Abstract: A radar system for motor vehicles, with a plurality of transmit/receive units arranged on separate installation supports for installation at various locations in the motor vehicle, an evaluation system for evaluating the radar signals received on a plurality of channels in a plurality of processing steps, a first processing step delivering a digital time signal for each channel, which digital time signal represents the received radar signal, and a final processing step delivering as the result location data for individual radar objects and at least the final processing step being implemented for the plurality of transmit/receive units in a central evaluation unit with which the transmit/receive units in each case communicate via a raw data interface. The each of raw data interfaces has a serializer, which is configured to transfer raw data from the plurality of channels of the transmit/receive unit in question serially to the central evaluation unit.

Abstract: The invention relates to a radar system comprising an evaluation device (10) which determines the speed and/or the distance of at least one object to be located, on the basis of a spectral analysis of a measuring signal (h(t)) consisting of an emission signal and a reception signal (R(t)). According to the invention, means (12) are used to limit the emission time (?a on) of the emission signal (T(t)) in order to avoid aliasing effects.

Abstract: A method for detection and correction of nonlinearities in radio-frequency voltage controlled oscillators provides for division of the output signal of the oscillator, direct analysis of the divided output signal by means of a counting device, conversion of the respective counter value to an equivalent voltage value, and production of a control signal with a corrected frequency response for the oscillator by logic-link the equivalent-voltage value to a predetermined nominal value.

Abstract: A method for detecting and correcting non-linearities in radio-frequency, voltage controlled oscillators provides for digitization of the frequency signal by feeding the undelayed frequency signal and a delayed frequency signal generated therefrom into EXOR gates. The digital pulses produced thereform are converted using a low pass filter into a proportional DC voltage value which is proportional to the oscillator frequency and is used as a basis for producing a correction value for the frequency control of the oscillator.

Abstract: A radar sensor device for detecting the distance and/or the speed of an object relative to the sensor device is provided with an oscillator, which can be frequency detuned through the use of a modulation function. The radar sensor device has a power switch, which can be driven by a power control function, for varying the transmitter power. The sensor device is to be operated in an alternating fashion, through the use of a variable setting of the modulation and power control functions, in at least two different, mutually overlapping operating modes which are tuned to different measuring ranges of the sensor device.

Abstract: A method for measuring the speed (V) of a vehicle (1) relative to the ground, of the type using the deviation in frequency associated with the Doppler effect between a transmitted wave (3) sent by radar (2) solidly connected to the vehicle and a reflected wave (4) reflected by the ground, characterized in that radar of the type allowing simultaneous measurement of the relative distance (D) and the relative speed (V) between the vehicle and the ground is used, and that the distance measurement is used to validate the speed measurement.

Abstract: The measurement apparatus (1) delivers both a raw measurement d(i) of the distance and a raw measurement v(i) of the relative speed of said object with respect to the apparatus (1). According to the invention, said speed measurement v(i) is integrated over a predetermined sliding time interval, the difference of the raw distance measurement d(i) and of the integral d'(i) of the speed is formed, a mean value (C.sub.dif) of said difference is calculated over said time interval and the calculated mean (Copt) is added to the integral d'(i) of the speed to form a filtered measurement (d.sub.filt) of the object/measurement apparatus distance.

Abstract: A process for measuring the relative distance and speed of an object in relation to a periodically frequency-modulated continuous wave radar includes extracting the distance and the speed by combining beat frequencies derived from a mixture of emitted and reflected signals being respectively obtained during ascending and descending alternations of a modulation. The distance and the speed of an object at each half-period are calculated from beat frequencies of two immediately preceding alternations.