The proposed design is based on several substrate stacked directly on each other, resulting in a very small footprint of the entire geometry.
This configuration was demonstrated using two types of feeding techniques, showing the outstanding flexibility of the concept and suggesting its easy integration into mil-limeter-wave front-ends. The building elements and the 4  4 antenna array are analyzed, designed and measured. This offers the conception of a high gain antenna (19 dBi was reached) with compact size and minimal footprint. The measured results of S-parameters show a good bandwidth, a gain of 18 dBi, which are in very good agreement with the simulated results. The pro- totyped 4  4 array has a size of 28  24  2.4 mm  (including the distributed network feeding). Such a very small footprint leads to a far field around 16 cm at 60 GHz that allows a very close scanning unlike standard horn antenna.