Bandwidth improvements of 60GHz micromachining patch antenna using gap coupled U — Microstrip feeder

In this paper, a 60 GHz antenna is designed for WLAN applications. This antenna is built-up on a Silicon membrane with an upper BCB (Benzo Cyclobuten dielectric) thin film deposit and excited with a U or T-shape microstrip feeder via a dielectric gap. The coupling of the patch antenna with its feeder allows to improving the frequency bandwidth and radiation efficiency of a simple patch without increasing the realisation complexity. Furthermore, the realisation of this antenna is compatible with the IEEE 802.15.3C standard. For antenna efficiency equalling 90%, the obtained relative bandwidths occupy 13.3 % of 60 GHz for T-shape antenna and 12.3 % for U-shape antenna, i.e., respectively 2 and 1.8 times greater than for a simple patch. With same performance, the U-shape antenna is smaller than the T-shape ones. Consequently, this antenna is more compact and could be suitably used for designing beamforming array.