A RF transmit coil decoupling circuit in a parallel drive configuration comprises a power amplifier and an output matching network to shim the B.sub.1 field in response to inhomogeneities therein. The separate coil segments in a transmit array are effectively decoupled from each other despite inherent mutual inductance between coil segments by the decoupling circuit. The output matching network forms a high impedance block seen by the coil elements, while it provides a load line impedance at the output of the power amplifier. The transmission line transformer in the output matching network suppresses higher order harmonics for clearer RF wave forms. It also dampen the Q factor of the output matching network allowing stable operation with a series tuned coil element.