A line of RF vector signal generators (VSGs) and vector signal analyzers (VSAs) from National Instruments now includes two-channel, three-channel, and four-channel versions for multiple-input, multiple-output (MIMO) wireless testing. The NI PXIe-5663E 6.6-GHz two-, three- and four-channel RF VSA and NI PXIe-5673E 6.6-GHz two-, three- and four-channel RF VSG versions are based on PXI Express. They incorporate a shared local oscillator (LO) architecture for true phase coherency between each RF port. These instruments complete an integrated software-defined, phase-coherent measurement system for MIMO, direction-finding (DF), radar testing, and beam-forming applications that require channel-to-channel RF port synchronization.