| 摘要 |
PURPOSE: An apparatus for transmitting an RF(Radio Frequency) of a power amplifier in a mobile communication terminal is provided to considerably decrease the consumption current of the power amplifier by switching and converting the RF signal using a switching conversion unit and a residual 27 number pin among GPIO(General Purpose Input Output) ports in an MSM(Mobile Station Modem) without passing the power amplifier when transmitting the RF signal in an intermediate/strong electric field area. CONSTITUTION: An MSM(21) transmits an RF transmission signal of a user through a transmission path according to the strength of a receiving electric field and controls various signals. An RFT(Radio Frequency Transmitter)(22) converts a digital signal from the MSM(21) into an analog signal, adds a local frequency to the converted signal, and amplifies the added signal at a uniform level. The second RF transmission SAW(Surface Acoustic Wave) filer(23) converts the signal outputted from the RFT(22) into an SAW vibration signal and removes a noise component. A switching conversion unit(24) switches the signal outputted from the second RF transmission SAW filer(23) to an isolator(26) without passing a power amplifier(25) in case that the strength of the electric field is an intermediate/strong electric field. The power amplifier(25) amplifies the RF signal outputted from the second RF transmission SAW filer(23) at maximum 24dB in case that the strength of the electric field is an intermediate/weak electric field. The isolator(26) provides the amplified RF signal to only transmission path of a transmitting unit. A duplexer(27) connects the transmission unit and a receiving unit to an antenna connection line through the isolator(26) and divides the transmitting signal and a receiving signal.
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