Calibration, Synchronization and Sensitivity Topics in OTA Array Characterization

The many aspects of OTA array characterization, relative amplitude and phase control, linearity (including transferred linearity), etc., would be difficult enough in a connectorized world due to the mm-wave frequencies often needed and the size of the parameter space. In the over-the-air, and sometimes phsyically remote, test environment, things are even more complicated in terms of calibration (in a reflection correction sense as well as receiver and noise calibrations), synchronization (of possibly numerous sources and local LOs) and the senstivity of the measured parameters to environmental details, setup and positioning mechanics and challenging de-embedding problems. The structure of the subsystem under test can have a significant influence on the measurement issues and several common design approaches will be examined. This talk will explore some of the measurement considerations, sensitivity hot spots, and potential mitigation methods for this collection of structures to be analyzed.