El-Shaarawy, H. B., F. Coccetti, R. Plana, E. M. Said, and E. A. Hashish,
"Compact Bandpass Ring Resonator Filter With Enhanced Wide-Band Rejection Characteristics Using Defected Ground Structures",
IEEE Microwave and Wireless Components Letters, vol. 18, issue 8, pp. 500 – 502, 2008.
El-Shaarawy, H. B., F. Coccetti, R. Plana, M. E. Said, and E. A. Hashish,
"Compact reconfigurable defected ground structure (DGS) based multi-band bandpass filters on coplanar waveguide technology",
IEEE Asia Pacific Microwave Conference (APMC 2009), Singapore, 7 – 10 Dec, 2009.