A Simple Technology for Designing Ultrawideband Rectifiers

The key difficulty for designing a wideband rectifier is to match the impedance of rectifying diodes at wide frequency range. In conventional works, the circuit topology and matching network are carefully designed to realize bandwidth extension. However, the operating bandwidth is concurrently limited by the matching network, while the size of the rectifier is usually enlarged. In this work, a novel feature of Schottky diode is found that its impedance is naturally not sensitive to frequency varying. Making full use of this feature, a simple matching network is employed, and the bandwidth can still be ultrawide. Furthermore, the proposed design method is effective to various diode models, thus can be applied to design rectifiers for different applications. For verification, a prototype is implemented. The measured results show that the rectifier can maintain a power conversion efficiency beyond 50% at frequencies ranging from 0.1 to 4 GHz (the relative bandwidth reaches 190%). The total size can be as small as
$1\times1$
cm2. The peak efficiency reaches up to 74.9%.