Current-mode feedback amplifier employing a transistorized feedback network

Current mode feedback amplifiers providing a linear transfer function have the unique property, that their feedback network can be designed employing nonlinear devices instead of resistors. The paper describes a current mode amplifier employing such a transistorized feedback network consisting of n identical grounded- and one feedback transistor, yielding a gain of n+1. Control of the corresponding gate voltages makes it possible to cut off j individual transistors, thereby reducing the gain to n-j. Employing 5- and 2 GHz complementary bipolar transistors and electronic gain control, a bandwidth of 375÷300 MHz has been obtained at a variable gain between 10 and 100