Electronically Pattern Reconfigurable Antenna for IoT Applications

In this paper, an electronically pattern reconfigurable antenna for Internet of Things (IoT) applications is presented. The antenna consists of 4 wire-patches sharing the same ground plane. This radiating element can switch between four end-fire radiation states in less than 5 us and achieves a 290 MHz frequency bandwidth from 2.25 to 2.54 GHz. The results show that this antenna can realize a peak gain of 3.9 dBi at 2.44 GHz and a front-to-back ratio greater than 6.5 dB. A single low-power, low-insertion loss SP4T switch enables the radiation pattern steering. This approach avoids the use of multiple electronic components in the reconfiguration mechanism, thus accommodating the IoT microcontroller's limited resource constraints. The antenna structure is compact and printed on two cost-effective FR-4 printed circuit boards (PCBs). Thanks to its high performance, small size, low cost, and low-power characteristics, the proposed structure is suitable for IoT applications.