Quiet Zone Verification of Plane Wave Synthesizer Using Polar Near-Field Scanner

5G active antenna system base stations operating in frequencies below 7.125 GHz (FR1) need to be tested using a cost-effective OTA measurement solution since traditional farfield antenna ranges are too large. Plane wave synthesizer (PWS) allows testing with far-field conditions at the near-field distance with the minimum system dimensions. Uniformity of the synthesized plane wave field in the quiet zone (QZ) is a key performance parameter of PWS. QZ verification setup using a polar near-field scanner and a vector network analyzer is presented with description of the main hardware components, instrument settings and correction techniques for raw measurement data. Various field uniformity metrics are defined and calculated for one measurement example. Measurement repeatability is also verified to evaluate stochastic errors in the verification.