RF Rectifier Absolute Figure of Merit Based on Relative Comparison with Reference Rectifier

Although the performance of an RF rectifier is commonly evaluated using power conversion efficiency (PCE), that of various existing RF rectifiers cannot directly be compared. This is because PCEs are evaluated individually under different operating conditions. In this paper, an absolute figure of merit (FoM) using a reference rectifier circuit is proposed. The ideal factor, n-value, of a pn junction diode in a reference rectifier exhibiting the same PCE for operating conditions similar to that of a target rectifier under evaluation is taken as an FoM. It is demonstrated with a few examples that the proposed FoM is independent of the operation condition of the rectifier and can be used to evaluate various rectifiers objectively including those having a multistage configuration.