Research on reflection phase characterizations of artificial magnetic conductors

In this paper, several kinds of artificial magnetic conductors (AMC) with rectangular lattices such as mushroom-type and UC-PBG high impedance surfaces (HIS), square patch and square loop frequency selective surfaces (FSS) are analyzed. The sensitivity of reflection phase with the incident angle is compared among them, and the results show that loop-FSS with smaller period has least sensitivity to the incident angle. Furthermore, the reflection coefficients of each AMC structure change significantly when the incident angle is larger than 30°. As a countermeasure, the units at edge of the AMC surface, used as a ground plane of antenna, may be modified in sizes for compensating their reflection phase.