VSWR ABNORMALITY DETECTOR AND VSWR ABNORMALITY DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To detect VSWR abnormality accurately even when the VSWR is large.SOLUTION: A circulator 2 is connected with the output of a power amplifier, between a power amplifier 1 and a load circuit 10 supplied with the output of the power amplifier 1. A termination resistor 3 is connected between the termination terminal of the circulator 2 and a reference potential. A resistor temperature monitor 8 generates an electric signal by detecting the temperature which changes depending on the heating of the termination resistor 3. An atmosphere temperature monitor 9 generates an electric signal by detecting the atmosphere temperature in a range capable of neglecting the heating of the termination resistor 3. A control unit 7 determines whether or not the load circuit 10 is VSWR abnormal or not, from the difference between the temperature detected by the resistor temperature monitor 8 and the temperature detected by the atmosphere temperature monitor 9.