| 摘要 |
PURPOSE: An apparatus for combining LPA(Linear Power Amplifier) composite powers is provided to combine LPAs(25W,50W,60W) having different outputs, when outputs of LPA combination powers have to be varied. CONSTITUTION: A band-pass filter filters RF signals to predetermined frequency bands. A preamplifier amplifies the RF signals and compensates gains of LPAs(Linear Power Amplifiers). An AGC(Automatic Gain Control) circuit controls the preamplifier and automatically controls the output gains of the LPAs. A separator separates the RF signals into predetermined numbers. Isolators prevent the RF signals from being backflowed after being amplified in an LPA modulator. The LPA modulator comprises the LPAs amplifying the RF signals. A delay line unit delays a predetermined time for synchronizing each LPA. A phase shifter compensates phases of each LPA in the same way. A combiner combines an output power from the LPA modulator. A breaker switch interrupts the output powers of the LPAs, when an over-current flows in a predetermined LPA. A controller receives power output information of the LPAs, and checks whether the output powers are the same as set powers. If not, the controller controls the output powers according to the set powers.
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