| 摘要 |
PURPOSE:To obtain a RF amplifier circuit high in practical sensitivity by controlling gains of two RF amplification stages. CONSTITUTION:When the received radio wave intensity of a desired signal increases, detection output signal 19 of voltage comparator 17 is applied to AGC filter 14, where it is smoothed, and its output is passed through an ordianry AGC paht to decrease the gain of the 1st intermediate frequency amplification stage 6 first and when the received-wave intensity increases further, the gain of RF amplification stage 2 is decreased. |
