Four-Way Reconfigurable Repeater with U-Slot Microstrip Antennas for Outdoor IoT Applications

A four-way repeater with u-slot antennas whose RF signal flow can be switched electronically is proposed in this paper. Since the proposed repeater uses directional antennas managed by an SP4T RF switching circuit, it is naturally more efficient method than the omnidirectional alternatives in the literature. The repeater structure and the second layer of the antennas are produced by using a 3D printer. The core control unit of the proposed repeater is a microcontroller. The microcontroller manages the wireless communication module operating in 2.4 GHz ISM band and the SP4T RF switching circuit. The manufactured u-slot microstrip antennas of the repeater are measured with a vector network analyser and a radiation pattern measurement system. The results show that the proposed repeater and its u-slot microstrip antennas are very useful for the long distance IoT applications.