Abstract: The present invention relates to methods and devices for such control and supervision of an oscillator signal from a controllable oscillator that is done mainly to control the frequency variation of the oscillator signal. According to the invention, the controllable oscillator is controlled by a controlling voltage, which in turn is modified by a correction signal, generated in a control loop. A time discrete representation of a secondary phase is generated in the control loop, the secondary phase corresponding to a frequency being the difference between the frequency of the oscillator signal and a constant frequency. A time discrete approximation signal is generated in dependence of the time discrete representation of the secondary phase. A time discrete error signal is generated in dependence of the time discrete approximation signal, the time discrete error signal indicating the difference between the actual frequency slope of the oscillator signal and a desired frequency slope.

Abstract: Method and device for reducing, in a radar system, the influence of distortion which has arisen in signals in signal-generating and signal-processing parts of the radar system by firstly applying a first random phase rotation to a signal before a first signal-processing. After the first signal-processing, the signal is phase-rotated with a second phase rotation which has the same phase rotation value as, but the opposite sign to, the first phase rotation. Thereafter, a transmission pulse, created from the signal, is emitted from the radar system and is reflected off targets or objects and is received by the radar system. A third random phase rotation with a second phase rotation value is applied to the received signal before a second signal-processing. After the second signal-processing, the received signal is phase-rotated with a fourth phase rotation which has the same phase rotation value as, but the opposite sign to, the third phase rotation.

Abstract: A method for reducing the influence of distortion product that are formed in conjunction with the analogue-digital-conversion of samples of an electric signal, from which signal two quadrature signals are formed prior to the conversion process. The quadrature signals are phase modulated prior to the conversion process and are phase demodulated subsequent to this conversion process, by phase-shifting the signals by a value which is changed randomly for each new sample. The energy content of individual distortion products is distributed over a broadband this in this way. This is due to correct demodulation of the useful signal, i.e., the fundamental tone, whereas harmonies and intermodulation products will have a residual phase modulation subsequent to the phase demodulating process.