Mixer with exponentially variable gain

摘要

An exponentially variable gain mixer comprises a variable gain mixer receiving an input differential signal to be amplified and producing an amplified differential output signal in function of a differential modulation signal and of a control voltage, at least an oscillating circuit generating an alternated differential signal, a correction circuit input with an external gain variation command and with the alternated differential signal for producing the differential modulation signal and the control voltage. Differently from comparable known circuits, the modulator does not require a peak detector because the correction circuit comprises a first amplifier input with the external gain variation command that generates the control voltage and a bias voltage as differential output signal, and a second differential amplifier referred to the bias voltage, input with the alternated differential signal that outputs the differential modulation signal.