An efficient, fully-planar cavity backed module for smart array antennas

We present a cavity-backed patch antenna with enhanced bandwidth and good efficiency which is assembled in a multilayer fully planar structure. The single element represents a basic block that can be replicated in a modular configuration to design array antennas implementing beam scanning or more general "smart" functionalities. To do that, each element has to be provided by a phase shifter that can be directly integrated on the layer hosting the beamforming network. For this reason, particular care was taken to minimize the space occupied on this layer by the feeding and matching network, so that most of the space of the unit cell is left free. The antenna was designed using a commercial, method of moments (MoM) based software. Results are shown for a single element and for a 2x2 array; a prototype is under construction.