| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a detection circuit and detection method capable of effectively extending a detectable range of the detection circuit without enlarging circuit scale. <P>SOLUTION: A detection circuit at least comprising a side coupling directional coupler 16, inserted into the subsequent stage of an amplifier 15 on a main signal line, and a detector 18, detecting a signal partially separated by the side coupling directional coupler 16, is connected to, for example, a PIN diode (p-intrinsic-n Diode) 17 as a variable resistive element whose resistance value can be changed by a control signal, in the isolation port 13 side of the side coupling directional coupler 16. A high-frequency resistance value is increased by decreasing a value of current flowing in the PIN diode 17, when a power level of a main signal is high; and, on the other hand, the high-frequency resistance value as the variable resistive element is decreased by increasing the value of the current flowing in the PIN diode 17 when the power level of the main signal is low. <P>COPYRIGHT: (C)2013,JPO&INPIT |
