Test system and test method

A test system for testing an array antenna under test with at least two antenna under test with at least two antenna elements, the test system comprising:

• a signal generator that generates a test signal,
• a signal splitter that splits the test signal into a plurality of antenna source signals for the single antenna elements,
• a plurality of vector multipliers coupled to the signal splitter, the plurality of vector multipliers including a vector multiplier for each one of the antenna source signals, wherein the vector multipliers each adjust the amplitude and/or phase of the respective antenna source signal according to predetermined adjustment parameters and wherein output ports of the vector multipliers are connected to respective ones of the antenna elements,
• a signal coupler for each of the vector multipliers that couples out part of each adjusted antenna source signal, and
• a controller that corrects the adjustment parameters for the single vector multipliers based on the coupled out part of the respective adjusted antenna source signals and provides the corrected adjustment parameters to the respective ones of the vector multipliers,
• a phase discriminator receiver that receives the coupled out parts of the adjusted antenna source signals and determines the phase and/or amplitude of the respective adjusted antenna source signals, wherein the controller corrects the adjustment parameters based on the respective determined phases and/or amplitudes, and
• a multiplexer that multiplexes the coupled out parts of the respective adjusted antenna source signals, wherein the phase discriminator comprises a de-multiplexer that de-multiplexes the coupled out parts of the respective adjusted antenna source signals prior to determining the phases and/or amplitude of the respective adjusted antenna source signals.