Dual-Beam Rectenna Based on a Short Series-Coupled Patch Array

The multibeam multiport antenna is a promising solution for effectively harvesting wireless low-density power in a wide angle range. The traveling-wave series-fed patch array antenna without the requirement of additional beamforming circuits is a good option. However, its application is limited by its large length or low radiation efficiency. In this work, a periodic circuit model consisting of coupled resonators is proposed and analyzed for enhancing the radiation attenuation. A series-coupled patch array based on the model is then designed. It presents a much shorter configuration and could be well applied in a scenario where a tradeoff between size and gain exists. The dc combining method that accumulates currents of rectifying branches corresponding to multiple beams is adopted in the rectifier design. The rectenna exhibits an enhanced spatial or angular coverage with a simple configuration. In the measurement, the output dc power can be more than 0.5- 32 μW in an angle range of 90° in the H-plane and reach a maximum value of 1.1- 50.3 μW and a maximum efficiency of 19.5%-44.6% when the power density ranges from 0.05 to 1 μW/cm
²
at 2.45 GHz.