Pascal Stang1, Marta Zanchi1, William Grissom1, Adam Kerr1, John Pauly1, Greig Scott1
Transmit arrays promise accelerated excitation, B1 shimming, and the potential for SAR and RF safety management. Yet good results demand high-fidelity RF playback in a challenging multi-channel environment. Parallel transmit RF systems must overcome a host of issues including mutual coupling, loading variations, RF amplifier non-linearity, ill-defined impedances, and memory effects. We have proposed Vector Iterative Predistortion and Cartesian Feedback as input predistortion methods to address PTx challenges. We now present our on-coil and in-line RF feedback sensors critical to these technologies, and discuss their relative capabilities in the context of PTx array control.