Correct Answer - Option 2 :
\(\frac{1}{2}\)
Concept:
Linear polarization:
If there is either no phase present or 180° phase present between two component of wave.
Circular polarization:
Magnitude of both component must be equal & there should be exact 90° phase shift present.
Polarization loss factor \( = {\left| {{{\vec A}_{1n}}.{{\vec A}_{2n}}} \right|^2}\)
= |cos θ|2
θ → angle between transmitter & receiver orientation.
Calculation:
Let,
\({{\vec A}_1} = {{\hat a}_n} + 2{{\hat a}_j}\) …linearly polarized
\({{\vec A}_2} = {{\hat a}_n} + J{{\hat a}_j}\) …circularly polarized
\(PLF = {\left| {{{\vec A}_{1n}}.{{\vec A}_{2n}}} \right|^2}\)
\({{\vec A}_{1n}} = \frac{{{{\hat a}_n} + 2{{\hat a}_j}}}{{\sqrt 5 }}\)
\({{\vec A}_{2n}} = \frac{{{{\hat a}_n} + j{{\hat a}_j}}}{{\sqrt 2 }}\)
\(PLF = \frac{1}{2} = - 3\;dB\)
Note:
- PLF value lie between 0 to 1.
- No orientation mismatch between transmitter and receiver when PLF is unity
