High-Resolution Probes for Near-Field Measurements of Reflectarray Antennas

This letter proposes three different near-field-measurement probes in order to characterize individual patches on the surface of reflectarray antennas, both in phase and amplitude. The first realized structure is a dielectrically filled waveguide probe, the second is a probe ending in a dipole structure, and the third is a substrate-integrated waveguide probe. Requirements for near-field probes in this application are high resolution and reduced influence of the probe on the examined structure. The ability of the presented probes has been investigated by simulations and validated with measurements at a frequency of 35 GHz at reflectarray structures, placing the probes a few millimeters above the antenna surface.