN ZUBIR. A Comparative Study of Four Defected Ground Structures for Ultra-wideband Planar Antenna Application at 3.5 GHz. ELEKTRIKA- Journal of Electrical Engineering, [S. l.], v. 24, n. 2, p. 98–103, 2025. DOI: 10.11113/elektrika.v24n2.556. Disponível em: https://elektrika.utm.my/index.php/ELEKTRIKA_Journal/article/view/556. Acesso em: 5 dec. 2025.