Far field prediction of a PCB using simulation and validation

The modern automotive industry shows evident rise in use of electronic components leading to increase in chances of electromagnetic disturbance due to electromagnetic radiations. AIS 004 standards give the way of measurement as well as acceptable field strength limits. The test setup for this far-field measurement is complex and it requires resources like semi-anechoic chamber and controlled environment. Also, it is difficult to predict source of emission through this experiment. Ultimately the manufacturer left with no other option than to adopt trial and error method to find the source of electromagnetic disturbance and meet the requirements as per standard. However, simulation based technique can be used to simulate far field emission and detect the source, and pattern of radiation. A case study demonstrating the methodology to predict far field emission is carried out with a printed circuit board (PCB) consisting of a DC-DC convertor along with a crystal oscillator. A physical prototype of PCB was developed and tested in semi-anechoic chamber for far field emissions as per AIS-004. The same PCB is then modelled in E-CAD format. The ECAD data is further imported in Altair FEKO and used for simulating far field emission. The experimental test setup was accurately captured in simulation. Further, simulation results in terms of electric field emission in far field region were obtained. The methodology developed will reduce the product development time and provide cost effective solution. Also, the source of emission can be detected at the early design stage itself. Improvements can be made with design iterations and it can be ensured that the developed prototype meets the requirement.