- As the frequency increases, the Load Voltage decreases and the Source Voltage increases.
- At very high frequency, the Source and Load Voltage remain nearly unchanged.
- At very high frequency, the Source and Load Current also remain nearly unchanged.
- We have: ZCL= 1jω𝐶 𝐿=1j 2πf 𝐶𝐿
As the frequency increases, the capacitor impedance ZCL decreases. Thus, the load impedance decreases too. The changes in load impedance will cause the changes (increase) in the reflection coefficient. The load is mismatched so not all of the power from the source is delivered to the load.
This loss is called Return loss. Therefore, the Load Voltage decreases whereas the Source Voltage increases due to the addition of the return voltage from the load. Besides, when the load is mismatched, the presence of a reflected wave leads to standing wave where the magnitude of the voltage on the line is not constant.
- At very high frequency, ZCL ≈ 0 and the Reflection coefficient ≈ 1: total reflection.
Thus, the Source and Load Voltage remain nearly unchanged. (Load Voltage ≈ 0).