“Multi-Ring 4×4 UWB–X–Ku MIMO Antennas for High-Resolution Microwave Imaging: A Review”. Journal of Intelligent Engineering and Informatics 1, no. 1 (September 29, 2026): 121–130. Accessed September 29, 2026. https://www.journaliei.org/index.php/jiei/article/view/18.