A flag-shaped printed dipole array for ambient scanning

The design and performances of a low-cost light-weight two-element array in printed circuit technology is presented. The array far-field is designed in such a way to be suitably adopted by “smart” RFID readers, which do not limit themselves to collect IDs only. On the contrary they are capable to interact with tagged objects, even hidden, widely distributed in physical ambient, and to exchange data with them. For this purpose the array implements the RADAR-Monopulse technology coupled with beam steering capabilities which allow the reader to track the signal direction of a specific tag, located in close proximity to others, and selectively interact with it. The design is developed to operate in the 2.45-GHz band but it is frequency-scalable: the higher the operating frequency the closer can be the tags to be successfully selected or detected.