A low-profile dual-band antenna using fractal-based wideband metasurface with stable radiation pattern

A low-profile dual-band metasurface antenna is demonstrated for 4G LTE and 5G Sub-6GHz applications. Based on the characteristic mode analysis, a wideband metasurface with stable radiation pattern is proposed by introducing Minkowski fractal structure in the edge patches and scaling the corner patches. The metasurface is operating in Sub-6GHz band and excited by a Vivaldi bowtie slot antenna, which also serves as the radiator in LTE band. To validate the concept, a prototype with an overall size of 1.05 lambda(0) x 1.05 lambda(0) x 0.045 lambda(0) (lambda(0) is the free-space wavelength at 2.3 GHz) is fabricated. The experiment results show that the -10 dB impedance bandwidths in two bands are 1.7-2.78 (48.2%) and 3.2-5.01 GHz (44.1%), respectively. Moreover, broadside radiation performances in two bands are obtained.