A compact MIM zeroth order resonator antenna

In this paper a compact μ negative zeroth order resonator (ZOR) antenna using metal-insulator-metal (MIM) structure is presented. The μ negative (MNG) and ε negative (ENG) transmission lines (TLs) are artificial TLs which have been introduced recently. These transmission lines are simpler than the composite right/left handed (CRLH) TL while, similar to CRLH TL, they can be used as zeroth order resonators. MNG ZOR antenna has been previously introduced based on an interdigital structure which is fed by a microstrip line in parallel with the antenna. The MNG ZOR antenna presented in this paper is based on the MIM structure which has some advantages over the interdigital structure. In addition, we use a coaxial feed and a specific matching mechanism which, in comparison with the previous work, leads to the more compact antenna and also lowers the cross-polarization level.