Design and Implementation of a Wireless Power Transfer (WPT) System for Autonomous Power Supply to Remote Weather Stations Using Yagi Antennas at 2.45 GHz

This article presents the design and implementation of a long-distance Wireless Power Transfer (WPT) system operating in the 2.45 GHz ISM band, which allows continuous or intermittent power transmission via highly directional microwave links. The transmitter subsystem consists of an ADF4351 wideband frequency synthesizer tuned to 2.45 GHz, a medium-gain amplifier (SPF5189Z), and an RF2126 power amplifier, radiating through a high-gain Yagi antenna optimized in 4nec2, with the aim of transmitting sufficient and permitted power up to a maximum of 1 km for the constant or intermittent power supply of low-power electronic devices. At the receiving end, a tuned Yagi antenna captures the RF energy and conducts it to a rectenna composed of Schottky diodes, low-pass filters, and impedance coupling. The rectified energy is stored in supercapacitors and regulated by ultra-low start-up DC-DC converters (LTC3108) to supply power to a modern embedded weather system with a maximum consumption of 15mA. This architecture demonstrates WPT's technical feasibility and sustainability in the far field for low-power applications in remote areas, reducing dependence on batteries and solar panels, minimizing maintenance, and increasing operational reliability in hostile or isolated environments.