Wideband high-gain antenna using metamaterial superstrate with the zero refractive index

A high‐gain antenna using a single layer metamaterial (MTM) superstrate with a zero refractive index (n) is proposed. To enhance the magnitude and flatness property of the antenna gain at the same time, the effectively zero refractive index behavior of metamaterial superstrate is used, which gathers the wave emitted from the microstrip patch antenna and collimates it toward the normal direction of the antenna. Both the simulation and measurement results provide that the realized gain of the proposed antenna is increased by about 5 dB and the flatness of that gain is no more than 1.5 dB in the predicted frequency band, where the proposed MTM is designed to have a zero index of refraction. Consequently, the high and flat gain antenna can be easily obtained by using our MTM superstrate. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1973–1976, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24469