Dual-mode compact microstrip antenna based on fundamental backward wave

In this paper, a dual-mode compact microstrip antenna based on the fundamental backward wave supported by a composite right/left-handed (CRLH) metamaterial transmission line (TL) is demonstrated. The physical size and operational frequencies of the antenna are determined by the CRLH metamaterial´s unit-cell. This antenna is capable of monopolar radiation at one resonant frequency and patch-like radiation at another resonant frequency. Numerical and experimental results of a three unit-cell CRLH-based antenna are used to verify the authors´ claims.