Circularly polarized antenna in 3d printing technology to feed a wearable fully-integrated WiFi-RFID reader for biomedical applications

In this work, a compact, low-profile, portable RFID reader suitable for medical applications has been proposed and its antenna designed, realized and tested. Specifically, a circularly polarized UHF RFID reader antenna conformal to a dielectrically controlled plastic support is proposed. The radiating element has been realized through a circular array of four inverted-F monopoles, where the array elements are excited with a 90-degree phase offset (sequential rotation feeding technique) through a microstrip feeding network. To allow for a friendly prototype realization, the antenna structure is thought to be shaped on adhesive copper and the dielectric support to be 3D-printed in Poly-Lactic Acid (PLA), opportunely selected due to interesting low losses properties. The very compact antenna (60mm x 60mm x 6.5mm), suitable for the desired portable Reader, has been characterized in terms of reflection coefficient, port isolation and radiation patterns.