| 摘要 |
PURPOSE: A device and a method for preventing high field interference of a TV are provided to turn off a wideband amplifier when high field RF(Radio Frequency) signals are inputted to the wideband amplifier, so as to prevent the interference between adjacent channel signals. CONSTITUTION: A wideband amplifier(100) amplifies inputted RF signals to wideband signals. A distributer(110) distributes the signals amplified in the wideband amplifier(100). First and second tuners(120,160) respectively receive the distributed signals to select channel signals according to the selection of main and sub channels by a user, and perform AGC(Automatic Gain Control) of an internal amplifier according to electric field sizes of each selected signal, to output an AGC voltage. First and second IF(Intermediate Frequency) detectors(130,170) detect IFs of the main and sub channels selected in the first and second tuners(120,160), to output main channel and sub channel CVBSs(Composite Video Blanking Signals). A noise detector(140) detects a noise level of the main channel CVBSs output from the first IF detector(130). And a microcomputer(150) decides an electric field size of a currently inputted RF signal according to a noise level value of the main channel CVBSs detected in the noise detector(140) and an AGC voltage level output from the first tuner(120), if the user turns on the TV or changes a channel, to output a control signal to turn on/off the wideband amplifier(100).
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