| 摘要 |
PURPOSE:To prevent a response signal sent from an objective responser from other response signal by providing the responser with a resonance circuit resonating with specific frequency. CONSTITUTION:A responser 202 is provided with a resonance circuit 29, and only when a specific frequency componenet is included in a signal received from an interrogator 201 through a receiving antenna 21, a resonance signal is outputted from the circuit 29, a controlling circuit 30 is controlled and a response signal is outputted from a modulator 25 and a transmitting antenna 26. Consequently a response signal sent from an objective responser is prevented from other response signals, and even when a nonobjective responser exists in front of the interrogator, a response signal from a required responser is precisely received. |
