| 摘要 |
PURPOSE:To superimpose a signal on power by inserting a resistor to the primary or secondary side of a transformer coupling a digital signal source so as to attain impedance matching to the digital signal in high frequency without being affected by a device of power supply side. CONSTITUTION:In a figure 1 is the device at power supply side and 2 is a device at power receiving side. A signal from a digital signal source 4 flows to a capacitor 7 via a composite transformer 10 and is coupled to a DC power transmission line 8. In this case, when the value of an inductance 9 is defined as L, the characteristic impedance is sufficiently higher than the impedance of transmission line in a frequency (f) of a transmitted signal and the effect of a DC power supply 5 is neglected. Two secondary impedances of the composite transformer 10 are regarded as being added in parallel as shown in an equivalent circuit. When an impedance Z0 at the side of the transmission line 8 and a value R of the resistance 3 are defined as n2<2>R=n1<2>Z0, then the distortion due to reflection caused by impedance mismatching to a transmitted digital signal is eliminated. |
