30 km microwave link design using 10 GHz carrier frequency with a maximum acceptable path loss of 169 dB.

Steps to Solve

1. Identify the Parameters
   Determine the key parameters involved in the microwave link design:

• Distance ($d$)
• Frequency ($f$)
• Maximum acceptable path loss ($L_{max}$)

2. Calculate Free Space Path Loss
   The Free Space Path Loss (FSPL) can be calculated using the formula:
   $$ L_{fs} = 20 \log_{10}(d) + 20 \log_{10}(f) + 20 \log_{10}\left(\frac{4\pi}{c}\right) $$
   Where $c$ is the speed of light (approximately ( 3 \times 10^8 ) m/s).

3. Evaluate Path Loss against Maximum Acceptable Loss
   Compare the computed FSPL with the maximum acceptable path loss:

• If $L_{fs} \leq L_{max}$, then the link can be successful.
• If $L_{fs} > L_{max}$, then the link may not perform as required.

4. Determine Link Margin
   Calculate the link margin, which is the difference between maximum acceptable path loss and free space path loss:
   $$ \text{Link Margin} = L_{max} - L_{fs} $$

5. Analyze Results and Draw Conclusions
   Based on the link margin, analyze whether the link is feasible and determine what adjustments might be needed (such as reducing distance, increasing frequency, or improving antenna gain).