| 摘要 |
1,157,730. Electric impedance networks. TEKTRONIX Inc. 29 Dec., 1967 [3 Jan., 1967], No. 59144/67. Heading H3U. A transmission line is terminated by the bridged-T network shown in Fig. 3 in which inductances L 1 , L 2 are mutually coupled and in which the values of the components are such that for A.C. the termination impedance is substantially equal to the characteristic impedance of the transmission line whilst for D.C. the termination impedance is substantially equal to the resistance of the load. As shown in Fig. 1, in which the termination network of Fig. 3 is given the general reference 14, the load comprises a cathode ray oscilloscope 16 represented by a resistance 22 and capacitance 20. The transmission line comprises a coaxial cable 12 having its input connected to an electrical probe 10 represented by resistance 24 and capacitance 26. To compensate for variations in load capacitance 20 a third resistance R 3 and capacitance C 3 may be provided. A second resistance R 2 may be provided to obtain proper damping of signal reflections. The extremely high D.C. input impedance of the network 14 ensures that the signal source 10 is not appreciably loaded thereby. |
