Abstract: The phase and frequency comparator for controlling, as a function of the frequency (Fref) and the phase of a reference signal (Sref), the frequency (Fvco) and the phase of the output signal of a controlled-frequency oscillator comprises means (11, 12, 21, 22) for detecting in the reference signal (Sref) and in the signal from the oscillator events representative of the frequency and the phase of that signal, means (S1+, S1, 16, 17) for generating a first or second signal on the detection of an event, means (S2+, S2?, 24 to 27) for generating a third or fourth signal on the detection of an event, if the first or second signal, respectively, is generated, means for applying all of the signals (Io; Vo) generated to the oscillator, and means (13, 23) for halting the generation of the first and second signals or of all of the signals if the first and second signals or the third and fourth signals, respectively, are generated simultaneously.

Abstract: A mixer circuit with image frequency rejection comprising a quadrature phase divider (30, 30?) presenting an input connected to the input (Fi) of the mixer circuit and two outputs respectively delivering two signals in phase quadrature which are applied respectively to two simple mixers (31, 32; 31?, 32?), said mixer circuit comprising a quadrature phase and frequency divider (33, 33?) having a frequency division ratio and presenting two inputs respectively connected to the respective outputs of the two simple mixers (31, 32; 31?, 32?) and a first output delivering a first output signal (Fo) of the mixer circuit, which signal is applied to the inputs of the two simple mixers.