| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve the service lifetime and durability of an amplifier by re-executing the compensation with respect to gain degradation of an amplification device, without causing acceleration of deterioration in the amplification device, regarding an amplifier with gain compensation function. Ž<P>SOLUTION: A voltage signal Vcont, which is proportional to the DC component of a drain current Id of an amplification device 100, is applied to a variable attenuator 102 so as to compensate for the gain of the amplification device 100, by controlling an attenuation amount of the variable attenuator 102 by the voltage signal Vcont. The voltage signal Vcont is inputted to an upper-limit value comparator 103 and a lower-limit value comparator 104. When the voltage signal Vcont becomes greater than or equal to an upper-limit reference value, or becomes lower than or equal to a lower-limit reference value, the upper-limit value comparator 103 and the lower-limit value comparator 104, respectively, output an output signal of the logical "1". Their output signals are composited as a single OR output signal by the wired OR so as to be outputted as a gain-compensation-state notifying signal for notifying the host apparatus of a gain-compensated state. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
