Investigation on resonance and radiation properties of rectangular microstrip antennas with partially filled metamaterial substrates and superstrates
In this article, the effect on the resonance and radiation characteristics of a rectangular microstrip patch antenna partially loaded with inhomogeneous substrates and superstrates consisting of ?-negative (MNG) and double-negative (DNG) metamaterials are investigated. It is observed that the size of the DNG and MNG material regions of the substrate influences the antenna gain and can be used to tune the resonant frequency as well as the bandwidth. Embedded DNG substrate blocks placed on either side of the radiating edge of the antenna results in increasing the gain to about 10 dBi and in dual-band resonance characteristics. Embedded MNG substrate resulted in gain enhancement to about 9.50 dBi. DNG materials used as superstrates result in dual-band operation with similar gain in both bands, whereas a MNG superstrate leads to improved impedance bandwidth. Moreover, dual-band characteristics can be achieved with almost the same realized peak gain in both bands, by using an optimum proportion of MNG and DNG materials as substrate.  2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE 22:558568, 2012.
microstrip antennas metamaterials dispersive media