摘要 |
A high frequency amplifier. The amplifier includes two transistors for signal amplification, and input and output matching circuits. There are variable capacitors and resistors in the matching input and output circuits. A received signal strength indicator receives the band-pass filtered intermediate-frequency signal and generates an indication signal corresponding to the amplitude of the received signal. The variable capacitors and resistors are tuned by the indication signal from the received signal strength indicator. Thus, the gain of the high frequency amplifier is automatically controlled.
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