In some embodiments, an electromagnetic measurement system to perform radio frequency, RF, downlink testing of a device under test, DUT, in a chamber is provided. Exterior to the chamber is an emulator core configured to introduce an impairment in each of at least one transmit signal to produce at least one impaired signal for each of at least one emulated channel. Within the chamber, for each of the at least one emulated channel, an up-converter is configured to up-convert an impaired signal of the emulated channel to produce a radio frequency, RF, signal.