Recent work has shown parallel RF transmit (pTX) chains with increasing channel counts and complexity. At the same time, methods of controlling and monitoring pTX chains must improve, especially when faced with nonlinearities in the RFPAs. However, characterizing multichannel nonlinear RF systems is a daunting task for standard laboratory instruments. Here we present a coupled network analyzer (CNA) containing 16 independent RF transceivers which are used simultaneously by a digital acquisition unit (DAQ). Additional DAQ channels can be used for monitoring power consumption or temperature. The system may also be interfaced with an MRI scanner to function as a pTX synthesizer.