Multilayer Dielectric Resonator Antenna Transmitarray for Near-Field and Far-Field Fixed Rfid Reader

Abstract

Abstract-A design of multilayer dielectric resonator antenna transmitarray for fixed radio frequency identification (RFID) reader applications is presented at 5.8 GHz. Three layers square dielectric resonator antenna (DRA) elements are mounted on dielectric substrate and used as a unit cell in the transmitarray. 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. The right-hand circular polarization level is lower than −31 dB at the designed frequency with SLL of −22 dB. A design of 9 × 9 near-field focused DRA transmitarray for fixed RFID at 5.8 GHz is investigated. The properties of the near field-focused transmitarray are compared with that of the far field transmitarray designed at the same operating frequency.

Near-Field-Focused Microwave Antennas: Near-field shaping and implementation

“…Fresnel zone plate lens antennas [45]- [46], transmitarrays [47] and reflectarrays [50]- [52] have also been considered to implement NFF planar lens antennas, which can be considered as devices that are able to shape the phase-front of the electromagnetic field radiated by a conventional feed antenna. All of them are suggested to avoid the complexity and losses introduced by the feeding network of electrically large NFF microstrip arrays.…”

“…A number of NFF arrays have been proposed for fixed RFID readers: planar arrays [41], [49], [53], [54], and reflectarrays [52] at 2.4 GHz; circular arrays [26], dielectric resonator antenna arrays [55]- [56] and dielectric resonator transmitarrays [47], for RFID readers at 5.8 GHz; dual-band NFF reflectarrays operating at 915 MHz and 2.4 GHz [50], [51].…”

Technologies for Near-Field Focused Microwave Antennas

“…If the focal length reduces to 4 cm, then the spot size diminishes to 1.4 cm, although the side lobe level is slightly higher in this case. In [49], a 9 × 9 NFF transmitarray using CP dielectric resonator antennas as radiating elements has been designed and compared with the FF-focused version of the same transmitarray. The phase control of the radiating elements is implemented by changing the side length of the square dielectric resonators.…”

Ka‐band multi‐focus and pattern manipulation in near‐field based on three‐dimensional printed transmit‐array antenna

“…The presentation of air-fed antennas, e.g. Fresnel zone plate lens antennas [13], transmit arrays (TAs) [14,15] and reflect arrays [16], which can be considered as devices that are able to shape the phase-front of the electromagnetic field radiated by a conventional feed antenna, can mitigate these issues and act as good alternatives for NFF antennas.…”