High Performance Dual Polarized Near-Field Probe at V-Band for Spherical Near-Field Measurements

V-band (50-75GHz) applications such as 5G and myriad others are the catalyst for high performance near-field antenna measurement systems. For Spherical Near-Field (SNF), the traditional approaches at millimeter wave frequencies collect two full spheres of data in the near-field where each sphere samples one of two linear and orthogonal fields of the antenna under test (AUT). These two orthogonal polarizations are traditionally achieved through mechanical rotation of a single polarized probe. To improve measurement time and accuracy, MVG has developed a dual polarized V -band probe. This probe has been integrated in a millimeter wave SNF system (u-Lab) and is connected to two simultaneously sampled parallel receiver channels. This approach only requires one sphere to be measured and it ensures the two polarization components are sampled at the same point in space and time. The SNF probe design proposed in this paper is based on an axially corrugated aperture. The probe includes a compact integrated ortho-modal transducer (OMT) and the ports are WR-15 waveguide. This paper will present the design requirement, design details, and measured performances of the proposed dual polarized SNF probe.