Digitally Synthesized Antenna Test Bench for Next Generation Phased Array Systems

With the increasing digitalization of radar new test benches must be employed for antenna measurements. The conventional antenna testing approach cannot be applied to fully digital phased array antenna systems. This paper explores the new challenges regarding the testing of a digital array radar which cannot be performed using a legacy antenna test bench operating in the RF domain only. The measurement setup is based on a couple of generator/I-Q analyzer that have to be locked to the system under test during the measurement in order to ensure phase coherence of the transmitting and receiving pulse. This paper addresses a strategy to generate an auxiliary reference in the RF domain to compensate the phase variation over the measurement time. The proposed test bench can be easily reconfigured for a radar test bench where the main challenges are not seen in terms of phase stability over long measurements, but in many other complex scenarios such as pulse to pulse stability, waveforms agility, jammer interference.