A New Rectenna Using Beamwidth-Enhanced Antenna Array for RF Power Harvesting Applications

This letter presents a new rectenna using beamwidth-enhanced antenna array for RF power harvesting applications. Based on an example of a 1 × 4 patch antenna array, the beamwidth-enhancement method is demonstrated. By maximizing the power transmission efficiency between the 1 × 4 antenna array and two auxiliary antennas, the optimal excitation distribution that leads to an enhanced beamwidth can be determined. In comparison to the same antenna array fed by the uniform amplitude and phase, the beamwidth of the designed antenna array at the H-plane is about two times wider. A high-efficiency rectifier is designed to convert the harvested RF power into dc power and is then combined with the 1 × 4 antenna array to form the proposed beamwidth-enhanced rectenna. Measurement results show that the rectenna's efficiency is more than 50% when the wave incident angle is between -38° and 35° at the H-plane under the power density of 1276 μW/cm
²
.