| 摘要 |
PROBLEM TO BE SOLVED: To provide a multiplexed signal level controller controlling a level of each channel component of a multiplexed signal with an RF signal as it is while realizing downsizing and low cost. SOLUTION: A branching filter 102 branches a signal inputted to a terminal A1, outputs the branched signals to terminals A3 and A4, and also branches the signal inputted to the terminal A3 and outputs the branched signals to the terminals A1 and A2. A variable filter 103 outputs a portion of an input signal as a transmitting signal and returns a portion of the input signal to the terminal A3 as a reflection signal, wherein the variable filter 103 has both a transmitting characteristic and a reflection characteristic with their center frequencies coinciding. An isolator 101 prevents an output of the reflection signal in the direction of the input signal. An amplifier 104 amplifies the transmitting signal. A control part 150 determines a center frequency of the variable filter 103, wherein the levels of respective channel signals of the transmitting signal are equal, on the basis of the center frequency of the variable filter 103, information showing a relation between transmittance and reflectance of each channel, the input signal and the reflection signal. COPYRIGHT: (C)2006,JPO&NCIPI
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