Impedance analysis of extremely low-profile antennas using metamaterial substrates

Low-profile antennas are desirable in personal communications due to attractive features such as low cost, light weight, conformability, and ease of integration. A major challenge in low-profile antenna design is the trade off between the (reduced) antenna profile and performance. This trade-off can be ameliorated by loading the antennas with properly designed metamaterials. In this paper, we explore the use of a new anisotropic metamaterial as antenna substrate and examine its effect on the input impedance of two types of low-profile antennas. We have shown that height reduction can be achieved without significant change on the antenna input impedance.