Semiconductor device and semiconductor system

A semiconductor system comprising:

• a semiconductor device;
• a transmission antenna;
• a reception antenna;
• and
• a first sensor circuit detecting a target object,
• wherein the semiconductor device comprises an RF circuit and a microcontroller,
• wherein the RF circuit comprises:
• a transmission unit generating a transmission signal;
• a reception unit generating a first generation signal and a second generation signal;
• and
• a transmission/reception loop-back switching unit switching between a first coupling state of coupling an output terminal of the transmission unit to the transmission antenna and coupling an input terminal of the reception unit to the reception antenna and a second coupling state of coupling an output terminal of the transmission unit to the input terminal of the reception unit,
• wherein the reception antenna is an antenna receiving, as a reception signal, a reflection wave which is a transmission signal transmitted from the transmission antenna and reflected by the target object when the transmission/reception loop-back switching unit is in the first coupling state, and
• wherein the microcontroller switches the transmission/reception loop-back switching unit to the second coupling state in the case where the first generation signal when the transmission/reception loop-back switching unit is in the first coupling state is not normal, and
• executes a test of the RF circuit on the basis of the second generation signal when the transmission/reception loop-back switching unit is in the second coupling state and an output signal of the first sensor circuit.