The results of technological investigations in the scope of inkjet-printed flexible RFID antennas dedicated to UHF transponders and also problems with the application of nanomaterials are reported in this paper. The design of the antenna electrical circuit and the parameters of the inkjet printing process were elaborated on the basis of the numerical model prepared in the Mentor Graphics HyperLynx 3D EM software. The project evaluation was performed by measuring electrical parameters of the structures printed with silver-based conductive inks. The obtained results confirm coincidence between the model and its implementation in the inkjet printing technology. Finally, the prepared antenna has been applied in an RFID transponder of UHF band and the functional tests are also reported in this paper.