Over-the-Air Characterization Of mm-Wave On-Chip Antennas and Tx Modules, Concept and Calibration

In this paper, the enabling of the standard configuration of the mm-Wave VNA to perform Over-The-Air antenna characterization is presented. The measurement setup proposed allows to fully characterizing the different type of on-chip antennas thank the vector power calibration and the phase calibration. In fact, using the power calibration, the setup allows measuring the absolute value of the power at the calibration reference planes directly using the VNA’s receivers. Adding the phase calibration to the calibration procedure enables the measurement setup to provide two phase-coherent sources (at port1 and port2) allowing the characterization of a combining active fed on-chip antenna. Measurements of a stand-alone antenna from 220 to 500 GHz and of a combining active fed on-chip antenna among the frequency (from 130 to 155 GHz) and among the relative phase variation (from 0 to 70 degrees) are presented. The measurement results, in the first case, show a very good agreement with simulation while, in the second case, show the capability of the setup to control the relative phase of its two ports.