Near-Field Validation of Dipole-Moment Model Extracted From GTEM Cell Measurements and Application to a Real Application Processor

Source models for radiated emissions of test integrated circuits are extracted from measurements using a gigahertz transverse electromagnetic cell. The source model consists of magnitudes and relative phases of three dipole moments. The extracted source models are then validated by the measurements of a near-field scan. The measured near fields are quite similar with those calculated from extracted dipole moments when the target source size is small as compared to the observation distance. The effects and valid ranges of the proposed modeling method are quantitatively investigated in calculations and simulations. The proposed modeling and validation procedures are also applied to the radiated emissions of an application processor (AP) in a real operating mobile product. The extracted dipole models for the real AP show reasonable accuracy. The proposed source modeling approach should be helpful for investigating and resolving system-level radio frequency interference problems.