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of the reflected wave is the same as that of the incident wave (ρ
＝
1), no current flows through the open-circuit device, and the
reflected voltage wave is the same as the incident voltage wave.
Fig. 8.4 Signal Transmission of Transmission Line Connected through Open-circuit Device
If the transmission line is connected through a 25Ω resistor, part of the energy will be absorbed, and part of the energy will be
reflected to the signal source. The amplitude of the reflected wave is 1/3 of that of the incident wave. The voltage is subject to
180-degree difference at the resistor. The phase relationship changes with the distance of the end resistor along the transmission line.
The valley of the standing wave figure is not approaching zero, and the peak is smaller than that of the open-circuit device and
short-circuit device.
Fig. 8.5 Signal Transmission of Transmission Line Connected through 25Ω Resistor
8.1.1.4.
Impedance
The impedance is another way to express the reflection data. For impedance details, refer to the “Smith Chart Format" section of “4.7
Selection of Data Format and Scale".
8.1.2.
Summary of Reflection Measurement Expression
Various kinds of reflection data are calculated based on the same measurement data. The data relationship is shown in Fig. 8.6.
Fig. 8.6 Relationship of Reflection Expressions
8.2.
Phase Measurement
8.2.1.
What is phase measurement?
