Design of microwave transistor amplifiers with optimum cascaded gain and noise

The design of microwave transistor amplifiers with optimum cascade noise and gain is described. By treating two stages at a time, the condition for the second stage's noise figure needed to satisfy the total cascaded gain and noise performance is derived. Two optimal solutions are possible: Minimum cascade noise figure or maximum available cascade power gain without increasing the cascade noise over that of the minimum noise design. A design example is submitted showing the effectiveness of the proposed method in optimising the gain and noise of cascaded amplifier stages. The approach can be extended to noise temperature and multiple cascaded stages including passive blocks without any loss of generality.