Question

A transmission line has a VSWR of 2 then the reflection coefficient is

• A. \(1/2\)
• B. \(0\)
• C. \(1/4\)
• D. \(1/3\)

Hint:

Use VSWR relation to find reflection coefficient.

Answer 1

The Correct Option is D

Step 1: Relate VSWR to normalized load impedance.
For a purely resistive load $Z_L = R_L$ greater than $Z_0$, the VSWR equals the normalized impedance: $VSWR = R_L/Z_0$. With $VSWR = 2$: $R_L = 2Z_0$.

Step 2: Substitute into the reflection coefficient formula.
$\Gamma = \dfrac{Z_L - Z_0}{Z_L + Z_0} = \dfrac{2Z_0 - Z_0}{2Z_0 + Z_0} = \dfrac{Z_0}{3Z_0} = \dfrac{1}{3}$.

Step 3: Confirm the result.
Check: $VSWR = \dfrac{1+1/3}{1-1/3} = \dfrac{4/3}{2/3} = 2$ $\checkmark$. \[ \boxed{\dfrac{1}{3}} \]