B10. Multilayer dielectric resonator antenna transmitarray for near-field and far-field fixed RFID reader

A design of multilayer dielectric resonator antenna transmitarray for fixed RFID reader applications is presented at 5.8 GHz. Three layered square DRA element mounted on dielectric substrate is used as a unit cell. The dimensions of the unit cell and the number of layers are optimized to give phase distribution of the transmission coefficient from 0 to 2π. A circularly polarized 9×9 square DRA transmitarray is designed at 5.8 GHz for far-field RFID applications. The transmitarray produces maximum gain of 20.2 dB with 1 dB bandwidth of 1.4 GHz. A design of 9×9 near-field focused DRA transmitarray for fixed RFID at 5.8 GHz is investigated. The properties of the NF-focused transmitarray are compared with the far field transmitarray designed at the same operating frequency. The 3-dB spot area radius of the NF-focused transmitarray aperture is 7.84 cm at the focal plane z =Ro=40 cm with SLL of -17.6 dB.