New principle of the phase-locked loop operation

A new principle of phase-locked loop operation is presented. It is based on the specific influence of the phase feedback in oscillator system. The proposed device is a nonautonomous system of weakly nonlinear synchronized oscillators connected in a series with a general negative phase feedback of the first type. The new PLL does not contain a low pass filter and can have a greater fast-response. The phase of its output signal watches the phase of the first harmonic of external polyharmonic signal. The error of tracing depends on the amplitudes and phases of other harmonics. If the external signal includes in addition to first harmonic only second harmonic of arbitrary amplitude the phase error is absent. This PLL can operate with small external signals and filter out their harmonics.