| 摘要 |
PROBLEM TO BE SOLVED: To detect with a simple configuration faults, including deterioration in a noise figure of a receiver. SOLUTION: A fault detection section 4 controls a changeover circuit 5 to select a noise generator 6, and the noise signal is outputted to a reception electric field detection section 3 via a reception section 2, resulting in that a level given to the reception electric field detection section 3 is obtained from an electric field information voltage (b) outputted from the reception electric field detection section 3, to obtain a gain G of the reception section based on the level. The gain is compared with a gain in a normal state to detect a fault of a receiver. Then the fault detection section controls the changeover circuit to select a termination resistor 7 for allowing the resistor to receive only thermal noise. Simlarly, a level received by the reception electric field detection section 3 is obtained. Since the gain G of the reception section is already known, it is possible to obtain a noise figure NF of the reception section from the gain G. |
