Dual band circularly polarized truncated patch antenna for RFID reader and WiMAX applications

摘要

Novel asymmetric cross slotted truncated patch antenna is proposed for circular polarized radiation for UHF RFID reader and WiMAX applications. Proximity feed technique is adopted for the reduction of spurious radiation and improvement of bandwidth The antenna consists of two microstrip patches with asymmetric cross slots fed with a microstrip line in the same plane of the patches. An arrow shaped cross slot on the ground plane is employed for coupling power to the radiating patches. The effects of truncating corners on the patches are investigated. Truncation offers better bandwidth and reduction in VSWR with circularly polarized radiation pattern. The circular polarization is an essential requirement as the RFID reader and performs interrogation of randomly oriented RFID tags.