Octagonal Patch Tag Antenna and 3 × 3 Array Locator for DoA Applications

In this paper, a new circular polarized microstrip antenna with an octagonal patch for Bluetooth Low Energy (BLE) application is presented. In the antenna configuration, a two-layer stack-up between the patch and ground plane has been exploited to simplify the routing of the grounded coplanar waveguides (GCW) on the back of the antenna. This configuration ensures minimal crosstalk in the 3 × 3 array arrangement. A circular via fence has been used to emulate the behavior of a coaxial cable, effectively mitigating the inductive effects of the probe. The comparison between measurements and simulations has been performed with good agreement between measured and simulated radiation patterns.