EMR Field Distribution Analysis of Crystal Oscillator on PCB

Abstract

On PCB (Printed Circuit Board), the crystal oscillator circuit is the main source of electromagnetic radiation (EMR) interference. The simulation and analysis of its EMR characteristics is one of the key tasks of PCB EMC (Electro Magnetic Compatibility) design. In this paper, the simulation models are established by HFSS, and the EMR characteristics of crystal oscillator in different cases are simulated and analyzed. And the relationships between the electric field intensity and frequency are got. The simulation result shows that the area of the larger field intensity is concentrated in the middle part of the two pipe feet. When the shell is grounded, the field intensity around the shell is almost 0. When the PCB wireway is connected, the field intensity changes to concentrate at the end of the wireway. When the grounding capacitance is connected, the maximum field intensity decreases by 77.02%. The conclusion of this research provides an important theoretical basis for improving the EMC design of PCB.