Compact rectenna based on a fractal geometry with a high conversion energy efficiency per area

This work presents the design of a rectenna topology by using a compact microstrip patch antenna based on a fractal model and with the rectifier circuit integrated into the same physical structure. This configuration presents a very reduced circuit area, which makes the proposed rectenna circuit suitable for harvesting and wireless power transfer applications where the size is critical. The proposed compact rectenna, implemented on a low-cost FR-4 substrate, can harvest RF power from 2.45 GHz (ISM band) with a efficiency of ∼62% when the input power harvested by the rectenna is +2 dBm. The suggested rectenna has been manufactured and experimentally characterised, showing a good agreement with the expected simulated results.