Fault detection device

A fault detection device for detecting a fault of an antenna, comprising:

• a central processing unit (CPU) configured to detect the fault;
• and
• an integrated circuit (IC) configured to:
• adjust a frequency of a carrier wave;
• modulate the carrier wave with an input signal;
• amplify the input signal that is modulated to generate an output target signal and supply the output target signal to the antenna;
• and
• measure an antenna current that flows through the antenna, wherein
• while the IC executes a test signal supply process for changing the frequency of the carrier wave within a frequency range predetermined as a range of a resonance frequency of the antenna, modulating the carrier wave with a test signal as the input signal, amplifying the carrier wave that is modulated, and supplying the carrier wave that is amplified as the output target signal to the antenna, the IC measures the antenna current corresponding to the frequency each time the frequency of the carrier wave is changed, and
• the CPU detects the fault caused by a difference or a change in a characteristic of the antenna by using a value of the antenna current on a larger side among the antenna currents measured during execution of the test signal supply process.

A fault detection device comprising a processor and a memory, the memory storing instructions configured to, when executed by the processor, cause the processor to:

• execute a test signal supply process for changing a frequency of a carrier wave within a frequency range predetermined as a range of a resonance frequency of an antenna, modulating the carrier wave with a test signal as an input signal, amplifying the carrier wave that is modulated, and supplying the carrier wave that is amplified as an output target signal to the antenna;
• measure an antenna current corresponding to the frequency each time the frequency of the carrier wave is changed while executing the test signal supply process, the antenna current being an electric current that flows through the antenna;
• and
• detect a fault caused by a difference or a change in a characteristic of the antenna by using a value of the antenna current on a larger side among the antenna currents measured during execution of the test signal supply process.