| 摘要 |
PROBLEM TO BE SOLVED: To provide a gain control amplifier whose output is converged a short time in spite of its long response time. SOLUTION: The gain control amplifier comprises a variable gain amplifier 1 that amplifies the amplitude of a received signal, an electric field strength detector 3 that detects the amplitude of the received signal, a comparator 4 that compares a level of the received signal with a reference level Vref, a gain control level generator 5 that increases/decreases a gain control level depending on the positive/negative polarity of a control signal, and a timing generator 6 that intermittently operates the gain control level generator 5. The timing generator 6 outputs a timing signal being at a high level for a prescribed time to control the operation of the gain control level generator 5. When the level of the timing signal is a high level, the gain control level generator 5 is in operation (1st mode). When the level of the timing signal is a low level, the gain control level generator 5 stops its operation (2nd mode).
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