| 摘要 |
PURPOSE:To prevent waveform degradation dependent upon multipath reflection, by connecting the coaxial cable, which is terminated with a variable resistor, to the connection point between the buffer circuit of output impedance 0 and a summing amplifier. CONSTITUTION:Summing amplifier 501 and coaxial cables 509-511 of characteristic impedance Z0 are connected to the output terminal of buffer amplfier 500 of output impedance 0. The impedance at the view from coaxial cable input point 519 to resistor 515 is (R3+R1/R2) because the output impedance of amplifier 500 is 0. Since this value is fixed independently of the state of the reflecting circuit dependent upon other coaxial cables, this value can be equal to the characteristic impedance of coaxial cable 509. Consequently, multipath reflection can be prevented. |
