Investigation of Rectenna Array Configurations for Enhanced RF Power Harvesting

RF power harvesting enables controllable and simultaneous wireless power delivery to many RF devices. Devices built with this unique technology can be sealed, embedded within structures, or made mobile, thus eliminating additional service for a battery. A key component of this technology is the "rectenna," which is composed of antennas and rectifying circuitry to convert RF energy into dc power. Typically, multiple rectenna elements are used to generate the dc power for reliable device operation. This letter compares two different rectenna architectures for maximum RF-to-dc power conversion efficiency. A simple rectenna design example containing a 2 x 2 planar antenna array will be presented to demonstrate such RF power harvesting technology. The parameter, Rectenna Topology Indicator (RTI), is introduced for performance comparison.