GATE 2026 EC – Question 34
For a lossless passive two-port network, $|S_{11}|$ and $|S_{21}|$ intersect at –3 dB. For a lossy passive two-port network, $|S_{11}|$ and $|S_{21}|$ intersect at –4 dB. The percentage of power dissipated in the lossy network at the intersection frequency is ________. (rounded off to two decimal places)
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Correct answer: 20.28 to 20.48
Explanation
At –4 dB, $|S_{11}|^2=|S_{21}|^2=10^{-0.4}=0.3981$. Power not reflected or transmitted is $1-2(0.3981)=0.2038$, i.e. 20.38%.