Dynamically Reconfigurable Broadband SP3T Switch Powered by WPT for Antenna Switching Applications

Abstract

In this work, a broadband single pole triple throw (SP3T) switch that operates between a frequency range of 0.02 – 6 GHz is reconfigured by means of wireless power transfer (WPT) through an energy harvesting (EH) circuit. The WPT is achieved by designing three rectennas working at 2.3 GHz, 2.45 GHz, and 2.6 GHz. Each rectenna consists of a low-power RF rectifier circuit associated with a distinct antenna element and a commercially available e-peas AEM30940 power management unit (PMU) that is able to provide an output of 1.8 V – 4.1 V with cold start-up from 380 mV and 3 µW input power. The PMU also consists of a storage capacitor where the energy from the low power received signal is stored. The three input pins of the SP3T switch require a driving voltage of 1.8 V to actuate its RF port. This voltage is provided by the designed rectennas through the PMU, and we can actuate the switch with a very low power (3 µW) received signal. The rectennas are designed to provide the 380 mV between −12 dBm to −10 dBm received power with a conversion efficiency of approx. 40 %for each rectenna. The proposed method to wirelessly enable the SP3T switch with a low-power RF signal can provide a breakthrough to reconfigure microwave devices and antennas for a broad range of applications, and also paves the way not only for the generation of clean energy, but also for its use as an alternative to batteries.