  In this work, we show the design and validation of a testbed for over-the-air
testing of millimetre waves equipments. We have extended the frequency
capabilities of a baseband channel emulator which is capable of emulating
non-stationary channels, to higher frequencies. To assure that the propagation
between devices-under-test and the RF-frontend of the emulator is only a
line-of-sight link, we have isolated the devices-under-test in two anechoic
chambers. We characterize the testbed at 57 GHz by means of frequency sweeps
for two artificial cases: when the emulator is replicating a one-tap channel
and a two-tap channel. Finally we demonstrate the system functionality through
reproduction of channels which were acquired during a vehicular millimetre wave
measurement campaign conducted in Vienna in 2018.
