Abstract: Input and output electrodes of a microwave, active semiconductor amplifying element are shunted to ground by resistive means having values selected to assure unconditional stability of the semiconductor amplifying element. The resistive means and active element are located in a common semiconductor package having three output terminals respectively connected to input, output and common electrodes of the amplifying element. The resistive means includes, in certain embodiments, first and second resistors respectively shunting the input and common electrodes and output and common electrodes, with values respectively selected to provide relatively high efficiency and low noise characteristics for the amplifying element.