Time efficient method for automated antenna design for wireless energy harvesting

The rectifier circuit in a rectenna (rectifying antenna) is analyzed employing a fast, efficient time-marching algorithm. The thus found complex input impedance dictates the antenna design. To maximize RF-to-DC conversion efficiency we do not want to employ an impedance matching and filtering network. Instead, we require the input impedance of the antenna to be equal to the complex conjugate value of the input impedance of the rectifier circuit. One antenna type feasible of supplying the required complex input impedance is the wire folded dipole array antenna. For this antenna type, an efficient, analytic model has been developed. The fast calculation times when implemented in software allow for an automated antenna design employing a Genetic Algorithm optimization. Thus, antenna designs can be generated within minutes employing standard office computing equipment. The design of a complete rectenna can be accomplished within hours. The direct complex conjugate matching ensures that the design is power-efficient and physically compact.