An attempt to increase the geometric size of the interrogation zone in UHF RFID systems with a phased array antenna is presented in this paper. The interrogation zone should be as large as possible. However, energy can be transferred to transponders only to a limited distance. The greatest flexibility in developing RFID applications and shaping the interrogation zone can be achieved using a phased array antenna. The perceived issues have been effectively dealt with and the solution has been proposed on the basis of an elaborated model. Conducted studies have been used to develop a software tool in the Mathcad environment. The research results are analyzed in detail for different system configurations and can be implemented in practical projects to be developed in cooperation with the industry.
 Jankowski-Mihułowicz P., Węglarski M., Determination of 3-dimentional interrogation zone in anticollision RFID systems with inductive coupling by using monte carlo method, Acta Physica Polonica A, vol. 121, no. 4, pp. 936-940 (2012).
 Dobkin, D., The RF in RFID, UHF RFID in Practice, Newnes (2012).
 Jankowski-Mihułowicz P., Kawalec D., Węglarski M., The Idea of Enhancing Directional Energy Radiation by a Phased Antenna Array in UHF RFID System, International Journal of Electronics and Telecommunications (2016), DOI: 10.1515/eletel-2016-0015.