Analysis of rectifier operation with FSK modulated input signal

Abstract

This paper analyzes RF-DC conversion efficiency in a rectifier, which receives FSK modulated signal. To clarify the degradation of the RF-DC conversion efficiency, a bridge-type rectifier, which employs four diodes, a 180-degree hybrid, and matching circuits, is investigated due to its broadband operation. The simulation results show the degradation is mainly caused by mixing operations with various frequency signals on the diodes used. Compared with conversion efficiency of the rectifier at the CW input signal operation, it is found that the efficiency degrades one-third when a FSK modulated signal is received.