Efficient Analysis and Prediction Method of Radiated Emission for EMC Compliance

Abstract

In the last several decades, advanced electronic technology systems have continued to develop and, accordingly the complexity of such electronic system has increased. A complex electronic systems can cause electromagnetic compatibility (EMC) problems. Integrated circuits (ICs) in the radio frequency (RF) and digital integrated electronic devices are major electromagnetic noise sources, causing electromagnetic interference (EMI) problems. The radiated emission (RE) from ICs in the intra-system can cause RF interference (RFI) problems. Also, the far-field radiation induced from the component, such as ICs, printed circuit boards (PCBs) and cables, in the electronic system can violate standard EMI regulations. Therefore, the prediction of RE based on simulation is helpful for the product development process in terms of both cost and time. In this thesis, efficient approaches of extracting equivalent dipole source model for an operating IC is proposed. By using equivalent dipole source model, near-field radiated from an IC can be calculated and simulation-based intra-system RFI analysis is possible with implementation equivalent source and product structure in the simulation tool. Also, an efficient simulation-based quantitative analysis of the electromagnetic coupling between a component in electronic systems and an antenna is proposed to predict the RE and radiated immunity (RI) under the standard setup. In Chapter II, two approaches of the equivalent source modeling method for efficient RE analysis are investigated. First, the efficient method of extraction single point equivalent dipole source model for an operating IC with gigahertz transverse electromagnetic (GTEM) cell is newly proposed. By increasing the number of GTEM cell measurements, the method proposed in previous research has been improved to extract an equivalent source model that includes not only the magnitude but also the relative phase of each dipole-moment. The validation process of the extracted equivalent source is conducted by measuring the near-field radiated from the target radiation source. The proposed equivalent source modeling method is applied to the near-field analysis of an application processor (AP) in a real operating mobile product. Next, the accuracy investigation of equivalent dipole arrays extracted with near-field scan data is conducted by considering the several factors affecting extracting and evaluating the equivalent dipole array source model. Simple guidelines are also suggested for extracting equivalent dipole arrays for a given source with near-field scan data by considering three that can affect accuracy in the step for extracting equivalent source: scanning height, source spacing, and scanning gap. The suggested simple guidelines and the effects of the evaluation height on accuracy of reconstructed fields are demonstrated with simple trace structure simulation and the test IC measurement in the presence of shielding or dielectric structures. In Chapter III, the efficient prediction method of electromagnetic coupling between a specific component and an antenna is proposed by applying the decomposition method based on the reciprocity theorem and Huygens’s principle. The decomposition method along with the extraction of an S-parameter block is extended to handle the dominant transverse electric (TE) mode in a waveguide antenna. The proposed method removes the difficulty and uncertainty in the modeling process of a commercial waveguide antenna. While applying the decomposition method, Huygens’s principle is additionally applied to further reduce the full-wave simulation time of a large empty space. Moreover, a split domain approach for coaxial cable is proposed to split the device under test (DUT) into multiple segments for efficiently analyzing structures including coaxial cable. The proposed time-efficient techniques can realize the full-wave computation of electromagnetic coupling of real complicated systems and commercial antennas.