Tunable microwave metamaterial absorbers using varactor-loaded split loops Jinfeng Zhu, Delong Li, Shuang Yan, Yijun Cai, Qing Huo Liu and Timothy Lin EPL, 112 5 (2015) 54002 Published online: 22 December 2015 DOI: 10.1209/0295-5075/112/54002