High-Efficient Slot-Coupled Superstrate Antenna for 60GHz WLAN Applications

A high-efficient and high-gain aperture coupled patch antenna with superstrate at 60 GHz is studied and presented. It is noted that adding a superstrate with a specific size will induce a significant effect on antenna gain and radiation patterns. The maximum measured gain of a single antenna with superstrate is 14.6 dBi, which is higher than that of a classical 2x2 array. It is found that the measured gain of a single antenna with superstrate increases nearly 9 dB at 60 GHz over its basic patch antenna. This superstrate antenna gives a very high estimated efficiency of 76%. The 2:1 measured VSWR bandwidth with superstrate is 6.8%. The radiation patterns are found to be broadside all over the frequency band. A 2 x 2 aperture coupled patch antenna arrays with superstrate is also studied. The corresponding maximum measured gain is 16 dBi with an efficiency of 63%, which is 4 dB higher than that of a classical 2 x 2 array at 60 GHz. The 2:1 measured VSWR bandwidth is 6.7%. The radiation patterns are found to be broadside all over the frequency band with a very low back radiation level. Hence aperture coupled superstrate antenna technology is a good candidate for high efficient high gain application at 60 GHz.