Florian Wiesinger1, Eric W. Fiveland2,
Albert J. Byun2, Pekka Sipilae1, Christopher J. Hardy2
1Imaging Technologies, GE Global
Research, Munich, Germany; 2MRI Laboratory, GE Global Research,
Niskayuna, NY, United States
Radiation
damping (RD) describes a second-order effect where the signal-induced current
in the receiver coils acts back onto the primary spin system. According to
Lenzs law, the RD acts in a way to oppose its original cause. In that sense RD can be understood as a
self-regulating flip-back pulse. Recently, RD feedback loops have been
introduced into the RF signal path to boost the natural RD effect. While previous RD circuits were limited in
terms of feedback gain, here we present a new feedback circuit, which
principally circumvents this problem via time separation of RD receive and
transmit.
Keywords