A circuit includes an oscillator, a variable phase adjuster and a feedback loop. The oscillator is configured to provide an RF signal, wherein the oscillator is configured to operate in a free-running mode of operation. The variable phase adjuster is configured to provide a phase adjusted signal, a phase of which is shifted with respect to a phase of an output signal of the oscillator, or with respect to a phase of a signal derived from the output signal of the oscillator. The feedback loop is configured to provide a control value for controlling the variable phase adjuster based on the phase adjusted signal and a reference oscillator signal to counteract a phase error of the phase adjusted signal.