Ultra-compact 4-sector antenna system based on modified Van Atta array

This paper presents the design and experimental characterization of an ultra compact four sector antenna system operating in the 5 GHz WiFi band. The design is based on the use of a modified Van Atta retro-directive array [1] where very closely spaced elements are placed in the near field of the feeding sources. More than 10 dBi directivity is obtained for each sector with a prototype realized on a multilayer PCB substrate. The antenna solution fits into a cylindrical volume of 30 mm of diameter × 13 mm high over a ground plane of 25 cm × 25 cm size and is well suited for integration in WiFi embedded home devices such as Set Top Boxes or Home Gateways.