| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high power-durability receiving amplifier which can be increased in recovery speed while being improved in power durability and reliability. <P>SOLUTION: The high power-durability receiving amplifier includes: an input terminal 4 and an output terminal 5; a field effect transistor 1, with its gate terminal connected to one end of the input terminal 4 and drain bias terminal connected to one end of the output terminal 5; a detector 6 which is connected to the other end of the input terminal 4 and detects input power; a threshold decision means 8 which compares the input power detected by the detector 6 with a predetermined threshold and outputs the comparison results; and a source voltage driving circuit 9 which switches the output voltage to either the GND or the drain bias voltage on a basis of the comparison results from the threshold decision circuit 8 and applies the output voltage to the source terminal of the field effect transistor 1 via a recovery speed-up resistor 10. When the input voltage is lower than the threshold, the source voltage is made the same as the GND voltage, and when the input voltage is higher than the threshold, the source voltage is made the same as the drain bias voltage. <P>COPYRIGHT: (C)2009,JPO&INPIT |
