Abstract: A voltage-controlled oscillator in which a phase shifter is connected to a ceramic piezoelectric resonator. The phase shifter has a first circuit branch containing an amplifier. A second circuit branch is connected in parallel with the first circuit branch and includes a low-pass filter connected in series with a controllable amplifier and switch. The output of the controllable amplifier is applied to a first input of the switch, and a source of reference potential is connected to a second input of that switch. The switch has an output connected to a summing element at a first input of the summing element. A second input of that summing element is connected to the amplifier in the first circuit branch. The output of the summing element is fed back to the ceramic piezoelectric resonator.