continuous variable - gain low - noise amplifier . the amplifier continuously adjusts its gain between well - defined high and low values by using a cascode current - steering circuit to partition signal current between two different nodes of an output loading network . a shunt feedback network connected from an intermediate node of the loading network to the input provides negative feedback that linearizes the amplifier as its gain is decreased . the circuit degrades the noise figure at lower gains by varying the gain without directly dumping the signal current to the power supply . the circuit produces only small changes in input and output impedances and preserves an improved reverse - isolation cascode characteristic as the gain is controlled .