| 摘要 |
PURPOSE:To enable a discriminator which uses a microwave to synchronize easily an interrogator and a responder with each other by reading a memory with a clock signal which synchronizes with an interrogation signal and by generating an answer signal by two oscillators. CONSTITUTION:Interrogator 11 generates microwave carrier signal fc, and clock signal fs to be used by responder 12 and the both are mixed and sent out. A radio wave arriving at interrogator 12 is partially rectified via demodulator 20 to be used as a DC power source. The remainder passes through filter 22 to obtain clock signal fs, which is supplied to read-only memory 24 via counter 23. In memory 24, the code characteristic to responder 12 is stored and according to the memory contents, switches 25 and 26, and oscillators 27 and 28 operate by turns to send out the characteristic responder signal, FSK-modulated by output signal f1 or f2, from antenna 30. This signal is supplied to signal processing part 35 via mixer 32, filter 33 and detector 34 of interrogator 11 to discriminate the code characteristic to the responder. |
