A coaxial TL with a Z0 of 50-Ω is connected to the 50-Ω output of a signal generator, and also to a 20-Ω load impedance. Calculate the mismatch loss.

To calculate the **mismatch loss** for the given transmission line (TL) system, we need to determine the amount of power lost due to the impedance mismatch between the load and the characteristic impedance of the transmission line.

### Step-by-step solution:

1. **Reflection Coefficient (Γ):**

   The reflection coefficient \(\Gamma\) is calculated using the formula:
   \[
   \Gamma = \frac{Z_L - Z_0}{Z_L + Z_0}
   \]
   where:
   - \( Z_L \) is the load impedance (20 Ω)
   - \( Z_0 \) is the characteristic impedance of the transmission line (50 Ω)

   Substituting the values:
   \[
   \Gamma = \frac{20 - 50}{20 + 50} = \frac{-30}{70} = -\frac{3}{7} \approx -0.4286
   \]

2. **Mismatch Loss:**

   Mismatch loss (in dB) is given by the formula:
   \[
   \text{Mismatch Loss (dB)} = -10 \log_{10}(1 - |\Gamma|^2)
   \]
   First, calculate \(|\Gamma|^2\):
   \[
   |\Gamma|^2 = (-0.4286)^2 = 0.1837
   \]

   Now, substitute into the mismatch loss formula:
   \[
   \text{Mismatch Loss (dB)} = -10 \log_{10}(1 - 0.1837) = -10 \log_{10}(0.8163)
   \]
   \[
   \text{Mismatch Loss (dB)} = -10 \times (-0.0886) = 0.886 \, \text{dB}
   \]

### Result:
The mismatch loss is approximately **0.886 dB**.

Would you like further clarification or additional details on any step?

Here are five related questions you might find helpful:
1. What is the physical significance of the reflection coefficient in transmission lines?
2. How would the mismatch loss change if the load impedance increased?
3. What are some practical methods to minimize mismatch loss in transmission lines?
4. How does the reflection coefficient affect power delivery to the load?
5. What is VSWR (Voltage Standing Wave Ratio), and how does it relate to mismatch?

**Tip:** Minimizing mismatch loss can be achieved by using impedance-matching techniques, such as matching transformers or tuning stubs, to ensure maximum power transfer.

Calculate the mismatch loss in a coaxial transmission line system with a 50-Ω characteristic impedance connected to a 20-Ω load. This detailed solution involves reflection coefficient and logarithmic functions, suitable for undergraduate-level electrical engineering students.

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