Correlation Technologies for OTA Testing of Mobile Devices: Power-Density Measurement

In this paper, we introduce new correlation technologies for measuring Power-Density of mobile devices in the framework of Over The Air (OTA) testing. The correlation technologies use convolutional signal processing algorithms. Measurements obtained using minimally invasive ElectroOptical (EO) probes are compared to those from classical near-field and far-field measurement solutions demonstrating excellent accuracy for applications at mmWave frequencies. Influence of separation distance between the Device Under Test (DUT) and the probing system (PS) on the near-field spatial correlation functions is studied. Broadband measurement results are successfully compared to full-wave 3D EM solvers in time and frequency domains. Perspectives for optically synchronized inteferometric-correlation technologies are drawn for accurate measurements, in noisy environments, of stochastic EM fields using power-spectra and energy-spectra metrics.