Size reduction of a microstrip antenna with dielectric superstrate using meta-materials: artificial magnetic conductors versus magneto-dielectrics

Planar antenna gain can be enhanced using a high-permittivity cover as the superstrate (D.R. Jackson and N.G. Alexopolous, 1985). As well, partially reflecting sheets (PRSs) have been used as the superstrate layer for gain enhancement (T. Zhao et al., 2005). In addition, artificial magnetic conductors (AMCs) as the ground plane have been able to reduce the microstrip antenna size with a PRS cover (A. Fresidis et al., 2005). On the other hand, a class of novel materials called magneto-dielectrics has recently been introduced which can simulate both high permittivity and permeability, while being low-loss (H. Mosallaei and K. Sarabandi, 2004) (A. Buerkle and K. Sarabandi, 2005). Thus, these novel materials hold promise in antenna miniaturization (H. Mosallaei and K. Sarabandi, 2004) (A. Buerkle and K. Sarabandi, 2005). In this paper, initially a conventional microstrip antenna with the high-permittivity dielectric superstrate is designed. Then, using a periodic structure of metallic patches, acting as an AMC, the antenna size is reduced. Furthermore, another size reduction method for this class of high-gain antennas is proposed using magneto-dielectrics. The results are presented and discussed