If the magnitude of the reflection coefficient increases, what happens to the reflected power in the line?

• A. It decreases.
• B. It stays the same.
• C. It increases.
• D. It becomes zero.

Answer: (C)

In a transmission line, the amount of power that gets reflected depends on how mismatched the load is to the line. The reflection coefficient magnitude |Γ| tells us the fraction of the wave’s voltage (and current) that is reflected. The power reflected relative to the incident power is |Γ|^2, so increasing |Γ| means a larger portion of power is reflected. For example, if |Γ| goes from 0.5 to 0.8, the reflected power goes from 25% to 64% of the incident power. Therefore, when the magnitude of the reflection coefficient increases, the reflected power increases.