Abdalla, Mahmoud AWahba, Walaa WEl Atrash, Mohamed2021-12-242021-12-2419/09/2021https://doi.org/10.1080/00207217.2021.2001858https://bit.ly/3ppl0DbProposed in this paper is a new configuration for a quad-band antenna based on using a metamaterial-inspired defected ground structure. The presented structure is introduced as a new modified metamaterial Complementary Split Ring Resonator (CSRR) with a compact electrical size. The new modified CSRR has been employed in Composite Right/Left-Handed (CRLH) transmission line config- uration for ultra-size reduction. Validation for the particle small size is introduced and the detailed analysis for the NRI characteristics has been discussed by extracting the cell constitutive parameters. Hence, a multi-band antenna is designed based on using only one cell of the proposed NRI-TL. Subsequently, a small multi-band antenna is presented for different multi-band functionalities and different radiation properties. The antenna displays quad-reso- nances at 1.78 GHz, with the typical omnidirectional radiation pattern, 3.28 GHz, 4 GHz, and 4.3 GHz, with the directive broadside radiation properties. The proposed antenna footprint is 10 × 10 cm2 , which exhibits a size reduction of up to 80% in comparison with a rectangular patch antenna operating at the lowest frequency band.en-USMetamaterialcomplementary split-ring resonatordefected groundcomposite right/left-handedquad-band antennaArticlehttps://doi.org/10.1080/00207217.2021.2001858