Pascal P. Stang1, Marta Gaia Zanchi1, Adam Kerr1, John Mark Pauly1, Greig C. Scott1
Transmit coil arrays are subject to mutual coupling and loading variations, while RF power amplifiers exhibit non-linearity, ill-defined output impedances, and memory effects. We examine and successfully demonstrate Frequency-Offset Cartesian Feedback (FOCF) as a method to address these challenges, showing improved RF amplifier linearity, output impedance manipulation, and active coil decoupling in MR images. Corrections are performed using only an in-line vector coupler at the RF amplifier, with no on-coil sensor needed. Tuning for active decoupling and stability sensitivities are discussed.