Circularly Polarized Dipole-like Antennas for Differentially-Fed IoT Applications

The implementation of Printed Circuit Board (PCB) antennas for the Internet of Thing (IoT) base station application is a co-design of the antenna size, shape, position, and board/ground layout. This paper investigates the radiation features of a typical PCB antenna combined with a dipole-type structure. A circularly polarized (CP) antenna for differential feeding is proposed and experimentally verified. By taking the advantage of the PCB antenna radiation and working principle of the dipole element, it is shown that CP radiation could be achieved for differential-fed signals. The proposed antennas demonstrate good radiation performance in terms of efficiency and bandwidth.