Harmonic and intermodulation distortion in "power law" devices

The paper is concerned with the calculation of the amplitudes of the harmonic and intermodulation components produced when a wave of the form e_i = E₀[1 + m₁ cos (ω₁t + α₁) + m₂ cos (ω₂t + α₂)], m₁ + m₂ ⩽ 1 is applied to a device whose transfer characteristic,may be represented by e₀ = Ke/^γ_i/, e_i ⩾ 0 The problem arises in connection with the variable-density process of recording sound on film and with the use of diodes in automatic-gain-control circuits. Analytical expressions of a general nature are derived and several special cases of significance are dealt with. The simpler results of practical importance in intermodulation-distortion testing are presented graphically.