Quiet-zone Profiling in a mmWave Spherical Anechoic Chamber: An Evaluation Approach

To ensure effective plane wave illumination of an antenna under test in an Anechoic Chamber (AC), a specific region known as the Quiet Zone (QZ) is typically specified. conventional ACs often employ the industry-standard free-space voltage standing wave method utilizing a horn antenna for the QZ characterization. However, to define the QZ in distinctive AC designs, it is essential to assess scanning methodologies that align with their unique working characterization mechanisms. In the mmWave spherical AC at Eindhoven University of Technology, a planar scanning methodology using an open-ended waveguide antenna has been explored to determine its applicability to the QZ assessment. An evaluation approach, incorporating spatial spread factor and probe pattern compensation, are first analyzed on a digital twin simulation and subsequently applied to practical measurements to study the chamber behavior. The agreement between the simulated and measured results validates the proposed planar scanning methodology and the evaluation approach for the QZ assessment.