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Noise figure circles

Rewrite (174) as
Re-arrange (176), we have
which represents a set of circles on text_wrap_inline2883 plane. Note that for a given noise figure F, i.e., a given text_wrap_inline3337, the circle provides the corresponding values of source reflection coefficients text_wrap_inline2883.

For each value of F or text_wrap_inline3337, we have a corresponding F circle with


Note that the centers of F circles are always on the line drawn between text_wrap_inline3319 and the origin of the text_wrap_inline2883 plane. The radius of F circle is getting bigger for a larger F. When text_wrap_inline3357, the F circle becomes a point on text_wrap_inline3319.