• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.57-63
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• 2019

S-parameters were used to analyze the effect of the circuit according to the height of the EMI shield layers. Among the S-parameters, S11, S21, S22, and S31 were used as factors for determining the effect on the circuit function. Simulations were performed using shields made of Graphite and Ferrite, and the frequencies were run from 100 MHz to 1 GHz. As the height of the shield was increased, the value of S21 was getting closer to 0 dB. In addition, the SE value was confirmed to improve the shielding performance according to the thickness of the insulating layer only in a specific frequency band. Based on 800um with thickest silicon dioxide thickness, the FG structure averaged -1 dB in narrow frequency bands between 100 MHz and 300 MHz, showing better efficiency than GF with an average of -2 dB. Although GF structures do not show high efficiency, they exhibit average performance of -3 dB in frequency bands between 100 MHz and 1 GHz rather than FG structures that sway over a wide range. In other words, FG and GF structures have trade-off structures. Therefore, it should be noted that the appropriate structure is selected for use.