| 摘要 |
PURPOSE: An RF(Radio Frequency) transmitter in a mobile communication system is provided to process 1.8GHz and 1.9GHz RF signals selectively and compensate gain of the RF signal according to the change of temperature, thereby detecting the gain value of the RF signal more exactly. CONSTITUTION: An amplifying unit(100) receives and amplifies the RF signal from an RF transmission terminal, and then transmits the amplified signal to a transmission filter(200). The filter(200) passes through only the specific band after receiving the amplified RF signal. A coupler(300) installed within an output detector(300) detects a part of the RF signal from the filter(200) and transmits the signal to a temperature compensation circuit(320). The circuit(320) maintains the gain of the RF signal being changed by the temperature constantly after receiving the RF signal detected from the coupler(310) and then outputs the signal to a detector unit(330). The detector unit(330) converts gain of the RF signal received from the temperature compensation circuit(320) into a DC voltage and then outputs the DC voltage to a frequency selection unit(340). The frequency selection unit(340) converts the DC voltage value according to the frequency band of the RF signal into a constant level and then outputs the converted value.
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