Two coherent microwave power sources of same frequency f, each generating P Watts of average power, are combined using a four-port network in the following manner:If the S-parameter of the 4-port network is:\(\left[ {\begin{array}{*{20}{c}}0&{\frac{j}{{\sqrt 2 }}}&{\frac{{ - 1}}{{\sqrt 2 }}}&0\\{\frac{j}{{\sqrt 2 }}}&0&0&{\frac{{ - 1}}{{\sqrt 2 }}}\\{\frac{{ - 1}}{{\sqrt 2 }}}&0&0&{\frac{j}{{\sqrt 2 }}}\\0&{\frac{{ - 1}}{{\sqrt 2 }}}&{\frac{j}{{\sqrt 2 }}}&0\end{array}} \right]\) What should be the phase difference between the inputs to maximize the output at port 2 and what is the maximum power?

• A. 90°, 2P
• B. \(\left[ {90^\circ ,\;\;\sqrt 2 \;P} \right]\)
• C. 45°, 2P
• D. \(\left[ {45^\circ ,\;\;\sqrt 2 \;P} \right]\)