Design of A 2.45 GHz RFID Vortex Wave Antenna based on Characteristic Mode Theory

In this paper, a novel multimode vortex electromagnetic wave antenna for 2.45 GHz radio frequency identification (RFID) applications is proposed. Characteristic mode theory is used to analyze the characteristic currents of the array element column antenna so as to reduce the coupling between the array elements. The simulation results demonstrate that the return loss of a single array element and the whole array reach -26.14 dB and -25.85 dB, respectively, indicating excellent performance. Furthermore, both the antenna array element and the entire array are capable of functioning effectively within the 2.45 GHz band. The helical structure of each pattern is clearly discernible, indicating optimal performance characteristics.