An electronic circuit includes: a circuit generating first and second balanced differential input signals; a first envelope detection circuit including a first output terminal and first and second input terminals receiving the first and second input signals, respectively, via first and second impedance elements, respectively, and outputs from the first output terminal a first output signal that is the sum of the squares of the first and second input signals; a second envelope detection circuit including a second output terminal and third and fourth input terminals receiving the first and second input signals, respectively, via third and fourth impedance elements, respectively, and outputs from the second output terminal a second output signal that is twice the value obtained by squaring the average of the first and second input signals; and a differential circuit generating a differential signal from the first and second output signals.