Optimal noise matching for a phased array feed

From these results, it can be seen that the best overall performance is obtained with the multi-beam average optimal impedance matching condition. The beam equivalent receiver noise temperature realized with the active impedance match is comparable, but for a PAF the active reflection coefficients for some array elements have undesirably large magnitudes. These results indicate that the multi-beam average optimal match provides a stable, practical noise matching condition for phased array feeds which largely overcomes the noise penalty associated with mutual coupling.