| 摘要 |
A mobile terminal having an improved electromagnetic shielding function is provided to effectively remove EMI(Electro Magnetic Interference) noise components due to suitably varying the cutoff frequency characteristic of an EMI filter by sensing a data rate transmitted through a signal line or a change in temperature. A mobile terminal having an improved electromagnetic shielding function comprises an EMI filter(100), a varicap diode, and a control part(300). The control part(300) checks cutoff frequency characteristic variation factors, such as a data rate transmitted through a signal line, temperature, etc. Then the control part(300) compares the checked data with the data stored in a compensation value database. As a result of comparison, if it is required that the cutoff frequency characteristic of the EMI filter(100) should be changed, the control part(300) outputs a PDM signal for an associated compensation value stored in the compensation value database. The PDM signal passes through a 2-pole RC filter. The signal, outputted through the RC filter, varies the bias voltage of the varicap diode. The cutoff frequency characteristic of the EMI filter(100) is changed as a variation in the bias voltage of the varicap diode varies the capacitor(C) of the EMI filter(100).
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