Probing Millimeter-Wave Antennas and Arrays in their Reactive Near-Field

A test concept is presented for millimeter-wave antennas and arrays using metallic probes inserted in the reactive near-field of the single radiating element. Several probe techniques are disclosed where the disturbance of the antenna radiator feed impedance, typically encountered due to the insertion of the metallic probe into the reactive near-field of the radiator, is negligible. Simulations and experiments show the stable feed impedance and a transmission magnitude from the antenna feed to the probe port of about -20 dB. At the same probe port, the unwanted coupling from neighboring radiator elements is smaller by 10 dB. The technique is applied to patch antennas, planar dipole antennas, and to a class of package-embedded antennas. The advantages of the proposed concept for the production test of millimeter-wave transceiver-integrated antenna array modules are discussed.