Feedback circuit for noiseless damping of the Q of an MRI receiver coil antenna

Abstract

A feedback circuit for a magnetic resonance imaging (MRI) or spectroscopy device comprising a resonant circuit, including an MRI receiver antenna, for generating output voltages in response to nuclear magnetic resonance magnetization signals received by the antenna; an amplifier, coupled to the resonant circuit, for amplifying the output voltages; a resistive feedback path from an output of the amplifier to the resonant circuit, the feedback path carrying a first feedback current; and a capacitive current divider having a tap point to which the first feedback path is connected, for diverting a first portion of the feedback current away from the resonant circuit and for directing a second portion of the first feedback current to the resonant circuit. The Q value of the feedback circuit may be decreased without degrading the signal to noise ratio in order to obtain a sufficient bandwidth for receiving the nuclear magnetic resonance magnetization signals.

Dependencies are inferred from the claim text.