Patent ID: 7190226

Claim:
A differential amplifier comprising: (a) first and second transistors having respective first and second drains through which respective first and second drain currents flow, the sum of the first and second drain currents defining a relative constant; (b) first and second variable drain impedances respectively coupled to the first and second drains, each of the variable drain impedances having an inductance (L), a capacitance (C) and a resistance (R), wherein at least two of said R, L and C are adjustable so that a first output voltage versus input voltage transfer function of the differential amplifier can be tuned at least at 0 Hz (base frequency) and at a higher frequency; and (c) at least first and second different output tapping terminals provided in each of the first and second variable drain impedances so as to respectively output from each of the first and second variable drain impedances, corresponding first and second output signals having respectively different magnitudes.