An Efficient, Watt-Level Microwave Rectifier Using an Impedance Compression Network (ICN) With Applications in Outphasing Energy Recovery Systems

We present a transmission line based impedance compression network (ICN) for application in RF-to-dc conversion. We show that the ICN is able to significantly compress the undesired input impedance variation that occurs when there is a large variation of input power. We designed and measured an ICN for a 4 W, 4.6 GHz rectifier and show that the impedance is significantly compressed with the ICN. We then demonstrate the ICN in an outphasing system where we achieve up to a 37% improvement in efficiency at back-off power and an overall more efficient design over large input power variation.