Comments on "on resistor-induced thermal noise in linear circuits"

In a recent paper [1], Giannetti considered the thermal noise generated by a resistor R on a generic output port in any linear network. He reasoned that, because the contribution of the thermal noise of the resistor to the output noise of the circuit vanishes for both R! 0 and R ! 1, there should be a resistor value whose contribution to the output noise is maximal. In order to find that value, from Fig. 1 he obtained that the thermal noise contributed by R was [1, (3)]