Gain Enhancement of a Dual-Band Antenna with the FSS

A dual-band directional antenna for Industrial, Scientific, and Medical (ISM) band application is proposed in this article. The consists of two layers substrates. first layer contains the square loop loading with a meander stub to realize dual band. second frequency selective surface (FSS) structure, which periodic array loops. phase shift from FSS reflection distance between are optimized field superposition, could achieve gain enhancement bandwidth improvement at operating bands, simultaneously. measured results indicate that within 2.3–2.62 GHz range 4.9–6.45 range, |S11| less than ?10 dB. dB impedance 13% 27%, respectively. 6.8 2.45 9.0 5.8 GHz. Meanwhile, over 8.5 5.0 6.0 working covers all bands WLAN. design has good prospect future.