| 摘要 |
<p>A high frequency amplifying apparatus comprises: an amplifier for broadband-amplifying an input signal; a chalk coil having one end supplied with a supply voltage and the other end connected to an output of the amplifier; and an automatic gain control circuit for outputting an amplified input signal with a gain controlled in accordance with an automatic gain control voltage, having: a first diode having an anode connected to the output of the amplifier and a cathode; an impedance element, one end of the impedance element being connected to the cathode of the first diode, the other end os the impedance element being connected to the ground; and a second diode having a cathode connected to the cathode of the first diode and an anode supplied with the automatic gain control voltage. The impedance element comprises a resistor and a second chalk coil connected in series with the resistor. However, the second chalk coil can be omitted.</p> |
