Quasi-Isotropic Antenna-in-Package with a Shielded Core and Wide Circular Polarization Coverage

Given the dynamic nature of the Internet of Things (IoT) scenarios, peripheral devices’ radiation patterns must cover large areas to avoid disconnection in case of change of orientation relative to the base station. This broad coverage should be for both the power radiated as well as for the polarization of the electromagnetic wave, increasing the probabilities of a sturdy link between peripheral devices and the base stations. Current devices implement simple omnidirectional antennas that are linearly polarized and can be easily detuned due to the proximity of the electronics. This paper proposes an Antenna-in-Package design based on a microstrip patch volumetric array. The system consists of six circular patch antenna elements with perturbation segments. The patches work on the 2.4 GHz ISM band. Each element is placed on one face of a 3D hollow cube, and the internal walls are covered in metal, acting as a shielded core for the embedded electronics and ground for the patch elements. The design simultaneously demonstrates a 7 dB gain variation in 95% of the 3D sphere and a circular polarization coverage in 84%.